Garand load

[BoogieMan]

Is comercial garand ammo any safer? I have heard issues with commercial ammo for other guns many times. Reloading for this rifle is not a big deal to me, I don't plan on using it for any competition shooting. It's just a range toy that will see limited use. Also are slam fire risks minimal as long as it's not loaded by slingshot ting single rounds.

[mehavey]

About the only commercial ammunition (that I know of) loaded to
the pressure/burn-rate specs is Federal "Garand-Specific ammunition"
http://www.midwayusa.com/product/953...l-metal-jacket

At the same time, I have long asked (this board amongst others)
what primers are used in this Federal product, but never gotten
an answer.

Anyone know?

[chiefr]

My advice for reloading for Garands/M1as is to

1. Full length resize in a small base die

2. Trim cases

3. Clean primer pockets, ream to depth

4. Prime all cases by hand, verify that all primers are below the case head, and use the least sensitive primers you can find.

5. Use IMR4895/AA2495/H4895 powders.

6. Seat the bullets to magazine depth, no longer than 3.3” inches for the 30-06, no longer than 2.8 for the 308, shorter is fine.

+1 Spot on Slamfire

[condor bravo]

Likewise I am unaware of the primer used in the Federal American Eagle Garand ammunition but would think they would be milspec primers. I have used a quantity of the ammunition and my only objection is the crimped in primer. I would venture to say that these rounds are as safe to use as military. The ammunition not to use is commercial '06 rounds that might be loaded with slow burning powder resulting in high port pressure and damaging the operating rod. However have.never heard it said how much firing would be needed to actually do the damage. Rounds in question would likely be those with heavier bullets.

[TimSr]

Every time I see one of these threads, I tiptoe into the gun room and hide the Garand under a pile of other guns.

Maybe I'll just forget it over time.

I remember the good ol' days when I could just "load some 30-06" and shoot it.

Everyone wanst to be helpful, but sometimes answers to simple questions can become so overwhelming and complicated that the OP gets frustrated and buys factory ammo as he is lead to believe that you need a 4 year degree to handload for your Garand.

1. Full length resize in a small base die

2. Trim cases

3. Clean primer pockets, ream to depth

4. Prime all cases by hand, verify that all primers are below the case head, and use the least sensitive primers you can find.

5. Use IMR4895/AA2495/H4895 powders.

6. Seat the bullets to magazine depth, no longer than 3.3” inches for the 30-06, no longer than 2.8 for the 308, shorter is fine.

To the OP, ^^^^this is all you really need for now.

[Unclenick]

I suspect the primers are Federal. They use the Federal 210M in Mk.316 mod.0 sniper ammo, and it gets shot in M14's as well as in the M24 sniper system it was intended for. They probably got a special waiver of the military sensitivity spec for it. Federal has long held that their primers were no more prone to slamfire than others, but rather it was just more people using their primers at matches that lead to that impression. Two things suggest Federal is wrong about that:

First, every gun that has ignition failures (tuned revolvers are the most common example) has fewer of them with Federal primers, indicating their greater sensitivity. Second, Federal came out with the GMM205MAR primer, a military sensitivity spec version of their 205M primer designated for the AR, a rifle less slamfire prone than the M1 and M14. Why do that if there's no sensitivity issue?

As to standard dies, you have to realize work-hardened brass is springy. The tighter you squeeze it, the more spring you get, up to a point, but one not normally reached by the resizing operation. As a result, range pick-ups and military and police once-fired brass can found that was fired in a wide chamber and that a standard sizing die simply will not return to width dimensions fully inside the SAAMI (and military; they appear to match in this regard) maximum case diameter specs. All sizing dies are narrower than that spec, but how much narrower depends on how much spring-back the designer allowed for. In general, the vast majority of the time, a standard die will make a case small enough for your particular chamber if the case was fired in your particular chamber originally. That cannot be guaranteed of that for one fired in some other chamber. If you let range pickups get mixed in with your own brass, be aware of this.

To those saying the military spec primers or small base dies are unnecessary because they've never had a problem: that's what is called anecdotal evidence. Most of us have never been in an airplane crash, but how many of us believe they can't happen to anybody, anywhere, anytime just because it hasn't happened to us? Anecdotal evidence can suggest a subject for study, but is of no use assessing risk, whether it's positive or negative. You need statistical evaluation that includes the successes and failures, even rare ones, to assess risk.

Do I ride airplanes anyway? Yes. I am willing to assume that risk for myself. I also shot Federal 210M primers in my Garands and M1A for years without incident. Do I still do that? No. Why not? There are three reasons I no longer use those Federal in my gas guns: One, I recognize the limited value of my personal anecdotal experience in proving anything. Two, with the availability of military sensitivity spec primers for handloaders, I have a simple way to make the small risk even smaller. If I had a simple way to further reduce risk in the airplanes I ride in, I would do that, too. Third, board member Hummer70 tells of having once investigated an out of battery fire that killed the soldier to the right of the ejection port of the gun it happened in. Even if I don't mind taking a small extra risk upon myself, I don't feel I have any right to decide the junior shooting on the firing point to my right should have to assume extra risk just because I want to; and certainly not when I can avoid it for less than an extra penny a shot. I just don't feel it would be responsible to do otherwise.

[T. O'Heir]

"...there is no such thing as the slam fire issue..." Should have put in, "with the rifle".
"...small base die..." Aren't necessary. Millions of rounds have been reloaded and fired with no fuss long before there was such a thing.
An M1A is not an M1.

[kraigwy]

I'm certainly glad I started and did most of my Garand/M14 shooting and reloading before the internet came out. I'd have been scared to death.

The firing pin on this rifles will not travel far enough to set off a properly seated primer (any primer I know of) unless the bolt is locked up. The L shaped leg of the firing pin wont allow it.

The little book that comes with CMP Garands show this.

High primers can cause slam fires. Loose primer pockets and backed out primers may cause this. Or a too long firing pin.

You can argue tell the cows come home, it isn't gonna happen.

If you're still concerned, call the CMP Custom Shop and ask the armors. This topic comes up in the Advanced Maint. Courses (or at least it did mine), and the answer is aways the same, as I mentioned above.

This crap scares and confuses new Garand shooters.

[mehavey]

Well, it scares me as an old Garand shooter.
So ....

- I FL/SB resize
- Toss after a half-dozen firings
- Hand prime/thumb-feel each case
- Use [the harder/less sensitive] ] CCI primers at a minimum/Mil-Spec'd whenever available



- ...and read the weather reports before waggling my rudder to the towplane pilot

[Unclenick]

Kraigwy,

Garands are aging and few own the gauges necessary to check them comprehensively. Additionally, a lot of aftermarket parts are in them now as well.

In general, I submit that what might have been true of a military armorer maintained rifle fifty years ago, need not be true of it today. The example I gave of the issued LC ammo going off at the load command at the ORPA Spring DCM shoot at Perry in '89 (have since checked the date) was an example. The guns were all DCM owned and all had military parts, but a lot of them were so heavily used they were getting very loose. When the last time was that they had been inspected to see the safety bridges were not bent or broken, I don't know.

That OOB fires happened twice to Slamfire proves that they can happen. And those are not the only ones that have ever been reported. You can say they can't happen, but then you have to come up with an alternate explanation for where all the noise and smoke and little pieces of metal came from and why there wasn't a live round left over at the end of the event.

As near as I can tell, the explanation is that something causes the feed to be significantly interrupted after the bolt has picked up some speed, so the extractor snaps over the rim of the cartridge before the leg of the firing pin arrives at the safety bridge. I imagine the neck and shoulder of the last cartridge staying behind in the chamber is one candidate for producing this effect, though probably not the only one. In that instance you could blame the owner for reloading the same case once too often, and he would have to have the bad luck that it decided to produce that particular failure, so it would have to be a pretty rare event. And thank goodness it is. It's just not a zero probability.

Originally Posted by T O'Hier

"...small base die..." Aren't necessary. Millions of rounds have been reloaded and fired with no fuss long before there was such a thing.

And airplanes fly millions of miles a year without crashing. What's your point? It certainly isn't proof that a problem with fat cases never happens to anyone; just that it's not usual.

I made the mistake of buying a couple of Wilson Garand barrels once whose roughed chambers were so wide at the base that my headspacing reamer didn't touch them until half way to the neck. Talk about fat cases. My dad bought a .308 Garand chambered by a local guy who didn't know what a floating reamer holder was for and used a cheap Chinese tailstock chuck as the reamer holder. I had to grind out the inside of his RCBS Precision Mic base because the cases came ejected too fat to fit into it. Try sizing those to fit in a match rifle chamber with a standard sizing die.

"Utopia is a place where everyone always has everything they want, and nothing ever goes wrong. Utopia is not one of the options." David Bergland

Look, none of the things we are talking about are commonplace. I still get in airplanes and I still shoot Garands. Some degree of risk is incurred in everything we do, and as any list of fatal accidents reveals. Firearms accidents are alsway far from the top of such lists. Garands, specifically, may never even have made the list, for all I know. If that's right, I'd like to see it stay that way. But just because the Garand's safety mechanism has proven very reliable doesn't mean we let the muzzle cover somebody we aren't fighting when it is engaged.

In that same spirit, there's just no good purpose served in letting even a small risks be higher when the added cost of avoiding that is so trivial. And even if you don't believe the commercial version military hardness primers actually add a layer of safety, then consider that should a slamfire or an OOB fire in your rifle ever actually injure somebody, even if the actual cause was a high primer, just imagine what the injured's attorney will do when he learns from your past posts that there are special primers made that claim to make these gun's more safe and that you knew it and that you knowingly eschewed using them because you disagreed with the primer maker's "experts". You may curse the primer manufacturers for having created that hazard, but there it is, just the same.

[kraigwy]

Sir, I agree Garands are aging. I had one. I got it in 81 from the CMP and shot the crap out of it, When I was running sniper schools for the Guard using M1C/Ds many a day I shot it until sap boiled out of the stock. Then after retiring from the Guard, and getting my DR badge, CMP games became popular and I started shooting Garand Matches.

Before my eyes I saw my Garand age further, I saw the results on the target. Groups opening up is a sure sign. So I bought a barrel at the OK City game and the CMP put it on for me. The barrel is the only part that "gave up"

When metal ages and wears out, it doesn't shrink, it stretches or wears, making the tolerances looser. Firing pins wear, they don't grow. Its the firing pin that sets off the primer. If it wears it gets shorter not longer.

The firing pin is "L" shaped, the (non-firing) end is bent so that it holds the firing pin to the rear until the bolt is locked. Enless the firing pin had been modified or that L section breaks off (never heard of that happening) it cannot hit the (properly seated) primer until the bolt locks into battery.

