Reloading .223/556 primer question?

[Mountainman6]

Guys I'm starting on some new loads for my AR it's a 1-9 twist barrel and my first load is a 556 case with 24 grains of CFE223 pushing a Hornady 55 gr GMX and I planned on using a #41 primer! Any thoughts on this? My main question lies in primer selection and if the 41 primer will work? I have read that the 41 just has thicker cup for milspec to prevent slam fire! Has anyone used or know if if the 41 is acceptable for my application for the 556 cases will it also work on the 223 cases? And is the 41 considered a magnum primer or not?

[chris in va]

Eh, I'd just go with a standard CCI SR primer. 3000 reloads through my AR with zero problems.

The 5.56 will probably have a primer crimp that needs removing. A simple chamfer drill bit will buzz it off. You can buy a dedicated crimp removal tool for that as well.

[2ndtimer]

According to CCI, the No. 41 primer uses the same data as the CCI-450 small rifle magnum primer. I have not personally tried the No. 41 primers, but have used a lot of CCI-400's, 450's, BR-4's, WSR's, RP 7 1/2's, Federal 205's and Wolf 223's. They all work well, and I haven't had any problems with any of them whether used in an AR or bolt action. For the AR, I try to stay with the CCI-450 or the Wolf 223 since I have heard they use thicker cups and could prevent a possible slam fire in an AR-15, but have also used the others mentioned without issues. Your load sounds pretty mild, but I have never loaded the GMX bullet, and perhaps the mono metal bullet requires lighter powder charges than the 55 gr bullets I load (Z-Max, bulk spire point, FMJ, Nosler Varmageddon).

[Ritz]

I'm using the standard CCI small rifle primers without incident in my AR reloads.

[H-D]

I have also used the standard CCI small rifle primers without incident in all my AR reloads.

[4runnerman]

As stated here the #41 ( White Box ) primers are for AR's to help with slam fire. Most newer AR's do not have that issue any more as you can see by post's here already. They are basically a CCI 450. I did use some ( still have some left ). What I saw was a loss in Accuracy from them. If you have access or are able to get- Just run with 450's or BR-4's.

[steve4102]

Use whatever Small Rifle primer you can find, they will all work, except the Rem 6 1/2.

The 5.56 case is identical to the 223 case in every way except for the primer crimp. It must be removed before seating a new primer.

[rebs]

I have used the cci 400, 450, and 41. They all worked fine

[Marco Califo]

I use #41 for all 223. I mostly shoot bolt guns. #41 are the only primer used in military 5.56 ammo., which means all M16 and M4 use them. They are considered to be magnum and will reliably ignite ALL powders consistently. They also will not slam fire. If you can get them, I would. I also only use #34 in 308 for all loads for same reasons.
But feel free to play your games next to your face.

[Beentown71]

I used the CCI standards and will be switching to # 41's. I get slightly stippled primers on my AR's.

[Jeff2131]

I can speak on behalf of the "slamfire". I have reloaded and shot close to 5000 .223's. The first time it happened it scared the crap out of me...hahaha. jjst wasnt expecting that sudden second shot. And everyone at the range looked as if i was shooting an automatic. It has happened maybe, 4-5times out of close to 5000reloads. I was using cci400 primers. Now with that being said, it MAY not been the primer, could have been an improper seating of the primer. Thats almost impossible to figure out after the fact though. But i continue to use the cci 400 as it is available to me. Id almost like to figure out how to make this happen consistantly just to be able to put a clip in and shoot "full auto" without a full auto rifle or bump stock. But thats just me wanting to have some ill advised fun.

[Mountainman6]

Thanks everyone for the info I've loaded ten rounds with 24gr of the CFE223 with the 41 primers and the 55gr GMX I know this might be a little light on the powder being it's only .5 above the recommended min based on the hornady data but I wasn't sure about the primer so I figured I'd start light and work up from there!

