How true is the whole Garand slam-fire theory?

[Kayser]

With lots of Lake City brass piling up, I wouldn't mind moving into some reloading for my Garand. I've seen conflicting reports about the Garand being prone to slam-fires with normal primers. The recommendation being that you use the special CCI mil-spec primers which have a harder shell that resist light primer strikes from forward bolt motion.

Do you guys generally subscribe to this theory, or is it mostly hoo-ha?

I'm a highly safety-oriented guy when it comes to reloading, so I figured I'd get the answers from the experts.

[James K]

I think it is mostly either baloney or a misunderstanding of the term slam fire.

In some cases, the term is used for a condition in which the hammer is jarred off the sear (usually due to amateur "trigger work") and falls either without the trigger being pulled or with only a very light pull that the shooter might not even realize was made. That is a dangerous condition, but it is not a slam fire. The only rifle I have had a chance to examine that supposedly slam fired in fact had a ground down sear, the result of an attempt either to reduce the trigger pull or to make the gun fire full auto.

What is usually meant is that the forward moving bolt stops and turns to lock, but the firing pin has enough forward momentum to fire the cartridge. This is not easy to envision, since (barring a defective rifle) the design is set up to preclude this from happening, nor is it easy to see the firing pin having enough momentum left to fire the primer even if there should be a part failure (broken "L" on the firing pin or worn receiver cam).

Another possibility is that the firing pin will have enough momentum to fire the cartridge when the bolt stops, but before it turns to lock. This also should be prevented by the rifle designand again seems unlikely in view of the relatively low firing pin mass. Further, if that happened, there would be an out-of-battery fire, and the rifle would be wrecked with possible injury to the shooter. This is not usually reported in cases described as slam fires.

All the design safeguards depend on the rifle being in good condition. If the rifle has been tampered with, extremely worn, or broken, things can happen that should not, though a true slam fire is probably not one of them.

So, to answer the question, you should have no problem with "slam fires" if the rifle is in good condition. I have fired thousands of reloads from an M1 with no problems using regular primers.

That being said, I see no problem with using hard primers if it makes you feel better.

Jim

[444]

I have never had one, but you can easily see an indentation on the primer if you chamber a round and then eject the live round. It doesn't take anything at all to convince me that under the right conditions, you might have a slam fire. That takes care of my own opinion based on my own eyes.
Now lets move on to other possible evidence.
This situation has been reported to be an issue for many years. It is reported by anybody I ever read about handloading for US Military rifles. It is reported by the NRA, the CMP, and Springfield Armory even puts a reprint of an article about it in the box with their new rifles. Many of these sources include pictures of blown up rifles.
I don't have to have it happen to me to believe all those organizations.
If you don't believe any of them, why would you believe someone you don't know on an internet gun forum ? Why would you gloss over the information they provide yet call people you don't know on the internet the "experts" ?
Then the real question that is almost never asked on these on-line gun forums: if you have "X" number of people come on here and say; "I load regular primers all the time and I never had a problem": does this mean it won't happen to you ? Or does it just mean you are willing to be as foolish as they are ?
Or do you just want someone to tell you it is OK so you can go on ahead doing what you were going to do anyway ?

Just a few points to consider. YMMV

[ribbonstone]

Don't think it's limited to any one make of rifle, it's just that semi-autos are the only type to usually cycle with enough force to set off a high primer.

Which is what most slam fires (in a properly made rifle) proabably are: a high primer smacked by the force of semi-auto chambering. Are a multitude of mechanical failures or maladjustments that could cause a slam fire...and perhaps some rifles are more prone to this simply becasue so many non-standard parts have been "fitted" (or just slapped in there in the niave belief that all parts are interchangeable) over the years.

Considering the healthy "wack" the firning pin gives a primer, using the harder cupped CCI mil-spec type primers wouldn't really casue any problems and might help put your mind at ease (but I'd have the gun gone over carefully for correct firing pin fit and length).

-----

Wondering if a LOOSE primer pocket (many loaded cases can develope this even without over-loading) couldn't cause a slam fire. Loose enough to be jerked "out" by cycling, and slammed foward at chambering. (OK..know inertia and such wouldn't really jerk the primer out...it would tend to stay still as the case moved forward ...but the effect would be to act/look like the primer moved out.)

[Steve in PA]

Let's see.......over two years of owning a Garand. Have fired over 2k rounds of handloaded ammo, all with CCI 200 primers and not one slam fire. Just make sure your primers are seated properly, not sticking up and you'll be fine.

