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Old August 26, 2013, 07:56 PM   #1
William T. Watts
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CCI 34 Primers

How comfortable would you feel using standard CCI LR Primers in a M-1 garand, I picked up a Beretta-Armi (Danish) Garand that I have fired very little because of the lack of CCI-34 primers. I've had the rifle at least 12 years and fired it less than 200 rds! When I purchased the rifle it had the correct Var barrel (I still have the Var barrel) that measured .3018", I replaced it with a Springfield barrel that measures .301" which looks to have been shot very little. William
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Old August 26, 2013, 09:50 PM   #2
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If I recall from reading around here the M1 is susceptible to slamfires(floating firing pin).

But I have no experience with the rifle, someone like Slamfire will be along to explain it better.

Edit: here it is.
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Old August 28, 2013, 10:11 AM   #3
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This is a very difficult thing to predict.

Slamfires are real, but are very rare. Slamfire probabilities for Garands/M1a’s may have been calculated but they are not in the public domain. Willian Davis performed calculations for slamfires in the early M16’s. These rifles had gone through development testing and troop tests and no pattern was observed until the rifle was fielded in quantity. Then the Army got enough slamfire reports that they figured out they had a problem. William Davis calculated with commercial primers there were 1:9000 chances of a slamfire with each shot, and he recommended a primer insensitivity for future procurement that would give a rate of 1:64 million (from memory, numbers could be faulty).

I believe military large rifle primers were made so they would have a slamfire rate about the same as was specified for the M16, about 1:50 million to 1:64 million. About the chances of dying from snake bite in the US, but about seven people a year die to snake bite, so XXit happens. Someone wins a lottery each month with odds of 1:100 million, so sometime good things happen too.

Garands and M1a’s have slamfired in battery, and worse, out of battery, with every primer on the market, including mil spec primers. Incidentally, search for slamfires in other military rifles. Every military rifle with a free floating firing pin has a slamfire report on the web. The rate of slamfires is higher with the more sensitive commercial primers, the most slamfiring primer on the market is the Federal 210. The CCI commercial primers have a reputation of being hard to ignite, so out of the commercial primers out there, CCI is a better choice. But the basic problem is, you can buy primers that are less sensitive on the average, but you don’t know what the sensitivity of each individual primer you load. Primers vary by sensitivity within the lot and overly sensitive primers exist regardless of brand or type. Overly insensitive primers exist too, we call them duds.

There are certain things you can do to reduce the risk of an out of battery slamfire in this mechanism. Full length size your cases, size with a small base die, and use a Wilson type case gage to set up your dies. Size to gage minimum. You absolutely do not want a long or tight case preventing the bolt from closing. If your cases are crunch fit to the chamber that free floating firing pin is rebounding off the primer before the lugs are in battery.

If the primer is a sensitive one it can ignite. You want cases that drop in the chamber without any resistance. You want to always feed from the magazine, or from a SLED. Stripping a round from a SLED slows the bolt down, reducing the kinetic impact of the firing pin on the primer. Never drop a fully retracted the bolt on a round in the chamber. If you don’t have a sled, lower the bolt to about here before letting go. Get your hand out of the way incase the thing goes off in battery: shooters have had their palms cut open by the operating rod.

You want to ensure that primers are below the case head. If the anvil is seated, and the primer cake pushed on the anvil, the primer is ready to ignite given enough energy. A high primer in a shallow pocket could cause an out of battery slamfire.
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Last edited by Slamfire; August 28, 2013 at 10:26 AM.
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Old August 28, 2013, 10:25 AM   #4
William T. Watts
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Thank you for your input Slamfire, you've reinforced my own thoughts, size cases to minimum length using a gage (L.E.Wilson). I have a Wilson gage for all the calibers I load for (the rest are bolt Guns), the down side I have 49 primers left that are no less than 10years old. I have activily looked for Mil Spec primers for at least two years and it could be longer, I refuse to pay $90 per 1K & HAZ MAT & SHIPPING. Until I find the correct primers my Garand will stay in the gun cabinent! William
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Old August 28, 2013, 10:28 AM   #5
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Look for TULA7.62, they are sold as Mil Spec and are great primers.

I don't know if you will find any, as the gun ban panic has freaked everyone out.