[A_Gamehog]

A few reloading books actually recommend a Magnum printer with ball powders. I like the 450's better but the 41's are fine also.

CCI also recommends a Magnum primer with ball powders.

http://www.cci-ammunition.com/produc...imer_chart.htm

[rlc323]

Starting at .5 grains above minimum is a good place. You are on the right track. I expect you will find something toward the mid range of the CFE223 load data that will work best with the #41 primers.

I use them because they are cheap insurance against a slam fire and they work well with W748 Ball Powder.

[Slamfire]

I can speak on behalf of the "slamfire". I have reloaded and shot close to 5000 .223's. The first time it happened it scared the crap out of me...hahaha. jjst wasnt expecting that sudden second shot. And everyone at the range looked as if i was shooting an automatic. It has happened maybe, 4-5times out of close to 5000reloads. I was using cci400 primers. Now with that being said, it MAY not been the primer, could have been an improper seating of the primer. Thats almost impossible to figure out after the fact though. But i continue to use the cci 400 as it is available to me. Id almost like to figure out how to make this happen consistantly just to be able to put a clip in and shoot "full auto" without a full auto rifle or bump stock. But thats just me wanting to have some ill advised fun.

I had an inbattery slamfire with brass WSR, when Winchester took off the nickel plate the made the primers more sensitive, and a Bud of mine has had two in battery slamfires with Federals. These were in AR15’s.

The idea that high primers cause slamfires is basically a canard, designed to misdirect the true cause of slamfires: firing pin kinetic energy and a sensitive primer.

CCI states in the article Mysteries And Misconceptions Of The All-Important Primer
http://www.shootingtimes.com/2011/01...motaip_200909/ that high primers are the most common cause for misfires. The primer anvil has to be firmly seated and the primer cake pushed into the anvil. If the anvil is dangling in the air or the cake not properly seated, a misfire will occur. I think it is very bad practice to have high primers or cocked primers because I don’t want anything but the firing pin hitting the primer. The primer is the igniter and I don’t full trust primers. On this website you will find posts where it took two hits to ignite a primer, the first strike seated the primer, the second set it off.

Prior to the turn of the century you could get into very heated arguments about whether the AR15 ever slamfired. There were no debates about M1’s or M1a’s slamfiring, there were so many on the firing line at NRA competitions that everyone had heard, or seen, a slamfire in one of those. The number of AR15’s being used has ballooned, while the number of competitors s shooters using M1a’s is now in the onesie’s and twosie’s, so few that people are now deigning that M1a’s slamfire! However, so many AR15 slamfire reports have surfaced that Federal, the maker of the most sensitive primer on the market, has introduced their military small rifle primer on the market place.

http://bulletin.accurateshooter.com/...imers-for-ars/

September 11th, 2011
New Federal Gold Medal Match Primers for ARs

Federal Ammunition has released a new type of small rifle match primer optimized for AR15s and similar semi-automatic rifles. The new Gold Medal® AR Match Primers, designated GM205MAR, have harder primer cups than the popular Federal 205M match primers. The harder cup is designed to perform better in semi-automatic actions that use free-floating firing pins. A Federal spokesman said that Federal’s “normal” 205M primers were not ideal for use in firearms, such as ARs, with free floating firing pins. Hence Federal designed the new GM205MAR primers. These are available now from major vendors such as Midsouth Shooters Supply, which offers the new GM205MAR primers for $35.22 per thousand.



Here's the skinny on the Federal GM205MAR primer. http://68forums.com/forums/showthrea...M205MAR-primer

My friend at RCBS contacted the expert at Federal, and this is what he was told:
Mix is the same as in the standard small rifle primer. The primer cup is thicker, as is the anvil. The thicker cup and anvil “should” desensitize the primer a bit, and “lessen” the chance of a slam-fire. Federal primers are in general, more sensitive than CCI and less tolerant of firing pin blows during loading into the chambers of the M1 Garand, M1-A, and AR platforms.
I hope this helps shed some light.



