Pitting on bolt face

[BW460]

I'm getting a circle of pitting on the bolt face. My guess is that it is gas leaking around the primer. I bought a Ballistic Tools gauge and always check my brass. I'm using LC LR brass and I have noticed that some of the primers seat very easily. This web page gives some dimensions: Ballistic Tools - Articles - Minimum and maximum primer and primer pocket dimensions. When I measure the dimension of the gauge go side, it is 0.208" and the no go side is 0.210". That seems consistent with the info on their web page. My question is this - they say the large rifle primer should measure 0.213". I measured the Winchester primers I have and they measured 0.210". The CCI primers I have measure 0.2105". That would explain why they are going in easily. Is there something wrong with the primers I have? Should they in fact be 0.213"? I hate to through out this brass, and I'm not sure any other brass will measure smaller.

Any thoughts?

 

[bergermeister]

Would say the answer is 'yes' as you stated. The solution is also as you speculated.. toss the brass. Been reloading since 1960 and to the best of my knowledge it HAS to be a gas cutting on the bolt face, and it obviously has to be from around the primer.
Swaging the pockets of military brass could create an oversize pocket depending on the punch used and/or the depth it adjusts the pocket to. Also different brands of brass will be more/less resilient to repeated reloads. It's pretty easy to lose track of the number of times a particular piece of brass is reloaded when feeding a semi-auto unless you are really careful.
If it has only been reloaded a couple times and the pocket is oversized it is either (1) soft brass (2) too hot of load (3) wrong type of powder.

Hope this helps- Cheers!

 

[2cants]

Winchester primers? I no longer use Winchester as all my bolts have been damaged by their soft primer cups.

http://smith-wessonforum.com/smith-...438-badly-pitted-bolt-face-poor-grouping.html

Since going to CCI all damage has ceased (same loads). I have done this across all rifles....223 to .338

 

[bergermeister]

Interesting 'take'..

Thanks for pointing that out 2cants. I have some ammunition loaded with Winchester primers and will keep alert for this type of erosion.