High primers may go off by being smashed by the bolt face and the bolt slides home, but the firing pin wont set it off.

Ammo does cause problems, that I agree. Even factory ammo.

Back in the 70s or club was having a leg match. Back then DCM furnished the ammo and you had to shoot it. Most people shot Garands in EIC matches back then, there were a few Springfields and some service members shot M14,s but the Garand ruled.

In this match, not of our Garands worked. We checked and found out the somebody failed to put flash holes in the LC service ammo.

I was able to furnish guard Match Ammo from my Sniper school to allow the match to go on.

But that was the ammo, not the Rifle.

I have a Garand I put together with new, near perfect parts at the CMP AMC last month. Saturday I shot a Garand match followed by NMC. My new Garand wouldn't cycle my New Win Brass loaded with 47 grns. of 4064 pushing a 168 Horn. A-max bullet. That's a near perfect load for a M1, but not mine.

I guess you can say, it was the rifle, but it was my fault. At the AMC class the instructor/armor's told me my Head Space was too tight. I knew it, I did it purposely. I always set tight head space on my target rifles. It does make them more accurate. But that was my doing, not the design of the rifle, not that the rifle was wore out.

You'll not find a safer rifle then the USGI Garand/M14 series rifle. If it slam fires its not the fault of the rifle or firing pin.

Hatcher, in his "Hatcher's Book of the Garand" goes into great detail on the safety aspect of the Garand and how the Firing pin/bolt are designed so as the firing pin cannot pierce a primer until the bolt is locked into battery.

here are a picture I took at the AMC course showing the design of the firing pin/bolt of the M1. As I mentioned the little booklet the CMP sends out with the Garand shows a better picture, and explains it better.

http://photos.imageevent.com/kraigwy...e/IMG_1049.JPG

[Slamfire]

The firing pin on this rifles will not travel far enough to set off a properly seated primer (any primer I know of) unless the bolt is locked up. The L shaped leg of the firing pin wont allow it.

Not at all. The firing pin does not encounter the receiver bridge until cam down. Till then, the firing pin is totally free floating. Out of battery slamfires occur prior to cam down, that ought to be obvious. Of all the mechanisms on the market, and I mean all, Garand mechanisms have the most reported incidents of out of battery slamfires.

The receiver bridge was and always was, a firing pin retraction bridge. I am of the opinion that calling it a "safety" bridge is a creation from the early 60's. When I examine John Garands' patent, the functions of the firing pin tang and the firing pin retraction bridge are explicitly spelled out and neither as a firing pin block. Its primary function is to retract the firing pin at unlock. There is a slot allowing the firing pin to go forward when the bolt is in battery, but the function of the whole as a firing pin block is not claimed. The extractor is claimed as a means of holding the firing pin.

Patent 1 892 141 Semi Automatic Rifle. J. C. Garand Dec 27 1932

The firing pin is formed at its rear end with a laterally extending had 72 adapted to contact a projection 73 formed in the receiver when the bolt is in unlocked position so that the firing point is retracted into the bolt, but the head is cut away at 74 to pass such projection when the bolt is locked to permit the pin to be moved to its extreme forward or firing position.

"I claim":
5. The combination with a gun provided with a receiver, of a bolt receiprocable in the receiver, a firing pin reciprocal in the bolt, a laterally extending head for the pin and means in the receiver to engage the head on rocking of the bolt to unlocked position to retract the pin

6. The combination with a gun provided with a receiver, of a bolt reciprocable in the receiver, a firing pin in the bolt, an extractor carried by the bolt, and means on the extractor to prevent rotation of the pin with respect to the bolt.

7. The combination with a gun provided with a receiver, of a bolt reciprocable in the receiver, a firing pin in the bolt, an extractor carried by the bolt, and means on the extractor cooperating with the pin to limit movement thereof.

8 The combination with a gun provided with a receiver, of a bolt reciprocable in the receiver, a firing pin in the bolt, an extractor carried by the bolt, and means on the extractor to limit reciprocatory movement of the pin with respect to the bolt and prevent rotary movement thereof with respect thereto.

The Garand mechanism is an early semi automatic weapon design. It is my opinion that later mechanisms incorporated more thought into preventing incidental firing pin contact with the primer prior to lug engagement. As an example, AR mechanisms fully retract the firing pin until cam down. This is a very positive means of preventing firing pin initiated out of battery slamfires. If the firing pin is fully behind the bolt face till lug engagement, the primer is 100% protected from incidental contact with the firing pin. Credible out of battery slamfire incidents in AR’s are very rare. Armalite provides extensive large print warnings not to remove the firing pin spring in their AR10 actions. Technical Note 10: Prevention of Slamfires explicitly states that the firing pin spring reduces the inertial impact energy to a very safe level and almost always cures slamfires. http://www.armalite.com/images/Tech%...s%20981226.pdf I don’t believe their statement that Government and commercial large rifle primers are not “Hardened” in the same way as the Government #41 primer. (Based on talks with CCI, commercial large primers are more sensitive than the #34 primer) Armalite is correct that free floating firing pins will lightly impact a cartridge primer and, very rarely, cause the primer to ignite. Their technical bulletin advises to always feed from the magazine, because the friction of stripping a round from the magazine slows the bolt, and to never, ever, remove the firing pin spring. In Technical Note 59: AR-10(T) Addendum to USMC M16A2 Technical Manual there is a picture of the Armalite spring on a firing pin and the large print notice: ”WARNING: THE FIRING PIN SPRING IS AN IMPORTANT SAFETY DEVICE AND MUST NOT LOOSE, REMOVED, OR LOST” From Armalite Operator’s Manual http://usarmorment.com/pdf/AR10M15OperatorsManual.pdf

The AR-10 firing pin spring reduces the firing pin mark on the primer of a chambered cartridge that is chararacteristic of M-16 type rifles, and the “slamfire” possible with overly sensitive primers”. “THE FIRING PIN SPRING IS AN IMPORTANT SAFETY DEVICE AND MUST NOT BE LOOSE, REVERSED, REVOVED, OR LOST.”

Simonov’s SKS and the Fabrique Nationale FAL were extremely hard to find in the US prior to the Reagan administration, but since then they were imported in mass quantities. There is a domestic manufacturer of the FAL so supplies won't be as tight as they were prior to the 1980's. Both mechanisms are examples of designs that use a titling breech face to reduce the possibility of an out of battery slamfire. In both of these designs the bolt face is out of perpendicular from the case head until the bolt is in battery. This keeps the firing pin out of parallel with primer until the bolt faces rises as the bolt goes into battery. Both of these rifles have free floating firing pins, the FAL has a firing pin spring to reduce the chance of a slamfire and so do some models of Russian SKS’s. I never saw a Chinese SKS that had a firing pin spring and there are plenty of in-battery slamfires reports, most particularly the SKS, due to firing pin inertia with either of these models. Murray’s sells a SKS firing pin spring to reduce firing pin impact on bolt closure.

http://www.murraysguns.com/sksown.htm.

There are a few firearm designs which don’t manually retract the firing pin and the SKS and FAL are among them. For these designs it is safety critical to keep the firing pin channel clean to prevent the firing pin from being wedged in a forward position. Here, Murray performs an insanely risky test with an SKS. He has wedged the firing pin forward and the gun fires until the rifle is empty. https://www.youtube.com/watch?v=xj3QtnUWCwQ The primary reason the rifle does not have an out of battery slamfire is due to the titling breech face design of the mechanism, but given a long enough firing pin, I don’t see any reason why an out of battery slamfire could not happen.

Here is a video of an SKS which the owner claims is well maintained and it slamfires in battery. https://www.youtube.com/watch?v=mPn97vz0Vyw

D.J Saive, the designer of the FAL, in the earliest version, the FN49, inside the patent there is an explicit claim for a firing pin blocking feature.

Tilt Locking Breechblock for Automatic Firearms D. J. Saive July 18, 1950, 2,515,315

The spring 32 also forms a safety device (Figure 14) for preventing firing when the breech block is unlocked. As shown in 'Figure' 14, the firing
pin 31 has a groove 31a in it and the spring 32 has a lug 32a on it which acts as a safety and, by engaging in the groove 31a, holds the firing pin against forward movement when the breech block is unlocked . When the breech block is not locked (Figure 8) the rear end of the slide projects beyond the rear end of the firing pin thus preventing the striker from striking said firing pin.

You can see a picture of the firing pin safety stop here:

http://milpas.cc/rifles/ZFiles/Semi-...isassembly.htm

Unfortunately, as anyone who has searched, the firing pin safety stop has not been positive in function as there are lots of accounts of out of battery slamfires in the FN 49. One cause is a weak firing pin that breaks and sticks out through the bolt face, but there are a number of accounts where the firing pin was found to be intact and not stuck within the barrel channel.

Something must have changed with the FAL, while in battery slamfire accounts are easily found, out of battery slamfire accounts are rare.
As can be seen with this FAL bolt, when it is unlocked, the firing pin center of axis is off set from the primer center. Any incidental firing pin contact is less likely to ignite the primer. Data shows that the further the firing impact is from the center of the primer, the greater the misfire rate. Primers need to be hit in the middle for positive ignition.

Another feature is that the breech face is out of perpendicular with the cartridge base. Only at lockup does the bolt face and firing pin square up. There could be out of tolerance conditions that could create incidental firing pin contact with the center of the primer, but in this mechanism, such events are rare.


FAL Bolt out of battery



FAL Bolt in battery


I am impressed with the HK roller bolt actions. The primary concern of the German designers was to create a rifle that could be quickly and inexpensively mass produced, a goal they achieved, and they also produced an easy to maintain and safe rifle. I have never heard of any in battery or out of battery slamfire events in the roller bolts and I am of the opinion that a firing pin induced out of battery slamfire is totally impossible in this design without part breakage. The firing pin absolutely cannot move forward of the breech face until the rollers are in battery:



These are pictures of the bolt mechanism of my PTR 91, you can see the firing pin spring, “connecting rod” and bolt.





The firing pin mainspring is very strong, much stronger than I have found on any of the actions I own. To call this firing pin “free floating” is almost an oxymoron as spring tension must keep the firing pin in place regardless of firing pin inertia.

Of the military actions on the market, the Garand mechanism has the most reports of slamfires. One reason has to be the hundreds of thousands of Garands that have been imported and are now in civilian hands. Another reason is that the Garand action has a long free floating firing pin. This mechanism does not positively hold the firing pin throughout the feed cycle and the firing pin is always in line with the centerline of the cartridge case. Due to these characteristics the Garand mechanism will not only slamfire in battery, but out of battery. I am of the opinion that the US Army controlled slamfire rate in the Garand (and M14) by specifying a relatively insensitive primer. I am of the opinion this was how most militaries controlled slamfires in their issue rifles: primer insensitivity. On page 58 of the April 2011 Guns Magazine Mike Venturino reports having a in battery slamfire in a K43 and SVT40 rifle with standard primers. These slamfires ended when he used #34 primers.