When the AR15 was first introduced into service the Army started having slamfires. At first the Army blamed the ammunition maker for “high primers”, which is the default position of the Army for this phenomena, but in the end the Army had to do two things: they lightened the firing pin, and they required the use of a less sensitive primer, the #41 primer.


You can use any primer you wish in the AR15, but using a more sensitive commercial primer increases the chance of a inbattery slamfire. Unlike the Garand mechanism used in the M1, M14, M1 carbine and Mini 14, AR15’s will only slamfire in battery. Unfortunately the Garand mechanism slamfires inbattery and out of battery making the choice of primer a more critical decision. From what I read, the military specified a primer sensitivity so that you have a 1:10 million chance of ignition on each round fed into the chamber. Commercial primers are going to be on the order of 1:2000, 1:10,000 chances of an slamfire per round. Having a round go off uncontrolled really makes a big impression. It has happened to me and I modified my reloading technique to reduce the risk. I don’t drop rounds in the chamber and hit the bolt release unless I am firing prone slow fire. During the standing stage, I drop a round in the chamber but lower the bolt about half way before letting go of the charging rod. For sighters in sitting rapid fire and prone rapid fire, I load from the magazine.

[Mountainman6]

Thanks everyone for the info I've loaded ten rounds with 24gr of the CFE223 with the 41 primers and the 55gr GMX I know this might be a little light on the powder being it's only .5 above the recommended min based on the hornady data but I wasn't sure about the primer so I figured I'd start light and work up from there!

[leefan]

FWIW I use 27 grains of CFE for a 55 grain FMJ. It closely matches the recoil of a Federal American Eagle .223 (I don't have a chrony).

[Mountainman6]

Also does anyone crimp their 223/556 reloads I've heard that many people don't crimp at all! A guy where I buy my supplies stated he doesn't and he didn't have a need for it! But if I was going to crimp I should just very lightly crimp my bullets any thoughts on this?

[Unclenick]

Mountanman6,

No, the crimp is not necessary. The military uses crimps in ball ammo, but skips it in sniper and match ammo. I've never asked, but suspect some of the several full auto weapons it has to work in will handle it a lot harder than the AR, specifically, does.

Follow the link to the first article Slamfire put up. That's one I've linked to frequently myself. The relevant information in it is that CCI reformulated their magnum primers to light spherical propellant with the older, more difficult deterrent coatings that you see in the WC8## series of rifle powders developed mainly in the 1960's at St. Marks. Today these mainly are sold as H335, BL-(C)2, H380, and US869. From looking at old primer flame photos it appears to me the addition of aluminum particles to throw hot sparks is one of the formulation changes that other brands of primers have now adopted, too.

The CCI tech I spoke with said the only difference between a CCI450 and a CC #41 is that the included angle of the anvil is greater. That is, the anvil feet are slightly shorter and broader. This means the primer has to be seated deeper to get the same bridge set (mix compression) between the tip of the anvil and the inside bottom of the cup.

The TulAmmo KVB556M is a NATO spec primer and is also a magnum primer. The ones I bought proved to be extremely consistent performers if properly seated, but they are harder to seat than others. I recommend the fixed seating depth tool built into the Forster Co-ax press with this primer, as it sets the primer 0.005" below flush with the case head, which does well for about anything. Seating too hard rather than too light is far better to do in this context.

The Federal tech I contacted said the GMM201MAR primer is identical to their GMM210M except that the cup is thicker. As it happens, I asked her specifically about the anvil because I knew that was how CCI mitigated sensitivity, but was told no, the anvil is the same as in the regular 210M. I suspect that if the RCBS tech was told that it was thicker it was a mistake, as a thicker anvil should tend to increase sensitivity by increased rigidity opposing the firing pin strike. However, if someone else wants to contact Federal, this can be reconfirmed one way or the other. Bottom line, though, is this is or the KVB (because of its consistency) are what I expect will work best with stick powders, as they light up just fine without extra fire.