[444]

I know that Springfield Armory probably doesn't know as much about these rifles as the internet guys, but, you can go to their website and they have the owners manuals for their rifle available for download as PDF files. For example: here is the manual for their M1 http://www.springfield-armory.com/Ma...randManual.pdf
I wonder what this means, under the heading of Ammunition on pages 5 and 6 ?
"The specifications for standard military ammunition include harder primers to withstand the slight indentation from the firing pin when the bolt chambers a cartridge. This slight indentation is normal. The use of civilian ammunition with more sensitive primers or handloads with commercial primers and/or improperly seated primers increase the risk of primer detonation when the bolt slams forward. This unexpected "slam fire" can occur even if the trigger is not being pulled and if the safety is on. Use of military specification ammunition will help avoid this............................Also see enclosed article on "Slam Fire" written by Wayne Faatz. "

Then there is CCI: http://www.cci-ammunition.com/defaul...=10&prod_id=30

"Military-style semi-auto rifles seldom have firing pin retraction springs. If care is not used in assembling ammunition, a “slam-fire” can occur before the bolt locks. The military arsenals accomplish this using different techniques and components—including different primer sensitivity specifications—from their commercial counterparts. CCI makes rifle primers for commercial sale that matches military sensitivity specs that reduce the chance of a slam-fire when other factors go out of control*. If you’re reloading for a military semi-auto, look to CCI Military primers.
*Effective slam-fire prevention requires more than special primers. Headspace, chamber condition, firing pin shape and protrusion, bolt velocity, cartridge case condition, and other factors can affect slam-fire potential. "

Here is another guy that didn't get the internet word: Glen Zediker has a download here: http://www.zediker.com/downloads/14_loading.pdf that goes with his book Handloading For Competition The download is entitled Reloading for the Match M14 but most of it applies to the M1 as well: especially the part about slam fires since their bolts are extremly similar. If you download the article and turn to page 7, start reading where it says "Aberrant Behavior: look ma, no trigger".

[Kayser]

444 - great stuff. You've convinced me

No need to reload '06 yet as cheap surplus is still available, but someday I may need to delve into it. Thanks!

[444]

I am just trying to be safe.

Everything you need to know about loading safe, and accurate ammo for these rifles in contained in that article by Glen Zediker.
I don't think any of this information should scare anyone away from handloading for the M1 (or M1A or AR15: all suffer from the same problem) but just make sure you understand what you are doing and use safe methods. Loading for these rifles is not as simple and carefree as loading .38 Specials for a revolver.

[SakoL61R]

I'll stand behind 444 on the above.
Well said! Yes, I do reload for military style semi-auto rifles and have been doing it for many years.

[Tim R]

I would believe Zediker before even thinking of believing anything Springfield Armory has to say......I've owned and reloaded for my M-1's before they even built one. Lets not forget todays Springfield is not the Springfield of old. Both my Springfield M-1's are the real deal.

[Smokey Joe]

Kayser--Slam-fires are much more an issue with the SKS than with the M1. I've experienced this with the SKS. Not pleasant, but not dangerous if you don't panic and drop the rifle before it is all done.

Slam-fires can happen in any autoloading firearm which does not have a firing pin return spring. The SKS doesn't have the spring. I understand that several American military weapons don't have it either.

Anyhow, the problem occurs when excess grease or some other material becomes lodged in the firing pin channel, within the bolt, preventing the firing pin from moving normally. Then you suddenly have an automatic-firing weapon, with a fixed firing pin, like a Thompson sub-machine gun.

The #1 solution is to clean clean clean that firing pin channel. Then lube it with light oil, if at all--never with grease. #2, in the SKS, is to have a firing pin return spring installed. Don't know if anyone modifies Garands in that way. #3 is to use CCI #34 primers when reloading--as noted above, they are mil-spec; harder than commercial primers, and less prone to slam-fire.

And of course, above all, with the M1 as with ANY firearm, the absolute prevention of a problem is called SAFE GUN HANDLING. This will save you no matter what malfunction occurs.

[30Cal]

If you have a high primer, you're probably going to have a slamfire regardless of what primer you use.

I've gone through a big sleeve of WLR primers without any problems, but I also take positive measures to minimize the risk of slamfire. I uniform my primer pockets so that the primers are ~0.010" below flush. I check each primer by hand after seating to ensure it's below flush, and I clean out the primer pocket after every sizing. I also set my sizing die with a case gage to ensure that the shoulder is set back adequately.

I feed every round out of a clip or sled (magazine in the case of the M1A) to regulate the closing speed of the bolt.

Read the information, and understand the contributing factors. You can mitigate practically all of the risk, but there will always be a certain level of risk that you must assume when reloading and shooting.

Finally, God forbid a lawyer go hungry in this country.