High primers can cause slam fires. Loose primer pockets and backed out primers may cause this.

CCI says high primers are the most common cause of misfires. There is a lot of pistol ammo cranked out on progressives with high primers, and yet, I don't read of slamfires problems in auto pistols. If high primers are the primary slamfire mechanism, which your post implies, how come semi auto rifles are the one having slamfires, and not semi auto pistols?

It is my opinion that high primers are the least likely cause of slamfires.

If you're still concerned, call the CMP Custom Shop and ask the armors. This topic comes up in the Advanced Maint. Courses (or at least it did mine), and the answer is aways the same, as I mentioned above.

Fan boys may believe whatever they want to believe. After my experiences, I consider these types delusional. I rely on observations in the real world, they base their religion on authority and ignore all evidence contrary. Did these experts ever discuss why every semi automatic mechanism in every semi automatic rifle has had a posted slamfire? I have pages of slamfire incidents that I have copied from web posts, many with factory ammunition. The world has gotten larger since the inbred world of the DCM and the NRA and their old worn out religion that slamfires are only caused by high primers and worn out receiver bridges. Prior to the mid 1990's, hardly anyone had anything other than a Garand or M1a, then the Colt AR15 monopoly was broken, good President Reagan allowed the import of huge quantities of military surplus rifles. Shooters had access to SKS's, FAL's, Russian rifles, Swedish, French, and every one of these has a slamfire incident, many with factory ammunition. Try to find an out of battery slamfire incident with one of these.

Did these CMP experts ever discuss this? These rifles were gaged for compliance, were being shot with Government ammunition in Government test, and one, slamfired out of battery. How could that have happened? I have a paper copy of this report. The Army was testing production models of H&R’s and SA’s for dimensional part compliance, (part interchangeability), such things as the thickness of the chrome coatings were measures, rifles were reassembled after gaging and underwent endurance testing.


USATECOM Project No 8F-3002-04, Comparison Test of rifles, 7.62 MM, M14 Manufactured by Springfield Armory and Harrington and Richardson Arms Company. Author G. E. Hendricks, July 1963.


At round 5271 a Springfield Armory M14 went off out of battery, with military ammunition. The report states:

“One rifle fired when the bolt was in the unlocked position causing breakage for the firing pin, extractor, bolt roller, ejector, and stock. The magazine split, causing the magazine floor-plate spring and 12 rounds of ammunition to be ejected against the bench rest from which the rifle was being fired. The case ruptured and several pieces of brass were found in the area. A broken part of piece of brass perforated a cardboard box with was position between the gunner and the proof director. The cardboard box was used as a brass catcher. Not all the broken pieces were found. Although no one was physically injured this is a seriously unsafe condition.”

So, six rifles were tested, five completed the test firing 6000 rounds each, one slamfired out of battery at round 5271, for a total round count of 35, 271. Therefore the probability of an out of battery slamfire with mil spec primers is 1:35,000.

[schmellba99]

Jeesus, I'm pretty much paranoid to shoot my Garand now. I didn't use small base dies when I reloaded, I didn't use one of the 3 listed powders, I don't have custom cut test chambers to check each and every single round to ensure that they are 100% perfect, and I didn't hand seat my primers. Come to think of it, I didn't use CCI primers either.

I'm apparently lucky that the rounds I have shot thus far have not killed me or blown up my gun.

I get making a comment about some safety aspects, but anybody reading slamfire's posts will likely burn every reloading book they have, scrap every tool they have and probably throw their gun in a lake before attempting something that apparently requires some NASA technology to accomplish.

[Slamfire]

Since this thread has entered the realm of sarcasm, maybe it is a good time to drag out of the closet a list of horrors. This is my accumulation of good M1a slamfire reports, I have a longer list of Garand slamfire posts, but I am feeling lazy about adding in the bold and quotations. The M1a bolt differs from the Garand bolt by having a roller on the end. The bolt is shorter because the cartridge is shorter. Otherwise, as to firing pin, bolt, receiver bridge, the M1a/M14 is a copy of the Garand.

There are those who make a big fuss over a Garand not being a M14, which is true, though Garands have been converted to box magazine feed. The M14 was a product improved Garand, a better gas system, a shorter and stiffer operating rod, shorter barrel, and a box magazine. Those are the major differences. A small number of parts interchange between the Garand and the M14. When it comes to the basics of firing pin retention, (none) the M14 and Garand are the same. M14's/M1a's have fewer slamfire reports, mostly due to the fact the firing pin is lighter. That makes a difference in kinetic energy.

M1a Slamfire with Prvi Partizan

http://m14forum.com/ammunition/12832...ire-today.html
________________________________________

I was shooting Prvi Partizan 168gr Match HPBT. It looked like new, bought from cabelas last week. Anybody else get em with PPU ammo?

In the middle of a mag during slow fire. After my 10th shot or so I had a double

And I am telling you guys that I know what a f#$kin bump fire is. that isnt what happened. Also.... so frickin sorry about calling it a "slam fire" instead of a "double" sue me.

Oh yeah hot shot? Maybe it'd be different if bumpfire wasn't suggested 3 times!

http://www.usrifleteams.com/forums/i...e&fromsearch=1 April 2009 - 09:10 AM

Posted 22 April 2009 - 11:06 AM

We had at least 2 MIA's over the years at New Holland that had rounds go off when the bolt was closed.
The reason I am able to think of at least 2 is the severe damage to the rifles. In the 2 listed instances the rifles were damaged to the point the receivers were cracked and or broken.
We have an AR-15 do the same thing a time or 2 a year. We have not had rifle damage from the AR-15 slam fires.
My finding at the end of the M1A era and start of the AR-15 era was to completely ensure an AR-15 will not slam fire is to install a light weight firing pin.
Sincerely,
Paul

http://www.thehighroad.org/showthread.php?t=526486

Today, 07:16 AM #4

Hangingrock
Member


Join Date: March 10, 2010
Location: NC
Posts: 152 One time with Federal Match ammunition neither Springfield nor Federal accepted responsibility. The rifle a M1A-Supermatch was examined by Springfield and found by them to be with in specification. I sent Federal the unused portion of the ammunition. They responded per their examination that there were no issues with the ammunition.

Over four plus decades of usage I’ve seen slight firing pin indentations on primers with M1 & M1A rifles. That’s why muzzle direction and safety are so very important.

A competitor on the firing line next to me was single loading his AR15 muzzle down on his shooting stool during off hand. He let the bolt go home and the rifle discharged. It didn’t do the contents of his shooting stool any good at all.

http://www.jouster.com/cgi-bin/reloa...mes;read=31870

saw this same thing happen at all army matches back in 91. the guy next to me had his match m-14 blow up during the rattle battle match at 600 yds.it blew the bolt out of the reciever and pieces of it landed 20-30 yds behind the fireing line. he had one piece go through the top of his cap and graze his scalp and he also bled like a stuck hog.they stopped the match collected all of the ammo, reissued a new lot and away we went with him shooting a different rifle. they decided it was a high primer and this was in LC match. it can happen. it is the only time i ever saw it happen and i have been shooting both 14s and garands for both the USMC and ARMYNG and as a civilian since 1975

Slamfire with Federal Primers in a M1a

17 Aug 2005

http://www.usrifleteams.com/forums/i...pic=4824&st=15

John,

Congrats on your great performance at Perry.

I had to vote "Other". I have just scanned all the posts on this thread so far, but did not see any comment about the primers I use, which are the CCI Mil-Spec primers. I use the CCI 41 in the 223 that I shoot in my AR-15 Space gun (the Space Beast) and the CCI 34 in my 6.5 CHiP wildcat that I shoot in my AR-10 (the Space Monster).

These primers were designed to require 50% more energy to set them off in the standard drop test. To give them this "toughness", they have a slightly thicker cup and a slightly different anvil geometry than regular CCI primers. I was also told by Alan Jones of CCI that the amount and type of priming compound used in them is the same as what is in their magnum primers of the same size, making the CCI 34 and 41 equivalent to the CCI 450 and 250 respectively

I use these primers for one reason: SLAMFIRE PREVENTION!

I have had one slamfire in my shootng career. It happened back in 1990 when I was shooting an M14/M1A and that experience was the basis for the first article I ever wrote for Precision Shooting. Back then, the CCI Mil-Spec primers were not yet available; and after some testing, I switched from using the Federal 210Ms to the Winchester WLR. I have never had another slamfire after that first one, but it was enough. I hung up the M1A in 1993 after legging out and went back to the bolt gun, but when I began playing with the AR-15 Space gun that I call the Space Beast, I immediately started to use the CCI 41s in the ammo for it.

There was a time when these primers were hard to find, I think because of military orders; but now they seem to be more available. I got my most recent batch from Graf & Sons of Mexico, Missouri.

I do use one other primer in my 6.5 CHiP (which is the short 6.5-08 I chambered my AR-10 for), the CCI BR-2, but only for my 600 yard load with the 142 grain SMK. I picked this primer for this load only because loads with it gave me slightly better accuracy than the same loads with the CCI 34 in early testing, and I didn't want to use up a lot of barrel life trying to find a load that would give me slightly smaller groups when I was already getting slightly under 0.5 MoA at 200 yards. At 600 yards, I only shoot these single-loaded. They are never fed from the magazine because I don't like to have the bullets possibly be knocked out of alignment by being bashed into the feed ramps on their way into the chamber.

Just some things to think about.

All the best, Randolph

M1a Slamfire with Federals
http://shootersforum.com/showthread.htm?p=73345

04-20-2004, 04:22 AM
mikej
Beartooth Regular Join Date: Jan 2004
Location: FL
Posts: 441

Yes there are, and CCI makes them for LR and SR applications. I have had slamfires in my M1, M1A and AR-15, but only when using Federal Match primers. They seem to have softer primer cups than WW and CCI. Can't speak as to Remington, never having used them. If you ever have a slamfire it will get your attention, and every one elses as well. It goes without saying, but I'll say it anyway,always keep the muzzle in a safe direction.

http://www.thehighroad.org/showthread.php?t=574351

I would strongly recommend using a small base die and limit reloads 3-4 times. Use LC brass if you can find them. Keep cases trimmed to 2.00 to 2.05. Never use Fed primers. CCI #34 would be best. IMR 4895 is the correct burn rate for operating system. I learned this the hard way. After having a couple of slamfires with my Socom 16. I sent it back to Springfield to replace the bolt and rework the chamber. I believe my slamfires was due to excessive reloading and using a FL die...

