Primer choice for M1 Garand

[tcoz]

For those of you who handload .30-06 for an M1 Garand, what CCI primers do you use? I'll be loading 150gr FMJBT over IMR4895. I use CCI 5.56 NATO SRP's for my AR's but I don't know whether regular, magnum or NATO primers would be best for the Garand which I ordered yesterday from the CMP.

 

[george d dennis]

Garand

cci 34 7.62 lg rifle,

 

[tcoz]

Thanks. That's what I figured I'd use even though I've read a lot of people just using regular CCI 200 LRP's. Don't want to chance a slam fire, especially on that rifle.

 

[Steve in PA]

I've fired several thousand handloaded rounds through my M1 Garand using regular CCI 200 LR primers. No issues.

I've also loaded and fired many more thousands of handloaded rounds through my AR using regular CCI 400 primers. Again, no issues.

 

[Reloadron]

When I have them the CCI #34 But no reservation using WLR (Winchester Large Rifle) or CCI BR2.

Ron

 

[Comrade Mike]

When I still had my Garand I had absolutely no problems with Winchester Large Rifles. Just seat below flush

 

[1KPerDay]

Make damn sure they're seated below flush and you can use CCI200 just fine. CCI34 may give you more peace of mind. I believe the 34 is considered a magnum primer but for the Garands you won't be loading max anyway. Keep bullet weight below 170 grains and 4895 around 47 and you'll be golden.

 

[1KPerDay]

Btw congrats on your purchase! You're going to love it. Be sure to full length size and use a case gauge (Wilson or similar). I generally size to the minimum step on the gauge. You may get fewer reloads but you'll be safer. The rims will probably be mangled after 4-5 reloads anyway. I have some cases with that many loads and they're still showing no signs of separation. I load a bit light though.

 

[tcoz]

Btw congrats on your purchase! You're going to love it. Be sure to full length size and use a case gauge (Wilson or similar). I generally size to the minimum step on the gauge. You may get fewer reloads but you'll be safer. The rims will probably be mangled after 4-5 reloads anyway. I have some cases with that many loads and they're still showing no signs of separation. I load a bit light though.

I use a Sheridan slotted gauge for 223 and 300 BLK and will definitely get one for 30-06. It sizes to minimum SAAMI spec. It's about $65 but well worth it.

 

[TenDriver]

I use Tula LR as deep as they'll go.

 

[1KPerDay]

I use a Sheridan slotted gauge for 223 and 300 BLK and will definitely get one for 30-06. It sizes to minimum SAAMI spec. It's about $65 but well worth it.

Thanks, those look cool! The Wilson and similar don't gauge diameter, just headspace and length.

 

[Sunray]

"...I've fired several thousand handloaded rounds through my M1 Garand using regular CCI 200 LR primers..." Me too. 168's with IMR4064, mostly. IMR4064 gives more consistent accuracy than IMR4895.
CCI "milspec" primers are nothing more than magnum primers. Not required.
Slam fires are caused by improperly loaded ammo, usually high primers. Not the rifle.
Read the manual and understand how to load an M1 Rifle. Garand Thumb is operator failure.
.pdf manuals are here. Note the need for the provided UN & PW.
http://www.biggerhammer.net/manuals/

 

[tcoz]

Thanks, those look cool! The Wilson and similar don't gauge diameter, just headspace and length.

With the Sheridan, if it gauges ok it's guaranteed th chamber in your rifle. If it doesn't gauge ok it might still chamber depending on how tight your chamber is.

 

[mdi]

Yep, add me to the "standard CCI large rifle and 4064 group". I've only fired about 1500 reloads (using Hornady and HXP brass) and narry a problem. I've read about slam fires, but can't see a reason to blame primers. My gun is clean and my CCI primers, seated correctly, work quite well..

BTW; My Garand is more fun than my 10-22! Even chasin' brass...

 

[ArchAngelCD]

When available I like to use CCI #34 primers for M1 ammo but I have used standard Win LR primers and CCI-200 primers without incident. CCI #34 or CCI-250 primers are probably the best choices for M1 ammo.

 

[tcoz]

I can only speak to the AR platform but the principles are the same. Because the firing pin is free-float, it "slams" into the primer every time a round is chambered. For evidence of this, chamber a round from a loaded clip (magazine on an AR) then take it out and you'll see a slight indentation on the primer where the firing pin hit it. This hit has been known to cause a slam-fire which although not common, isn't unheard of either. More than one of my friends have experienced them. Often, a primer that hasn't been seated deep enough is the cause but that isn't always the case. Primers don't cause or prevent slam-fires, but by using one that has a thicker cup such as a magnum or especially a NATO primer, you can really decreases the chances of one occurring.

NATO primers were developed because of a request by the military for a primer that was more resistant to slam-fires. I'm really only familiar with CCI, but their magnum rifle primers are a little hotter than their standard ones and they also have a slightly thicker cup. Their NATO primers are also loaded as hot as the magnums but also have a slightly thicker cup yet. Sometimes they're more expensive than magnums which are usually priced the same as standard so many people use them. All primers are priced the same where I buy them so I use the NATO primers.