Ty

[Scorch]

Great rant, 444. I agree with you, the folks who make the rifle, ammo, or monitor thousands of reports annually probably have a good understanding of the rifle's tendencies. I don't shoot an M1, and don't know whether they are prone to slam firing or not, but it seems to me it would be wise to listen to the pros. Saying "I have fired XX thousand rounds and this never happened to me, therefore it can't happen" is a fallacy of logic.

But we do have all these "experts" here on the internet who say running with scissors is OK, you can take candy from strangers, and the M1 will not slamfire . . .

[HSMITH]

I have had a slam fire with a Garand. Federal GMM primers, seated by hand and darn sure wasn't a high primer. Put the gun away and checked it over, nothing wrong with it at all. Some of the highpower shooters I have talked to have also had a slamfire with M1's and M1A's. It IS possible. It might not happen to you in tens of thousands of rounds, but don't dismiss the possiblility that it might happen.

CCI military primers in my autoloading rifles now, there is no reason not to use them.

[Unclenick]

I agree with 30 CAL. I also uniform my primer pockets both for depth and profile (Wilson tool), then seat with a K&M primnig tool because it lets you positively feel the primer bottom out without crushing it. I have been using the Federal 210M primers since getting my DCM Garand in the 80's, and have done so for 1000's of rounds in three different Garands without incident.

That said, I have been on the line at Camp Perry on more than one occassion when the order to load was given and a "bang" answered back. The main lesson I take away from it is: never chamber a live round in the military rifles when they aren't pointed safely toward an actual backstop or safe impact zone; certainly not in the house if your marriage matters to you. Secondary lesson: take the time to read Kuhnhausen or another source that gives you inspection points and critical fit dimensions (like firing pin protrusion), then take the time to inspect and measure that stuff. This goes to Ribbonstone's point about how many mix-and-match parts and assemblies are out there. You get to learn more about the gun doing this, so it is part of the fun.

If you bought your gun from the CMP, use them as a resource. They don't build up match guns, but Mark Johnson and the other guys at Anniston have all the inspection gear and experience in identifying safety issues you could wish for and will stand behind what they've sold as being in functional condition.

Also a thumbs up on Glen Zediker's book.

Nick

[Rico567]

Never had a slam-fire myself. Never met anyone who has. Never read a credible anecdote of one happening. However: I use both CCI #34 and #41 primers in my military semiautos. An ounce of prevention....

[Unclenick]

As I said, I've heard it when on the line as a shooter. Of course, you never really know for sure that someone who claims a slam-fire didn't stick his finger where it didn't belong and just claimed it to save face? Once, however, it happened when I was a volunteer line coach during one of the Ohio Rifle and Pistol Association's old Spring DCM clinics in the late 80's. Another line coach was standing over the beginner whose gun fired, watching to be sure he was loading correctly when it happened. He and the shooter both swore that not only was the student's finger not inside the trigger guard (hard to do unless you're a southpaw), but that the safety was on at the time. The RO had the gun pulled from the line and put aside for an armorer's inspection and had the student issued a different gun to use (these guns belonged to the organization, not the students). I don't know whether the inspection found anything subsequently amis or not?

Slam-fires are pretty rare, but in those big shoots, when you may have 500 or more participants all shooting Garands, the probabilities of witnessing a slamfire go up. The CMP's John C. Garand match during the Nationals this year already has over 1200 competitors signed up. Head up and participate or watch. I'd say there's a 50/50 chance of it occurring once in a group that large going through a full match. That's going to be over 36,000 slow fire rounds loaded, all in as-issued Garands. The ammunition will be military ball, so that minimizes the chances, but doesn't make them go away completely.

Nick

[Tim R]

Thanks Uncle Nick for reminding me to help educate, not throw stones at Springfield.........

It seems the report of a slam fire is also most often heard about when the rifle is being used for slow fire, another words 1 single round loaded in the chamber and the bolt allowed to fly forword as it should be.

A good way to reduce bolt speed is to use a SLED. This is a mod'ed clip in which 1 round can be loaded and stripped by the bolt when closing. The use of a SLED wil also reduce the chance of a buggered up thumb as well. The SLED's can be found at Champions Choice and Creadmore Sports.

Be careful at these 2 places, they have a lot of neat stuff.

[azredhawk44]

I own an M1A, and I want to get a Garand, an M1 Carbine and all those spiffy 1940's era weapons.

I handload and I am meticulous with my brass prep out of respect for slam fires. I've never had one, but they don't sound like the best event one could have at the firing line.

I resize after each shooting. I clean the brass after depriming so as to clean the primer pocket thoroughly.

When brass is new, I uniform the pocket depth with an EJS Primer Pocket Uniformer. I also deburr the flash hole. This keeps the primer recessed just enough that I don't have it directly exposed to the force of the bolt.

It's tedious, especially when starting out and all your brass might be new or un-uniformed, but these rifles are expensive investments and deserve it.