M1a slamfires on a reload

http://forum.pafoa.org/ammunition-re...e-reloads.html

April 23rd, 2010
Kramer
Grand Member Join Date: Sep 2007
Location:
Effort, Pennsylvania
(Monroe County)
Posts: 1,178
Rep Power: 366


Re: M1A slam fire on reloads
________________________________________
I saw one blow up on the highpower line back in the early 1990's and it was not a pretty sight.

Anyway it's usually caused by the floating firing pin having too much inertia while the bolt is closing.

To avoid make sure that you feed the rifle from the magazine, the follower will slow down the bolt enough to eliminate this issue.

Also use harder primers like CCI 34 or magnum primers and do not load a round directly into the chamber especially without a mag in place

M1a Slamfire with reload

http://www.marlinowners.com/forums/i...;topic=13587.0


The truth about slam fires
Post by: 4570Lever on June 18, 2006, 11:47:13 PM
________________________________________

I have a had a slam fire in my MIA, which apparently is prone to it.

The effect is like a 2 shot burst full auto, so it was actually kind of cool. Also unexpected, and a bit scary...if the wrong person was nearby i could be accused of having an unregistered full-auto piece, though clear examination would probably show it just needed a gunsmith for repair.

It was nothing I could duplicate effectively, and my guess was and still is that was the cheap, bulk reloaded gun-show ammo I had bought earlier.

I did not think to collect the shells and examine them, and even then could not be sure which I had because they eject all over the place and land in a pile...i was through a box and a half at the time.

notes that came with the gun state that the gun is very sensitively set up regarding headspacing, not sure if that would affect the subject topic.

I dont recall protruding primers, that would have gotten my attention. I imagined the sequence to be, initial round is fired...the bolt comes back and the spent case is ejected while the following round comes up from the mag...at some point the force of the returning bold slams the 2nd round home and force of the bolt slamming home sets off the follow on round...whether the firing pin was stuck forward or the primer was sensitive I will never know.

The incident has not repeated, and this was the rifle used on the doe I took last fall mentioned in full detail here. That was with standard winchester white box ammo.

M1a out of battery slamfire with tight cases

http://www.snipercountry.com/HotTips/Slamfire.htm

M14/M305: I looked at my personal "slam fire" and here is what happend. I have a NM TRW bolt in a Norinco M305, I shot realoads that were made for and previously shot out of my G-3, the local hunting clubs range I shoot at does not allow magazines, or slings,(go figure) to be used.
My conclusion: headspace is really on the tight side after lapping the bolt in, the realoads even though full sized still had the H&K flutes on them and may not have seated all the way in the chamber, I used thin CCI Bench rest primers in tight PMC brass pockets that were seated real flat, and I had to load the round into the chamber and then close the bolt onto it which causes a higher bolt speed forward that if it would feed a round out of the mag. BAM, Slammfire ! Clearly not the Guns fault, but operator failure. The only damage that I found so far is a small deformation in the OP rod cam were the bolts giudewheel runs. I´ll take her to the range again and fire some factory FMJ out of a Magazine to see if the little deburring I did solved the problem.
The straight wall, no neck .308 case is in a special glass case I reserved for little reminders. This case also includes a 1" truck wheel nut and bolt that I stripped. It was stamped L for left hand thread, but in the heat of battle, what do I know.
"Ende"
Torsten <[email protected]>
Germany - Thursday, February 11, 1999 at 08:50:34 (ZULU)

Does someone make an aftermarket firing pin (with spring) for M1 Garands


http://castboolits.gunloads.com/show...ghlight=garand

I've had one slam fire, that was with an M1A. I dropped a round fully into the chamber, then let the bolt fly home. The rifle was pointed at the ground, but I nearly shot the tire on my car. I still have a bunch of 06 ammo loaded with CCI benchrest primers, back when they were still nickle plated, never had a problem with them, once I learned my lesson and knew better than to fully chamber a round. Lot of fellows don't know about slam fires, even a WWII vet friend didn't know what it was, but he understood the mechanics of it when I explained it. So, how was your OAL, Ole? Sticking the bullet into the lands increases the likelyhood of a slam fire, sets the head back every so slightly tighter against the bolt face. But what you've pictured looks pretty normal to me.

M14 Slamfire with NATO ball/Mexican Match

23 June 2012

http://forums.accuratereloading.com/...3/m/7861067471

A very good friend was present and gave the following account based on his observations:

[b]Slamfire in M1a with Federal Primers [b]

http://thefiringline.com/forums/showthread.php?t=461391

Every now and then I used to get a slamfire (mostly Federal 210 match primers) in my loaded M1A. After switching to CCI #34 primers I have had no such problems.

Yesterday, 10:18 PM #6

brmfan
Senior Member

Join Date: October 21, 2008
Posts: 289 Every now and then I used to get a slamfire (mostly Federal 210 match primers) in my loaded M1A. After switching to CCI #34 primers I have had no such problems.





M1a out of battery slamfire with a reload

Harder Primer?
________________________________________

Unclenick,
Would you school me a bit there? Specifically what primer would you consider to be harder.
BTW I shot Hi-power from 1980-1994. I always shot a gun that was built and issued me. Likewise, I shot bullets that came in a lot of little brown boxes with black lettering or white boxes with red and blue writing and they all came in big green cans in wooden crates. During all that time I heard of a slam fire but only actually saw one. That happened on the 600 yd line at Ft Campbell during the Kentucky State Championships. I was scoring a shooter and he had just rolled back in to shooting position after having acknowledged seeing the same score as I on the previous shot. He released the bolt and Blam!!! there was a cloud of grass and dust from under the rifle and I was wondering what the hey? and what is that jacked up black steel thing (magazine opened up like a morning glory). Split the stock and put brass specks in the shooters cheek. I told him- Dude you gonna need another gun?
That may have been a reload but I don't know. Just know I don't want to have one blow.
Thanks for all the input folks
__________________

M1a slamfired out of battery, over long case and CCI #34 primer:

http://www.handloadersbench.com/view...ght=doubledown

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doubledown
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I load alot for the M1A, heres some of the things I have learned along the way. I only use a small base full length dies, I reload on a 1050 Dillon and I also use a full length body die in the tool head just to make sure the brass is properly sized. I also drop every loaded round in a case gauge to make sure it will chamber. (PITA but my face is worth it)

I've had a slam fire ONCE, and on an open bolt rifle like the M1A it was not fun. It was cause by improperly sized brass (and not useing my head) I also use CCI 34 military primers only. The M1a is very hard on brass, I only load my brass twice and then scrap it.

This is what works for me, you can use any dies you want as long as the sized brass fits in a .308 case gauge you are good to go.

I PM’d the gentleman and asked for an expanded explanation:

It was 100% my fault and easily prevented...but I was'nt thinking. I was using CCI #34 primers and Nato brass. My problem was my sizing die backed out on a handful of my reloads, I thought I caught and checked them all but as I found out, One got by. The head of the lone unsized case would not seat fully in the chamber. I SAW THE CASE STICKING OUT OF THE CHAMBER about a 1/2 inch and out of habit let the bolt go home! It seemed like 3 minutes passed as the bolt was headed towards the cartridge and I was calling myself a stupid mother F***er and screwed my eyes shut and waited for detonation. It didn’t disappoint, the receiver grenaded, blew the magazine out and many parts including the rear sight up into the ceiling of the covered range. (I was the only one there) I only had a few scrapes, the rifle needed alot of work to be made operational again. Again, it was my my fault, muscle memory bypassed rational thought, and my lack of quality control. Lesson learned, and most importantly nobody got hurt.

http://m14forum.com/m14/120119-out-b...ire-today.html

Out of Battery Slam Fire Today
________________________________________

After 15 years of shooting and reloading for this rifle, I blew it up this morning. Out of battery slam fire. Receiver came apart to the rear of the rear sight. Bolt is destroyed and op rod is tweaked. Near as I can figure, my once fired LC brass should have been run through a small base sizer, I think the loaded round chambered about 90% of the way, bolt and firing pin wanted to keep going and kaboom. Case head separated and turned into a frag grenade, remainder of case remains stuck in the chamber. Detonation was on par with shooting .50 BMG and taking the hardest punch ever in the face simultaneously.

So what are my options here, complete new rifle? Or some attempt at salvaging the remaining parts that appear to be undamaged on the surface, not a smith so that's why I say on the surface, I have no idea what an event like this does to a barrel and gas system.

http://www.xdtalk.com/forums/m1a-m14...our-story.html

I have had this awful experience with my M1A Supermatch at a Regional High Power Match a number of years ago.....blew up the gun badly and got a face full of tiny shrapnel.

Thank God for good shooting glasses (Zeiss) that were badly damaged saving my vision.

The REAL culprit in this out of battery firing was that the sizing die was not setting the shoulder back properly and the bolt closed JUST enough to allow the firing pin to go forward and KABOOM! One thoroughly destroyed gun and severely shaken shooter...I have pictures if anyone wants...

Shakes you to the core doesn't it?

Randy

PS. It is WELL worth your time and money to invest in a case gauge ( Wilson, Dillon, Forrester) to check your ammo instead of trying to run it through your gun. Would have saved me a VERY costly experience.....

Norinco Poly .308 M305 (M-14) Rifles

http://thefiringline.com/forums/showthread.php?t=561202

Any body else out there with a Poly Norinco M-305? I just witnessed first hand a premature detonation as the rifle was going into battery, throwing the forward part of the round into the breech, and blowing a substantial amount of the bolt head back down the right hand side of the butt, fortunately just to the right of my face. My son was not so lucky, sustaining 14 minor superficial wounds about his face and eyes. My assessment is that the firing pin had somehow become jammed in the forward position, and when it picked the round and started to move it forward into the bore, it fired, well before the round was seated in the bore and it was locked into battery. Before you shoot one of these rifles, I RECOMMEND CAREFULLY INSPECTING THE BOLT AND FIRING PIN SPRING FOR SIGNS OF WEAR, FATIGUE OR DAMAGE PRIOR TO FIRING AGAIN. This rifle was being fired single shot (he forgot the magazine at home) and was on the 21st shot, so it obviously was not a hot gun, and it was factory American Eagle .308 WIN, not a hand load, AND REMEMBER TO USE EYE AND EAR PROTECTION WHEN USING ANY FIREARM TO REDUCE THE CHANCE OF PERSONAL INJURY. After I posted this on Faceplant, another fellow I know posted that a friend of his son experienced the same thing. Unable to verify the age of the rifle/handload/ammo manufacturer yet, but will try. Let me know if anyone else has experienced something similar, or are these isolated incidents?