But, I am not concerned about slamfires with CCI standard primers. Primers I do not recommend are Federal and Winchester. Federal primers have always made the most sensitive primer on the market, their priming compound is special made to be more sensitive. Federals have been slamfiring and out of battery slamfiring in Garands for as long as reloaders have been using Federals.

Now Federal does make mil spec primers, but they are only releasing their mil spec small rifle primer to the public. While this is something to be encouraged for all primer makers, it seems that the explosion in the number of AR's on the market has driven this decision. I wish Federal and Winchester both made their complete mil spec product line available to the public.


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.

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.

Milspec primers for AR's not necessary?? See what the manufacturers have to say.

 by RemMan700 on Tue Aug 30, 2011 9:43 pm
Most people think that the CCI #41 is the only safe primer for fire arms with free floating firing pins such as the AR-15. I contacted several manufacturers to see what they had to say on the subject and if their primers were ok with these types of firearms.
Could you please tell me what the difference is between the CCI 400 primer and the CCI 41 primer? Does the 41 primer have a thicker/harder cup and less sensitive priming compound then the 400 primer?

A CCI 400 is our 'standard strength' of small rifle primer.

A CCI #41 primer is a 'magnum' strength of primer, equivalent to our CCI 450 Small Magnum rifle primer, ballistically. The #41 primer also has a feature to help lessen the chance of a slam fire in semi-auto types of firearms. This feature is that there is more distance between the tip of the anvil and the bottom of the cup, creating a slightly less sensitive primer. The #41 primer also has a thicker bottom on the cup than the CCI 400 primer. 

Linda Olin
CCI/Speer Technical Services
2299 Snake River Ave.
Lewiston, ID 83501

Said their 7 ½ primer is what is used in their ammunition and is safe for firearms with free floating firing pins.

Said their WRS primer was safe for firearms with free floating firing pins and would not cause a slamfire. However they use different primers in ammunition that is for their military contracts.
As for Winchester, they redesigned their primers before the turn of the century to make them more sensitive. These more sensitive primers are brass colored. As Winchester told me they made these primers more sensitive to "combat off center firing pin strikes". Unfortunately, what was a great primer to use in Garands/M1a's, the nickle plated WLR, was replaced with a more sensitive primer that has a relatively high number of slamfire reports.

Of the other commercial primers, Rem and CCI standard have the lowest number or reported slamfires. So, I would have no problems loading cases with CCI standard and going out and shooting them. I think the slamfire risk is acceptable in a Garand, probably less than the slamfire risk of SKS's or Chinese/Soviet Block firearms. Still, I have reasons for using the known less sensitive #34 type primers.

Regardless of what primer you use, always be conservative in your reloading practices, pay attention to the details, and always wear shooting glasses. I still have my vision after two out of battery slamfires with Garands (with Federal primers) because I was wearing my glasses. The pits on the first, and the shattered lens on the second, show me that without those glasses, my eyes would be full of brass particles.
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Last edited by Slamfire; August 28, 2013 at 06:27 PM.
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Old August 28, 2013, 07:50 PM   #6
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I dunno man. For years I loaded standard CCI and Federal Match primers for a Garand, this was before they made the Number 34 available commercially, and I never had an issue. Nonetheless, I used small base dies for this purpose, and fully sized the cases. The reason for the SB die is to prevent slamfires with the Garand/M14 and perhaps the AR15 as well.

Just toss your brass after 4 uses.
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Old August 28, 2013, 09:53 PM   #7
Marco Califo
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I am 100% comfortable using #34 primers for all my 308 loads, for FAL, and bolt. I bought enough and they are all I use. When they are available again, I will by more. 5 or 10K more.
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Old August 30, 2013, 07:47 PM   #8
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Like Marco, I only put c-34's into my M1A's. I bought them in 10,000 lot sleeves and just buy more when I run out. They are magnum primers and work just fine. Overkill? Maybe but a slamfire is something that I will "overkill" to avoid.
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Old August 31, 2013, 07:11 AM   #9
William T. Watts
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I am aware of the Tula primers, I've been on hold for two years and visited every website I can find many times without being able to find the correct primers. There is 1k primers on gunbroker for $90 that I assume will include hazmat plus shipping that I refuse to purchase. I have added my name/email address on several websites to be notified when CCI 34's or Tula 7.62 Nato primers arrive. They go pretty quick and one can only check their emails so many times in a day!! William
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