[Smokey Joe]

Azredhawk44--Good on you wanting even the new brass to be perfect.

Suggest you look into using Norma or Lapua brass...pricey, but the primer pockets are all already uniformed, the flash holes drilled not punched, so no need to deburr, the case walls all the same, weight of each case the same as the next, case necks and shoulders all discolored exactly the same from annealing--You couldn't make 'em more uniform yourself if you tried. Haven't measured case run-out myself but the report is they are uniform there, too. Great stuff!!

I use it in my "good" rifles. My "just shooters" get Winchester or Remington cases. The target pistol gets Starline brass, which is as good as it gets in pistol brass.

[azredhawk44]

Smokey:

That stuff is expensive! Especially when you don't own any .308 brass.

I started off with pre-loaded milsurp south african berdan primed stuff. Just to get a feel for the rifle.

I shot about a hundred rounds of commercial .308 ammo, but didn't like the cost.

Finally decided I would accept the risks of reloading for semiauto rifles, and bought 100 pieces of Winchester brass.

Each subsequent order from midway also came with 100 cases, for the next 3 orders. Then the last 2 came with Remington.

Now I have 500 cases... I can slow down and look into premium brass. I bought my first box of Nosler .308 brass... it hurt to pay $30 for 50 cases. I don't know if I could do Norma or Lapua. They would definitely have to be worth it. The nosler may be worth it since the pockets seem very uniform as well as the lengths. The mouths are chamfered too.

Once I have the prep work done on the brass, I don't have to do it again, except trimming to length every 2-3 loadings.

I haven't yet tried the CCI military primers though. I just use the Winchester WLR or CCI 200 primers and haven't had any issues. The indentation is very small when letting the bolt carry a cartridge home.

Kayser: get into it. It's worth it, especially when you really start to get peak accuracy. As long as you respect the primer pocket shape, it's worth it.

I wonder, for all you guys here:

The CCI military primers are more of a magnum primer, right? I could see that as being very beneficial in a semiauto rifle, since the bolt inertia may "push" the powder to the forwardmost part of the case, farthest from the primer. Can anyone comment on that? Or is the used case capacity with most powders high enough that this isn't an issue? My H4895 load looks pretty full, but when I was using H335 there seemed to be a lot of room left in there.

[maggys drawers]

I've always used CCI #34 primers since I have pretty good access to them. I figured if the military had a spec on bullets, powder and cases that I sure wouldn't ignore that, so they had a reason for the spec on the primers, too. I was thinking maybe it was because the same ammo was used in the .30 cal machine guns, too- which might be a little more prone to slam fires...

The CCI military primers are more of a magnum primer, right?

I have heard the reason for this was for reliable ignition in the extreme temps the ammo was used...anywhere from Europe in the dead of winter to the jungles of the south pacific in the summer.

[Smokey Joe]

Azredhawk44--Yeah, the hi-grade brass is pricey, no question. Worth it IMHO, for all the prep you don't have to do to it, and the utter uniformity.

As to Nosler brass--have no personal experience with it, but from what I've read about it it is also hi-grade.

Military primers--The difference, as I understand it, is just that they are less sensitive to an impact, because either the little cup is thicker brass, or because the priming compound is just harder to set off. Aside from that they are ordinary large (or small) rifle primers. Now, that's just from my reading and from discussion on these fora. If there is a genuine expert on military rifle primer construction/specifications who wishes to disagree I'll gladly stand corrected.

[Peter M. Eick]

My attitude is that my SuperMatch and NationalMatch M1A's are expensive while c-34 primers are cheap insurance. I have had no problems with c-34's as long as you recognize they are magnum primers and need to be downloaded a bit for 4895 or 4064. Why risk a nice rifle and the potential personal damage of a slam fire?

Besides, here is what my Super can do at 100 yards with c-34 primers off the bench. 50 shots! In my mind, that is good enough for a primer and load.

[Unclenick]

If you read CCI's website's spec on C-34's, it claims that they meet the military's reduced sensitivity specification and that they are "optimiized" for spherical ball powder. Ball powder is harder to light, so they make these primers warm, and the information says to use magnum primer loading data. I don't know whether that is a precaution or whether they are actually magnum primers? My guess is that they are. Probably just the regular CCI magnum primer formulation put in harder cups. Real mil-spec primers also have to meet reliability standards at extreme temperatures, which can matter to hunters. I know Garrett Cartridges uses mil-spec primers for their temperature relibility standards, but not because they are being fired in semi-autos. I know I wouldn't want temperature reliability issures if a polar bear were charging me. What I don't know is whether the CCI C34's meet these other military specificaitons as well? They don't claim to on their information page.

Nick