Thanks, and keep the faith!

Customized M305/M-14 Slamfire...What a mess!

http://www.canadiangunnutz.com/forum...light=slamfire

Short Story - Had an uncontained slam fire in my customized M305/M-14 destroyed the bolt and bent the operating rod. How and where can I get replacement parts?

Longer Story- Customized my M14 with a heavy barrel and custom gas system. Have been working up loads using IVI brass, CCI BR2 primers, Hornady 155 AMAX Moly with Varget and H135 powder. Headed out to my range for a load check. Clean rifle. -8, calm day... perfect! I placed a fouler in the chamber, planning to close the bolt and load a 5 round mag to fire for group. I didn't completely seat the round in the chamber expecting the bolt to seat, as I released the bolt...Boom! Fortunately I was standing above the rifle with the rifle on my bench. The case errupted, the bullet did clear the barrel however most of the case is stuck in the chamber. The bolt detached from the Operating Rod, the extractor was blown off. I recovered the case head, clearly a firing pin indentation. Back in my gun room I stripped the rifle down. Bolt gouged up top and bottom, roller detached and split, roller retainer fractured. Had a hard time removing the Op Rod it was bent outwards and was binding in the groves.

The actual load is irrelavent however I do load the primers deep enough that they are slightly below the case head. I do relieve the trigger springs by dry firing prior to storage. The case does have a firing pin indentation in the primer indicating the firing pin was forward in the bolt. Temperture -8ish..pin frozen? pin bound in place by dry firing? Not sure, could be either.

Now the next issue...I need a new/ replacement Bolt and Operating Rod. Are these parts readily available and from where? Will headspace be an issue with a different bolt? I have a stock Polytech M305 from which I could "borrow" the parts to finish my load development but I don't want 2 unservicable rifles. I was/am planning to post the build and developement when finished load developement.


Slam Fire's "R" US. You are lucky you have both eyes my friend. Safety Glasses will usually prevent most eye injuries.

Just before too many rant over the Norinco M-14's, there are alot of semi-autos that both commercial and military that can slam fire not just the M-14, when allowing that powerful recoil spring to accelerate the bolt from zero to 60 in 5.2M/secs. Just last week-end a friend at work witnessed a Remington 742 .30-06 slamfire. The kid carrying it forgot the magazine for it way back at camp and it was not much time left for the evening hunt. He said oh well, just one in the chamber will do. Turned away from my friend, let her fly on a chambered round and KABOOOM!. Hit a granite rock 3 feet from muzzle, peppered his jacket and face with sharpnel leaving it bleeding quite bad. My friend was just covered in granite dust. The kid refused to go to the emergency, how do you explain a firearms accident,... so he sucked it up.

They returned immediately home, and the kids father who owned the 742, said well that will never happen to anyone again and proceeded to the garage where he cut her down in 2" strips. My friend keep telling him the 742 needs to be loaded from the mag but he chopped her to scrap!

[condor bravo]

I hope I'm not responsible for creating all this fuss by innocently mentioning slamfires back in post #4. But not likely, it would have developed anyway. The thread has been informative and should be appreciated. Keep the ball rolling without the sarcasm. What I initially thought might have been four second shot slamfires, U'nick pointed out where they were probably just doubles and explained how that can happen with a loose sling.

[Unclenick]

Originally Posted by schmelba99

I'm apparently lucky that the rounds I have shot thus far have not killed me or blown up my gun.

Technically that's correct. It's true for every round you fire in any gun, though, at least in some small degree. We had a member at The Shooter's Forum who had fired many tens of thousands of rounds of commercial handgun ammunition doing evaluation testing for government agencies. He pointed out that if you fire enough factory ammunition you eventually see examples of every kind of error a handloader might ever make, plus a few a handloader is unlikely to make. Hot loads, no-powder loads, no-primer loads, inverted primer insertion, plus cases with no flash hole or a seated bullet jacket with no lead core in it. So it takes luck, but just doesn't require a lot not to have these problems in your personal experience, given the smaller volume of ammunition the average shooter puts down range.

I know that it is psychologically difficult to accept that one's personal experience of zero problems doesn't prove anything more than that it's possible to have such an experience. Thank goodness, most do. I also know most people driving GM cars with the faulty ignition switch never had a problem, either. Does that mean that if you have one of these cars you will ignore the recall and not spend the time and gas it takes to get it to an authorized repair center to be replaced? Would you let your kids drive it unfixed? No. You maximize your odds and your kid's odds because it is cheap and simple to do.

What may be missing here, is a quantification of how much luck is required to stay safe while ignoring advice to optimize your chances of avoiding a problem. In the Garand, specifically, at the match I mentioned where a round of LC ammo slamfired, there was just that one incident. We had 500 participants in 4 relays at Perry's Viale Range shooting the 50 round National Match course. That's 25,000 rounds put downrange, enough to shoot out 5 barrels on a single gun, and yet only one incident. If you haven't shot 25,000 rounds of M2 Ball in Garands, you still haven't given yourself an even chance to experience the problem, and it probably takes more than that if the gun is in good shape.

It is also important to point out the gun that had the slamfire was pulled off the line right after it happened, of course, and a substitute was put in. So that gun didn't get a chance to repeat that behavior and was set aside so military team armorers could check it when they came in for the National Matches later that year. They have the proper gauging tools, of course. Whether or not it turned out the gun was at fault or the round was defective, I don't know.

I've seen up to 3 slamfires at large matches, and I've seen none at all at others. This was during the Garand and M1A era of service rifle match shooting. I don't believe I've ever been present for an AR slamfire, likely for the reasons mentioned in Slamfire's post. And all the slamfires I've been present for except that one round of LC ammo, have always been with handloads. Member Hummer70 says he's looked at the ammo every time there's been a slamfire at a match he's attended, and thus far has always found high primers among the shooter's remaining ammunition. So, high primers are most often the cause—just not always. Bottom line, though, even with handloads, on average, I would guess from what I've been present for that one chance in twenty-thousand rounds is probably in the ballpark for the slamfire rate with those guns. But that doesn't segregate the rate of issues with the guns from the rate of issues with sloppy handloading.

So that's the situation. You have to shoot a lot, or the odds are you won't see a problem. It's just that for some unlucky individuals, the odds don't play out.

Slamfire is correct about the Garand and M14 mechanisms. They both depend on the base of the cartridge case being push fed by the extractor to keep the primer away from the firing pin during stripping a round from the clip and feeding it into the chamber. It then snaps over the rim as the bolt closes, during which time the receiver "safety" bridge blocks the firing pin until that operation is complete. In an OOB fire, the extractor somehow snaps over the rim of the case before the bolt closes. It takes the round's feed meeting some kind of resistance for that to happen. The broken case I suggested is just one possible cause of that. You can avoid that cause by inspecting cases properly, annealing them periodically, or just retiring the brass after four or five reloadings, as John Feamster used to recommend doing.

As to the small base dies, you can tell by measuring whether or not standard dies are adequate. My best guess is that it is difficult to find an example of a standard die failing to adequately resize cases fired in your own chamber unless it is very tight. It's the odd fat boy from another gun getting past you that is the main concern, and if your chamber is fat or loose, even that won't be an issue. Every once in awhile we get an AR owner reporting inadequate feed reliability if they don't use a small base die. Presumably the odd Garand or M14/M1A is like that, too. For that reason, I would not ignore feed failures in these weapons. You want to find the cause and cure so you don't have slamfire or OOB fire issues.

[Slamfire]

I don't believe I've ever been present for an AR slamfire, likely for the reasons mentioned in Slamfire's post. And all the slamfires I've been present for except that one round of LC ammo, have always been with handloads.

AR15’s slamfire. They slamfire in battery, I met a credible source who claimed witnessing an out of battery slamfire, with Government M4’s, firing federal Gold Medal match. I have no idea how that could have happened. This appears to be an out of battery AR15 slamfire, the shooter was using factory ammunition, it is very puzzling https://forums.1911forum.com/showthread.php?t=423194

I have not heard of any other out of battery slamfires in AR's and of the ones I have heard, I don't know how it could happen. I have had, seen another, and heard of in battery slamfires.

Mine occurred during the NRA standing slowfire stage of a highpower match. I was using the brass colored WSR primers. Winchester nickle primers used to be the primer I preferred to use, never had an issue, but these brass colored WSR are thin and pierce easy. My AR also slamfired, in battery.

The bud with whom I was squadded, his AR slamfired with a Federal primer, during his standing relay. Years later, he had another AR15 slamfire with Federal primers during the standing stage and stopped using them.

What characterizes the standing stage from all other stages is that the rifle is loaded single shot while standing. (That you shoot the standing stage while standing ought to be obvious from the name.) However because you are standing, most people lower the muzzle, drop the round in the chamber, and hit the bolt release while the muzzle is down. Enough slamfires occur standing that it has become evident that the little extra bolt acceleration due to gravity is enough to set off the occasional primer.

The NRA banned loading on the stool. I used to see shooters balancing their muzzles on their shooting stool, drop a round, hit the bolt release. I will bet someone’s rifle slamfired through the stool and that is why it is now illegal to load on the stool. I can just imagine the consternation on the line when some poor schmuck blew out the bottom of his shooting stool with all his equipment inside. I hope no one shot their foot. A 223 round in the foot would cause a nasty wound.

I have stopped dropping the bolt on a round in the chamber, I put a round in the chamber and lower the bolt half way before letting go. I also do this with the rifle sort of level.

You will get DQ'd if your round lands in front of the firing line. I want whatever future AR slamfires I might have to hit the berm. Loosing 10 points is better than having to go home.

I also use CCI #41 primers as they have thick cups and are hard to pierce. These are excellent primers in the AR and I shoot HM scores (seldom HM standing scores anymore) all the way out to 600 yards with the things.

My recommendation, always feed rounds from the magazine to slow the bolt, if you drop a round in the chamber, lower the bolt half way before letting go.

Member Hummer70 says he's looked at the ammo every time there's been a slamfire at a match he's attended, and thus far has always found high primers among the shooter's remaining ammunition. So, high primers are most often the cause—just not always.

I don’t see how high primers can ignite unless the primer is seated in a shallow pocket. For a primer to ignite, the anvil has to be firmly set and the anvil/primer gap cup set. As CCI has said, and as many posts have shown, high primers are the most common cause of misfires. I am of the opinion the high primer cause is basically a red herring, a misdirection. One poster related in battery slamfires he had in a AR10. He had removed the crimp on military ammunition, but left the brass donuts in the bottom of the pocket. By putting spacers into his primer pockets, he created the conditions for a firmly set anvil and setting the anvil tip/primer cake gap.