 

[W.E.G.]

Any large rifle primer should work fine in the Garand.

The thickness of the primer cup of large rifle primers is the same, whether its a "military primer," or a "magnum" primer, or a plain ol' primer.

I've used all of the above varieties in the Garand.
I see no difference whatsoever in performance.

 

[cfullgraf]

My experience is similar to most of the previous posters. I have used mostly Winchester Large Rifle primers. I have probably used some CCI200 primers as I do buy CCi primers but I did not go back and check my records.

The last primers i bought for my Garands are CCI 34 primers but I have not loaded any 30-06 ammunition in several years, I'm still working off my inventory. I bought the CCI 34 primers because they were priced right and available at a time when supplies were short.

 

[USSR]

Have always used Winchester LRP's until recently. Now using Tula LRP's due to price. Only LRP's I won't use in a Garand are Federals due to them being more sensitive.

Don

 

[tcoz]

The thickness of the primer cup of large rifle primers is the same, whether its a "military primer," or a "magnum" primer, or a plain ol' primer.

I've only used small rifle primers and I know for a fact that the cup thicknesses are different between standard, magnum and NATO (mil-spec) for them. If I understand you correctly you're saying that large primers differ from the small primers in that the cup thicknesses are all the same on the large ones. If that's actually the case, how do they then make the NATO primers less sensitive which they are and is the basis for their existence?

 

[Reloadron]

I've only used small rifle primers and I know for a fact that the cup thicknesses are different between standard, magnum and NATO (mil-spec) for them. If I understand you correctly you're saying that large primers differ from the small primers in that the cup thicknesses are all the same on the large ones. If that's actually the case, how do they then make the NATO primers less sensitive which they are and is the basis for their existence?

According to WEG:

The thickness of the primer cup of large rifle primers is the same, whether its a "military primer," or a "magnum" primer, or a plain ol' primer.

While the below chart does not include all large rifle primers, of those it does include it runs with WEG's statement.



All of the large rifle primers reflect the same cup thickness of 0.027". So why are some said to be more sensitive? My best guess is some may use a softer alloy composition, they may have a different cake mixture (more sensitive cake) and while the same thickness they do not share the same cup height. Beats the heck out of me which makes some more sensitive. Then too the Winchester flavors at 0.121 have the greater height and I would think that would make them more sensitive but it doesn't work out that way.

Finally, as Don mentions:

Have always used Winchester LRP's until recently. Now using Tula LRP's due to price. Only LRP's I won't use in a Garand are Federals due to them being more sensitive.

For decades I have believed the Federal primers to be more sensitive also. Here is an interesting comment on that taken from MASTER PO'S M1 loads (Courtesy of the NRA).

Master Po's Ancient M1 load secret

This is my personal M1 load I use in my CMP M1. It will shoot better than Master Po can. I worked this load up, as you should for your own rifle.

Remington .30/06 cases, flash holes deburred and weighed within 1 grain.
Federal GM210M Primers (Master Po has heard the horror stories of Federal match primers in the M1/M1A rifles. If you're squeamish or new to reloading, use Winchester Large Rifle)
47.0 grains IMR 4064
Sierra 175 grain MatchKing
Overall length 3.340 inches

This load, in my M1, duplicates almost perfectly the M72 match load specification with a very low standard deviation. Groups off the bench run 1 - 1.5 inches with the original 1945 barrel on the rifle. Of course, Grasshopper YMMV.

Take it all for what it may or may not be worth. The Hornady 9th Edition where they list M1 Garand Load Data calls out the use of WLR (Winchester Large Rifle) primers.

Ron

 

[tcoz]

Excellent info. Thanks for providing. If I remember right, CCI 41 NATO 5.56 small rifle primers have a cup thickness of .027" which is exactly the same as ALL of the large rifle primers. Based on this it would follow that the use of NATO primers to decrease the chance of slam fires isn't necessary. The next question would be whether standard or magnum primers are indicated. Hodgdon once told me that magnum primers are recommended with spherical powders because they are coated to control combustion. Being that 4895 is an extruded powder, logical thinking would tell you that standard primers would be recommended. I'm going to shoot an email to Hodgdon and see what they say.

 

[ArchAngelCD]

In reality it's really not the cup that helps prevent slam-fires, it's the compound sensitivity.

 

[Reloadron]

In reality it's really not the cup that helps prevent slam-fires, it's the compound sensitivity.

That would be my thinking and what I have believed. It just makes the most sense to me anyway looking at the possibles.

Ron

 

[cfullgraf]

In reality it's really not the cup that helps prevent slam-fires, it's the compound sensitivity.

Right.

From CCI's web site...

http://www.cci-ammunition.com/products/primers/primers.aspx?id=30

CCI No. 34 and No. 41 Military Rifle Primers

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.



Features and Benefits

Mil-spec sensitivity
Initiator mix optimized for ball/spherical propellants
Available in large (No.34) and small (No. 41) rifle
Use the same data as CCI Magnum primers