Magnum primers sometimes increase pressure. This is seen as a velocity increase. In Handloader in 2006, Charles Petty documented a 55 grains bullet going from 3150 fps to 3300 fps changing between a Federal 210 and and a Remington 7½ BR primer, which is a good deal warmer. That was over 24 grains of Reloader 10X, a stick powder. QuickLOAD thinks it is the equivalent of using the 210 primer with 4% more powder (25 grains in this case). Other times magnum primers don't seem to make any change, and on a few, they actually can lower pressure and velocity. It's partly because of the different ways you can formulate primers to increase the amount of gas they make, which is what a magnum primer does (see that article again). In some situations, such as small case capacity, it can happen because the high primer gas volume unseats the bullet before the powder burn really gets well under way.

So, what's a fellow to do? Simple. To stay safe, always assume the worst, no matter how improbable. Assume your rounds are going to behave like the powder charge is higher. I think 5% reduction is close enough. But since load data typically has 10% reduction from maximum, that's usually safe enough. Just don't be skipping up somewhere in the middle of just one source of load data, or you may find yourself starting with a load that makes it hard for the gun to operate the bolt. Instead, start 10% low and just load 6 rounds in increments of 2% of the maximum charge; one 10% low, one 8% low, one 6% low, one 4% low, one 2% low, and one at maximum. Fire them one at a time, from low to high, looking for any kind of pressure sign. If you get all the way to the top without finding one, then you can start going down from there to find the best accuracy spot by any of several methods.

A lot of folks like to skip to the middle of the load range published in a manual. I like to discourage that, since I've twice encountered maximum loads (for my gun) that were the starting loads in some published data. This was older data, but it taught me there's little cost penalty to being conservative. As board member Clarke demonstrates regularly, it's actually hard to blow up many modern guns, and they are designed to handle proof loads, after all (though not a steady diet of them) that are normally a good bit stiffer than loads you see published. I just can't see battering the gun unnecessarily or finding you need a mallet to loosen a bolt when you could have avoided the problem with good load workup practice. If this means you try a couple of loads that prove not to be able to cycle the AR, so be it. Then you've learned where its lower limit is with the powder, and that can be valuable data, too.

[emcon5]

Also does anyone crimp their 223/556 reloads I've heard that many people don't crimp at all! A guy where I buy my supplies stated he doesn't and he didn't have a need for it! But if I was going to crimp I should just very lightly crimp my bullets any thoughts on this?

You should only crimp bullets with a cannelure, but even with autoloaders with proper neck tension you shouldn't need to.

Test for yourself, make up a dummy round, sized but no powder or primer. Measure the OAL with your calipers.

Load it in a magazine, and chamber it by dropping the bolt on it. Repeat 5 times, then measure again. If it is the same OAL, you don't need to crimp. If it is not, you messed up your sizing...

[Jeff2131]

I can speak on behalf of.crimping too! I was crimping my rifle rounds and then Bart B. Spoke of suffcient neck tension and actually losing accuracy when.crimping rifle rounds such as the .223 and .308. I stopped crimping and just seated with no crimp and i could visably see my groupings get tighter. Also, he reccomended a cylidrical powder or extruded powder over ball powders and that has proven to be much better as well! Ive totally scrapped my 4320 recipe with crimped at the cannelure rounds and have switch to 4064 and 3031 with zero crimp and ive had much nicer results at the range!

[steve4102]

If you are going to load for an AR you should read this. It may help answer a lot of your questions and concerns.

http://www.exteriorballistics.com/re...sgunreload.cfm

Note the section on "Neck Tension". Even the bullets in Factory ammo with their much tighter "bullet pull" than handloadeds will creep forward without a crimp. It's up to you to check out Your ammo and decide on how much forward bullet creep is acceptable to you. I choose None, so I crimp with the Lee Factory Crimp Die. YMMV