Just to unsettle people, here is a list of slamfires, some out of battery, in rifles other than Garands, M1a’s, or AR15’s.


Slamfire in DPMS 308

http://www.thehighroad.org/showthread.php?t=467039

I had a slam fire once in my DPMS with regular primer reloads. I have since switched to mil spec primers or magnum primers for my auto rifle reloads. I also use the Lee factory crimp on all reloads for my autos. Kinda had to double up on supplies because I use bushing dies and match primers for my bolt guns in .308 and .223. I like to keep my brass separate too because I want to just neck size for the bolt guns and full size for the autos.

It was my .308. I was using some match primers because that was all I had at the time. I did fire up about 60 other rounds that day without incident.

http://m14forum.com/ammunition/10127...mer-m14-2.html

07-30-2011, 07:41 PM
hagar the horrible
Joined: Feb 2007
From: Columbia, SC
Posts: 291

I have never seen a slamfire with a Garand or M1A, but I have seen plenty with AR'15s, and in every single case it was a winchester primer, or the shooter did not know. I make it a point to ask. Had a friend in AZ that got a slamfire, no damage to the rifle, warned him about using winchester primers, and a couple of weeks later he got another one, this time damaging the rifle pretty bad. He switched to Remington 7.5's after that..

20 Feb 2008 Shotgun News,
Article “ Micro Galil, The Ultimate Krinkov”
Author Peter Kokalis
Page 12

“Most Kalashnikovs have inertia firing pins, without an associated spring. The initial lot of Galils brought into this country by Magnum Research INC. also had no firing pin springs. The Micro Galils that I examined in El Salvador were not equipped with spring-loaded firing pins either.

Military small arms ammunition primers usually have relatively hard cups, which are not easily touched off. American commercial cal .223 Rem ammunition, including Winchester ammunition often features fairly soft primer cups. In 1983, Winchester ammunition in particular caused several slam-fires and all Galils offered for sale in the United States were quickly retrofitted with strong firing pin strings. “

29 August 2007

CENTURY INTERNATIONAL ARMS, INC.
236 Bryce Boulevard
Fairfax, Vermont, U.S.A. 05454
Tel: (802) 527-1252 Fax: (802) 527-5631
Date: August 29, 2007
Subject: Galil and/or Golani Semi-Auto Sporter Rifle

We are requesting that customers who purchased the Galil and/or Golani Semi-Auto
Sporter that have serial numbers between GAL00001 and GAL02393 send in their
firearm to us as we have modified the bolt and are installing a new firing pin and firing
pin spring to ensure that your Golani offers you the utmost safety and reliability. All Galil
and/or Golani rifles that have the letter "F" or "X" on the bottom of the receiver front cut
off have already been upgraded and your rifle does not need to be sent in to us.If you
are a dealer, please provide us with the names, addresses and contact information of
the purchasers of these Galil/Golani rifles. We will contact them directly. If you are
contacted by these customers, please have them call us at 1-800-270-2767 to obtain a
return authorization. We appreciate your cooperation in this matter and hope to have
this situation resolved as quickly as possible




http://www.xdtalk.com/forums/ak-47-t...-question.html

AK slam fire question

11-05-2008 Hi guys

I thought I would throw this out there to see what you guys think might be causing a slam fire with my AK.

I took my Romy G to the local range to sight her in. I loaded up the mag with 3 rounds each time 40 rounds total. On two occasions after I fired the first shot the second went off right away. I can only describe this as a slam fire. It seems that when I fired a round something happened when chambering the new round and caused the second one to go off without pulling the trigger. I was using Winchester
White Box 7.62x39 (local range doesn’t allow wolf which is of course what I have plenty of)

11-10-2008

So I cleaned it all up and checked over the FCG real close and everything seems to be in working order. I am not getting the "hammer follow" issue. The disconnector is retaining the hammer when the trigger is fully depressed. And the trigger hook is is grabbing the front of the hammer.

I also took the bolt down and cleaned it up real nice.

I took it to the range over the weekend and put about 90 rounds of wolf down range and not a single issue. Nothing that resembled what happend when using the Winchseter ammo. I did check one of the rounds that were chambered to see if there were any marks on the primer and there was but it didnt go off.

http://www.thehighroad.org/showthrea...44#post6193244

AK47 Saiga Slamfire

I have a Russian Saiga 7.62x39 That I love more than anything to shoot. The other day I took it and a few hand guns to the range (in door) The weekend before I picked up 700 rounds of the military ammo at the gun show Boy did I have a rude awakening. Slipped in a 30 round mag, dropped the bolt and un loaded 30 rounds without a miss fire. You have no idea how quiet it got there. I had the range officer on me so fast. After a lot of wounderment we found the problem. The primers in the military loads are soft. I have seen that happen in the SKS but never in an AK. I guess I wanted to share this adventure with everyone and a warning. With the range dude there I loaded up a 5 round with this ammo and it did it again. I then re loaded the 5 round mag with some Wolf 122gr. HP Steel Case and everything went back to normal. Just wanted to share this miss hap and be sure where your muzzle is pointing when you lock and load.

They came loose in a can which my brother has. I will contact him and tell you just what is was. I do think I remember that there were 500 Rounds military Surplus. Egyptian

http://www.canadiangunnutz.com/forum...re#post8841078

Very clean SKS that slamfired?
Hi all,

So picked up an SKS from wholesale the other week, stripped and cleaned the entire thing (including bolt), shot 20 rounds of PPV out of it the other day with no problem, cleaned it; then today I shot 10 rounds of federal ammo and had a slam fire on the last second clip. This was pretty scary for me because the FP was clean and moves freely in the bolt. Do you think it could be an issue with the ammo having sensitive primers?

http://www.thehighroad.org/showthrea...49#post7180249

Browning Automatic Rifle (BAR) Slamfire in 270 Win. Neck sized cases.

It's good to think you had the good common horse sense to ask that question. Some have assumed nothing is any different since the cartridge is what it is, 30-06 or what ever high powered rifle round, and then necked it as with their bolt actions. A man came into the gun shot I worked in with a really nice, well was a really nice Browning semi auto, I think it was chambered in 270 win., no matter. He said he had been necking for a while for that rifle without problems. I doubt he considered now and then chambering issues as problems. Either way, all it took was one slam fire to ruin his day and rifle, and fortunately not his life!

http://www.thehighroad.org/showpost....06&postcount=4

Thread: Anybody know why "they"advise against .308 for M1A
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Today, 09:48 AM #4

Hatterasguy
Member


Join Date: January 4, 2010
Posts: 670

I recently had a slamfire issue on my FN49 and I suspect it was casued by using commercial .308. I have yet to take it back to the range to confirm.
__________________
"Those who are allowed to shoot are those who are prepared to be shot."
Lelouch Vi Britannia

Out of Battery Slamfire in FN49

http://thefiringline.com/forums/showthread.php?t=543905

Hey all,
I recently had an 'out of battery slamfire' in my, two piece firing pin, FN49. I had made 8mm Mauser ammo from milsurp 30-06 cases. The dimensions of the cases (30-06 and 7.92x57mm S) are identical at the base and only need to be cut down to the correct length, sized and trimmed. The problem with making your own ammo for the FN49 is that it is a very robust firing mechanism that will ignite a sensitive primer before the round is seated in the chamber. I was using CCI 200 Large Rifle Primers which are reasonably sensitive for bolt action rifles and, I have found out, too sensitive for semi auto rifles. Even though I've used these primers for years in my FALs, and WASR AK47, I'm going to stop and use CCI 34 Large, 41 Small, or milsurp in the semi auto rifles.

The 'oob' slamfire caused the receiver and bolt carrier to become a bad fit! I searched (Google) and found a gunsmith in Missouri who could fix the rifle. His name is Guy Snelen at AMG International in Humansville, Missouri. He repaired it, test fired it, and sent it home to me. If anyone needs a good gunsmith, get in touch with Guy.

Kaboomed 8mm Egyptian FN-49 .... Now A Floorlamp!!!!

http://www.sksboards.com/smf/index.php?topic=132165.0
« on: July 03, 2014, 06:26:50 PM »

My LGS gave me this Kaboomed Egyptian FN-49 today. It's a CAI gun. To add insult to injury it was the second time it had kaboomed. The owner had it "fixed" and then it let loose again after a few rounds. I think I would have quit the first go-round.

The funny thing is when I took it apart I could not find any reason it let go unless it fired out of battery. The gas setting was fine. The only broken part was the rear of the extractor when the kaboom bent it out and cracked it.

When it let go (8mm Romanian surplus) it looks like all the force went straight down and bulged the mag and in turn stretched the sides of the mag well in the trigger group/guard assembly. I got the mag pounded back in shape and bent in the sides of the mag well opening true.

One thing I did notice was that the stock was repaired poorly after it let loose the first time. It would not have taken but a few rounds to have split it again. It is one of those beech CAI replacement stocks and it split darn near perfectly in half.

I could fix the stock but why bother, I'd never-ever trust the rifle. The guy got away twice with nothing but hurt feel-goods and a lighter wallet and I don't want to be the odd man out with a injury.

I was thinking of parting it out or selling it as is but I think I might make a gun lamp out of it instead to preclude anyone getting bad parts or crazy ideas of trying to shoot it.

I glued/screwed the stock back together well enough to start making a lamp of it. It will be real easy to do.

http://www.thehighroad.org/showthrea...r+info+Request

http://web.archive.org/web/200605060...ch/sainfo.html

These articles were available on-line, but the links are dead, so I copied
my post from an other board (two posts here as we are limited to 20000 characters):

Disclaimer: This article contains information that may not be appropriate for your particular firearm. Consult your gunsmith in regards to the safety of firing your particular firearm. Consult your reloading manuals for all safety procedures when reloading ammunition. We are not responsible for typographic errors. Your mileage may vary.

What follows is a reproduction of an article from Handloading Magazine on the 7.5x54 MAS, prefaced with comments by myself, updating the magazine article with considerations for the MAS semi-auto rifles.

Update: Reloading the 7.5x54 MAS.
By Paul Pelfrey

While the reprinted article that follows is essentially accurate, the author did not take into consideration the availability of the various semi-auto French rifles that would later be on the market at an affordable price. This article should be applicable to the MAS-44, MAS-49 and the recently imported MAS-49/56 rifles. With the data in table II of the article below, I didn’t need to reinvent the wheel to start my experimentation. My load was the 150 grain Sierra FMJ spitzer, loaded on Norma brass, with Winchester WLR primers, packed with 44 grains of AA-2520 powder. I had had a good experience with this load through my MAS-36 bolt action rifle and decided to give it a go in the MAS-49/56. The MAS-49/56 I had acquired came from SOG and was still in the arsenal wrapping when I received it. After a thorough cleaning I took it and 50 rounds of my handloads. I first test fired the rifle with some surplus Syrian ammo I had. I was disappointed. The Syrian ammo was rife with hangfires and dead primers, and those rounds that did fire would not actuate the bolt properly. Most of the rounds stovepiped none ejected fully. I then took my handloads, loading a single round in the magazine at a time and easing the bolt forward. To my delight, the rounds were rather accurate, keeping inside 1.5 inches at 50 yards, and the brass ejected cleanly. After 10 shots loaded one at a time I loaded two rounds. This time, I let the bolt fly forward on it's own to chamber the first round. The round immediately slamfired as the bolt closed, and the second round chambered. My finger had been outside the trigger guard. I unloaded the gun, then reloaded two rounds. This time, the round did not fire when chambered. However, when I pulled the trigger, the rifle fired both rounds in rapid succession. My first thought was that this was a repeat of a phenomenon that I had experienced with an SKS carbine. In that case, the modern lube I had used on the SKS was too slippery and allowed the firing pin to travel forward with the bolt actuation with sufficient inertia to impact and detonate the primer. In that case, removal of the lubrication solved the problem. I disassembled the MAS rifle and dried the components completely and reassembled it. The slamfire problem persisted. My attention turned to the handloads. Checking the primer seating depth and dimensions of the case turned up nothing out of spec (except the smaller rim diameter, per the Handloader article). I then chambered a Syrian round and then removed it. Examining the Syrian round showed a slight indentation on the primer. I then left the range to ponder my next move.

Next weekend I returned with more handloads, this time using CCI regular and match primers, and Remington primers. During this session my handloads still suffered from slamfires while the military French and Syrian ammo did not. Conclusion: Commercial primers are too thin to operate safely in the French MAS semi-auto rifles.

Solution: CCI, under the name of their parent company, Blount, manufactures a military spec primer. I found a brick at a gunshow in a plain white box. The label read "1000 M-34 Primer for 7.62mm Cartridge". Loading 50 more rounds with these primers solved the problem. Not a single slamfire. Most distributors do not carry this primer, and will only order and sell it in a case lot (5000 primers). The good news is that these primers sell for only about $6-$9 more than the same quantity of regular primers. I would recommend their use in any round that might be loaded in a semi-auto rifle, just for an added margin of safety.

Reloading this round has become much cheaper since the publication of the Handloader article. Lee now makes the dies for this round, and I have seen a retail store price on them for $29.99 (half of RCBS). After talking to the techs at Lee, they are willing to make a tapered expander for necking up the Swedish brass for $15, and if you send them a formed cased with a bullet (no primer, no powder) they will make one of their Factory Crimp Dies for it for $25. I recommend this, inasmuch as a few of my handloads had a problem with the bullets being pushed back into the case upon chambering. This can lead to overpressure and possible injury. Brass is more plentiful now as well. I find Remington 6.5 Swedish at shows for $27/100 and Kengs in Georgia also stocks Lapua 6.5 Swedish for a similar price.

.


http://thefiringline.com/forums/show...=425509&page=2

Tamara
Moderator Emeritus

Join Date: March 11, 2000
Location: Indianapolis, IN
Posts: 15,880

Originally Posted by B. Lahey

The Prvi was the only ammo I could find, and it seems to get good reviews from MAS 49/56 owners, but I also found one complaint of a slam-fire with it.
The MAS-49 has a massive firing pin to make sure it pops hard military primers. Slamfires are not uncommon with commercial Prvi or FNM ammo. Mine gave Oleg Volk a pretty spectacular bruise on his right thumb with the bolt handle when he chambered a round.

Titanium firing pins were available for a time, but I haven't seen any for a while. Others have reported success in lightening the original FP.

I'd put one round in the mag the first time you let the bolt fly, just in case...
__________________
MOLON LABE!

I don't know a single semi auto rifle design with a captive firing pin. Pistol mechanisms have firing pin blocks, don't know of a rifle with one. Therefore all semi auto mechanisms have free floating firing pins. Because of this, it is my opinion, you want to use the least sensitive primer you can. Commercial primers have gotten ultra sensitive because shooters complain about the round not going off. You find lots of threads on this, and what is blamed, is not the ancient mainsprings in the boom stick, but the primer. Sometimes the ignition mechanism is so inadequate that certain brands of commercial primers won’t ignite, which leads to that manufacturer reacting to the market by making their primers more sensitive. Just before 2000, Winchester made their primer more sensitive, including their rifle primers.

To hammer on the ideologues at the CMP, they are preaching that only high primers and your worn out receiver bridge cause slamfires. They will not and do not acknowledge that the root cause for 99.99% of slamfires is a sensitive primer whacked by a free floating firing pin. Decades previous, the Army and the NRA claimed the only causes of slamfires were high primers and worn receiver bridges and that is nonsense. These guys are so out of touch with reality, they probably believe the nonsense they preach. If you really look at what they are preaching, the only causes of slamfires are shooter misconduct, they totally ignore the action design. In their delusional universe the Garand mechanism is perfect. Well it is not and was not. The only semi auto’s on the firing line decades ago (in quantity) were Garands and M1a’s, so shooters did not have a basis of comparison with other mechanisms. Look at the reports of slamfires in other mechanisms, mechanisms that are totally different from the Garand, no receiver bridge for one thing, any yet, they slamfire with factory ammunition. Which, presumably, won’t have high primers. There are plenty of accounts of slamfires in mechanisms where the reloader explicitly said the primers were below the case head.

If the high primer only theory is correct, then neck sizing is fine for semi auto rifles. So is using the most sensitive primers, like pistol primers for cast bullet loads. There are probably some other dangerous practices that fall out, and have hurt shooters, destroyed rifles, because of the lies of these types.

[schmellba99]

Technically that's correct. It's true for every round you fire in any gun, though, at least in some small degree.

I understand that, trust me I do.

My post was made a lot more tongue-in-cheek with respect that there are times, and members, that seem to go overboard on some things regarding reloading.

For example - on this thread, if I were a newbie getting into reloading for the Garand I found in Grampa's closet, I'd read slamfire's post and then say "eff it, no way am I going to reload for this rifle because I"m not going to spend that much time and effort on tools, precision equipment, custom cut chamber gauges that I need to measure every round, electron microscope scanners to verify that my primers are seated perfectly at .000728874" below the face of the case head, etc. etc. etc."

Just like reading (or attempting to discern what is being said anyway) in one of F. Guffey's posts - if I were getting into the reloading world and used him as a guide for what needs to be done, I'd quit before I started simply because not every single person needs to know what the bore diameter is of his rifle barrel at 7.9927847220984" away from the end of the chamber is, or what the land diameter is so that we can custom cut our own dies and turn our own projectile to be within .0000001" of land diameter so that we may have a chance at having a proper projectile to bore fit and hope we may be able to squeeze some type of acceptable accuracy out of that particular rifle.

Same with the tube fed primer thread.

There are just times and subjects that get so far off into the twilight zone of the 1:50,000 chance something may happen that it begins to become comical, and honestly I think counter productive to conveying good information. And sometimes posters just have to be "right", come hell or high water.

I think slamfire, to use this thread as an example, posted good information about something to keep in the back of your mind when loading for a Garand or M1A (or the 32 other types of rifles he posted slamfires about), don't get me wrong. But anybody looking for practical information on reloading for a Garand is likely to be absolutely paranoid of doing so after reading his posts.

We all know shooting and reloading is not without peril; it is inherent due to the very nature of the mechanical equipment an chemical reactions necessary to send that projectile down the barrel at 3k feet per second. No need to overplay the danger, IMO.

[mehavey]

Slamfire's post (as he intended):
~~~~~ DISPELL BAD INFO -- IDENTIFY DISCIPLINE/SOLUTIONS ~~~~~

- There are out-off battery slamfires in the Garand design (both M1 and M1A)

- These slamfires are primer related (both in seating and in sensitivity)

- These slamfires are exacerbated by (a) case resistance to freely seating on closure, and (b) free-bolt speed in the absence of resistance from stripping a magazine round.



Like anything else in life, these three things can be mitigated against very effectively:

- SB size the cases (insurance)
- Use CCI/mil-spec primers (insurance)
- Hand prime to ensure proper seating (discipline)
- Don't let the bolt freely slam home on an already-seating cartridge (discipline)

Simple.

[1stmar]

I agree. I am certainly revisiting my reloading techniques for my garands and M1A. I feel as though I have been lucky to not have had a slamfire.

If you go back and look at the history of the M16, there were countless reports of issues with the first model's hence the forward assist etc.. I am surprised that I have never heard of slamfires being a chronic concerns for M1's in combat, given the extreme opportunity I would have thought there would have been more awareness or enhancements to address.

[Unclenick]

Originally Posted by Slamfire

I don’t see how high primers can ignite unless the primer is seated in a shallow pocket.

I think it's probably a complex dynamic interaction. A high primer in a revolver or a bolt rifle pretty much only has the firing pin pushing forward on it. In the Garand and M14 mechanisms, the case shoulder get shoved pretty hard forward by the extractor so I expect it rebounds some when the extractor snaps past the rim and into the extractor groove of the case. You then end up with a poorly supported primer that is more deeply indented by the firing pin than would be the case with a properly seated primer, and then the case rebounding against the bolt face and tending to seat the primer at least flush with the head and perhaps shoving the anvil reward before the firing pin bounces back as well. This is just speculation on my part, but assuming the pattern Hummer70 has observed is a valid one, I expect some dynamic like that is involved.

The CCI #41, CCI told me ove the phone, is identical to the CCI 450 in both cup and priming mix, except they use wider angle anvil legs to achieve the military sensitivity numbers. Federal, on the other hand, has their new (relatively) GMM205MAR, which they told me by email is identical to the 205M except that in their case they did make the cup thicker to get it down to military sensitivity spec.


Schmellba99,

An issue has been a number of persons (the CMP bulletin board, in particular, seems to attract them) who just flatly deny any problem like an OOB fire can ever happen in a Garand under any circumstance because they, personally, don't see how it could happen. And they seem to make a point of telling every newbie so and contradicting good advice to minimize the chance of it occurring. These individuals take advantage of the fact these events are rare enough that they can get away with spreading misinformation about them and not see too many people disagree with them.

As I explained, the amount of luck you need to avoid the issues described is not huge. Many have gotten away with being sloppy in their loading practices. And for myself, I'm not overly concerned about the personal risk but feel obliged not to subject the fellow on the next firing point to even a small risk I can so easily mitigate. It's just a matter of the usual warnings not to treat handloading in a cavalier fashion by taking on some extra weight and some extra considerations in floating firing pin self-loaders.

[schmellba99]

feel obliged not to subject the fellow on the next firing point to even a small risk I can so easily mitigate. It's just a matter of the usual warnings not to treat handloading in a cavalier fashion taking on some extra weight and some extra considerations in floating firing pin self-loaders.

Nothing wrong with that at all - we pretty much do that on every thread in one form or fashion as it is.

But there is a bit of a difference between mentioning a particular action could possibly happen (in this case, a slam fire) and writing a dissertation that essentially states that if you don't have these specific tools and do these specific things and ensure that these specific measurements are adhered to, you'll have a slam fire with your gun and it will be all your fault.

I'd like to think that anybody with an nth of common sense would realize that with any semi-auto weapon, slam fires are a distinct possibility - whether from the gun or the ammo. Seems inherent that the possibility is there to me because of the very nature of the operation.

[Slamfire]

Slamfire's post (as he intended):
~~~~~ DISPELL BAD INFO -- IDENTIFY DISCIPLINE/SOLUTIONS ~~~~~

- There are out-off battery slamfires in the Garand design (both M1 and M1A)

- These slamfires are primer related (both in seating and in sensitivity)

- These slamfires are exacerbated by (a) case resistance to freely seating on closure, and (b) free-bolt speed in the absence of resistance from stripping a magazine round.

Like anything else in life, these three things can be mitigated against very effectively:

- SB size the cases (insurance)
- Use CCI/mil-spec primers (insurance)
- Hand prime to ensure proper seating (discipline)
- Don't let the bolt freely slam home on an already-seating cartridge (discipline)

I like it! Much more concise than my ranting and raving.

If you go back and look at the history of the M16, there were countless reports of issues with the first model's hence the forward assist etc.. I am surprised that I have never heard of slamfires being a chronic concerns for M1's in combat, given the extreme opportunity I would have thought there would have been more awareness or enhancements to address.

A history lesson of a sort, the early M1 Garand had a round firing pin exactly like the round M1 carbine firing pin. These are pictures of the rare early round firing pins, when Orion 7 had them, they sold out their inventory at $100.00 apiece!






It is obvious the Army experienced slamfires in early Garands because later firing pins were scalloped to reduce weight. On top is the Garand firing pin, the middle the M14, and the bottom a M1 Carbine firing pin.




Since this was so long ago, and there are no records, we don't know all that went on behind the scenes. As the Army did for the M16, they could have made the primer less sensitive, but they could not have made it too insensitive because that would have caused misfires in other mechanisms which used the 30-06 cartridge. The simplest solution was to reduce the kinetic impact energy of the Garand firing pin by reducing its weight. Which is something that was also done for the M16. This was not necessary for the M1 carbine, so they kept the relatively simple to make but heavy, round firing pin. To accommodate this heavy firing pin, the M1 carbine primer spec is a very insensitive primer.

The history of the #41 primer is different and came about due to slamfires in the early M16’s.


http://www.dtic.mil/dtic/

Report of the M16 Rifle Review Panel. Volume 5, Appendix 4. Ammunition Development Program

Primer Sensitivity

Initial Specifications. Ammunition specifications established by the Air Force on 24 January 1963 provided for quality control against cocked, inverted, loose, and nicked primers. The specifications further provided for inspection and test of waterproofing and the crimp of primers. However, the specifications did not provide for specific limitations on primer sensitivity for 5.56mm ammunition.-

Development. At the first meeting of the Technical Coordinating Committee on 26 March 1963,16 / the Air Force representatives submitted a list of reported ammunition deficiencies, which included "high primers" and "primers too sensitive". It was agreed that Frankford Arsenal would investigate the matter and recommend corrective action.

One of the malfunctions reported by the Air Force was the premature firing of cartridges that occurred upon initial charging of the M16 rifle with a cartridge from the magazine, or upon singleloading of a cartridge directly into the chamber, or when two rounds were fired at one trigger pull during semiautomatic fire.

This malfunction was attributed to "high" or protruding primers, although the tests did not confirm this theory..

However, analysis indicates that if high primers caused the premature firing, the firing should have occurred upon impact of the bolt face with the protruding primer. At this point in the weapon cycle, the bolt head would not. have been rotated to the locked position by action of the cam pin and carrier. Had firing occurred with the bolt in the unlocked position, it would have resulted in a blow back and would not have been undetected. No such disruptions were reported-. Since premature firing occurred after bolt-locking, it must have coincided in time with the impact of the bolt carrier against the bolt head. At the instant of impact, the "free floating" firing pin is moving at the velocity of the bolt carrier. The kinetic energy of the pin must be dissipated by such frictional forces as it encounters in the forward movement, and, finally, in impact of the firing pin tip with the primer of the chambered cartridge. This premise was confirmed by the visible indentation appearing on cartridges which were chambered by the mechanism and extracted unfired.

Frankford Arsenal identified test procedures for measuring firing pin energy and recommended limits for primer sensitivity.

Remington Arms Company, on the basis of the information contained in the Frankford Arsenal First Memo Report, undertook the design of a new primer that would be less sensitive and less susceptible to the inadvertent energy delivered to the primer by the free-floating firing pin of the AR15 rifle. Since it is difficult to adjust primer sensitivity by chemical changes, Remington elected to accomplish the desensitization" by increasing the mechanical strength of the brass primer cup, which must be indented by the firing pin to cause ignition.

As a result of the decision of the Commanding General, USAIIC, to modify the rifle, Colt's Inc. developed two designs, a linear spring device and a cam pin friction device, to reduce firing pin energy on bolt closure. These two designs were tested by the Air Force conclusions of this test were that both devices effectively reduced firing pin energy; however, the Air Force recommended against their adoption because they increased the probability of a misfire (although no failures to fire were identified in the test results), added to the cost of the weapon, and adversely affected its reliability. Army tests of these devices indicated that the linear - ~spring friction device was a satisfactory solution; however, at the Technical Coordinating Committee meeting of 10 December 1963, at which a comparison of all tests done by the Army, Air Force, and Colt's Inc. was made, the committee agreed to adopt a modified lighter firing pin, which was used in the cam friction device and was recommended by Colt's as a solution to the problem..

So, to reduce slamfire rates in the M16 the Army did two things: 1) it reduced firing pin weight, and 2) required the use of less sensitive primer, the #41 primer.



The heavy original M16 firing pin on top.

[Jimro]

Funny you should mention the M16.

For a floating firing pin to impact a primer before the bolt is in an in battery position on the M16, or for the M1/M1A for that matter, the extractor has to snap over the rim of the cartridge.

Then either the firing pin has to be jammed forward by gunk, or have enough inertia to set off the primer.

The M16 bolt design being what it is, makes it impossible to have the firing pin protrude without the bolt being cammed inside the bolt carrier group, which is something the M1/M1A does not have. In the M16 the shoulder at the rear of the firing pin stops against the BCG until the bolt is pushed back and cammed over so that the end of the bolt is what stops forward movement of the pin.

For an M16 to have a total out of battery slam fire, the bolt can't get bound up in the "star chamber" area, it has to be fully in or fully out, but fully out can be tricky because the cam pin binds against the inner surface of the upper receiver.

So all this leads me to believe that the slamfire events for the original M16s leading to the adoption of the #41 primer were in battery slam fires.

Jimro

[Slamfire]

So all this leads me to believe that the slamfire events for the original M16s leading to the adoption of the #41 primer were in battery slam fires.

I believe that all the M16 slamfires were in battery, but there is no data of the incidents to know what exactly happened.

This is interesting from a historical perspective:

Icord report page 4560
Mr. Stoner. Well, yes, because I knew that the rifle was, you know, was going to be used by the armed service and I wanted to make sure that we had adequate background on it before we went into it. Because the history, and all the testing that was done with the IMR propellants. We had another thing that happened on the Marine Corps test that went with that. We had some inadvertent firings of the weapon due to the primer that we were using. We were using a commercial primer in that round which is relatively soft and sensitive, and the Marines, on their firing, on their known distance range, would single load the weapon. They would put a round in the chamber and then let the bolt go home by pushing the closing button on it or the bolt catch, and the inertia of the firing pin would fire the weapon sometimes this way.

It was a very low frequency, but it did happen. So, of course, they wanted something done about it, and the Army found out about this. There were a couple of solutions. Either desensitize the primer, make it out of a thick material, or lighten up the firing pin. Well, what I recommended was lightening up the firing pin because I didn’t see-if you desensitized the primer too much it could cause failures to fire in the field.

In other words, we wouldn’t have enough energy to fire the primer under all conditions. And I-in this technical data package they decreased the sensitivity of the primer at the same them they went in and put the ball propellant in. So these were two things I objected to with Mr. Vee.

Here again, I didn’t know what the effects would be because we didn’t have all this test data, I mean testing, behind us that we had on the other ammunition. While the design on the firing pin, to lighten it, which was subsequently done by Colt, was a relatively simple thing, and in my opinion, wouldn’t detract from the performance of the weapon any. As I say this weapon was tested for years and years and before this inadvertent firing ever come up and it come up because probably we had a batch of ammunition where the sensitivity level on these primers were on the low end, or, I should say, the high end of sensitivity, and also, the fact that there were firing the weapon in a way that they formerly didn’t before, which was single loading, when it was an automatic weapon.

Usually the weapon was loaded from the magazine and when the rounds were stripped out of the magazine like it was intended to be used, this slowed the bolt down enough that you didn’t have the impact velocity to cause an inadvertent firing.

There were actually two things that I took exception to on that. I didn’t sit in on the Board that came up with the ammunition specification. I wasn’t asked to. I am not in the ammunition business. But, I have a good deal of interest in the ammunition due to the fact- usually you can’t change the ammunition without causing a change in the performance of the weapon.

Besides verifying that the early M16's slamfired, what Stoner claims is the real problem, that the USMC was not using the weapon properly, because they were not always firing from the magazine, is in fact, pure hogwash. The M16 procurement revealed that the Armalite and Colt Organizations did little in examining the technical performance issues of their rifle. As this testimony shows, Stoner only knows about primer sensitivity as a concept. He does not know how much energy is required to ignite an average primer, and he does not know the kinetic energy of his firing pin. It turns out, if you study this, the kinetic energy of his early firing pin was always above the "none fire" limits of commercial primers. None fire is a very important safety criteria: no primer is supposed to ignite when hit by a firing pin whose kinetic energy is less than the "none fire" limit. Stoner's design, the primers were always being hit by a firing pin whose kinetic energy exceeded the "none fire" limit.

Stoner does not accept any responsibility in this. He does not know what he does not know, and he does not know the numbers behind primer sensitivity. Stoner considers his design perfect. It was far from perfect, it was in fact an immature design that was not ready for combat.