Primer Cratering With Factory Ammo

[Scorpio64 5,147]

I took my new 308 hog hammer out to the range today for its first test firing and zeroing the thermal scope.  There are two potential problems I noticed.

First, the case heads were damaged, like, clawed up on extraction.  Never seen anything quite like it before on a case head face, but my SPR (which is slightly overgassed) will chew up a rim every once in a while, but nothing like this.  It's hard to tell from the pictures, but brass has been sheared off the face.

Second, what's up with the cratering?  I used factory PPU and MEN, both reliable brands, so it's obviously not a hot load.

While researching, I came across a YT video that could explain the cratering.  The video explains how a bolt face could have a firing pin hole that is too large, and the case head just gets mashed into it.  The fix is typically a bushing in the firing pin hole, but they do that on rifles that have been fired many thousands of times.  This rifle has a brand new BCG.

So, any thoughts on what is causing the claw marks and the cratering?

 

[silverado427 10,675]

I'm just throwing this out there,  Is there a burr on the extractor and is the firing pin to long.

[Scorpio64 5,147]

22 minutes ago, silverado427 said:

Is there a burr on the extractor and is the firing pin to long.

There does not appear to be any burrs on extractor, however, I had a closer look at the bolt and the lug face is not true.  There are what look like burrs (bumps) on a couple of the lugs.  I got a better look with a loupe and the entire BCG looks like it was half assed.  The QPQ is all buggerd up with runs and globs, so not a good coating.

I'll mic the firing pin tomorrow.

[GRIZ 3,369]

AFAIC there is something with the extractor to chew the rims up.

You might have a firing pin/firing pin hole issue.  I've fired a lot of MENwhich is NATO spec in semis and bolt guns.  Never saw any cratering.

I'd tend to agree your bcg is half ass without seeing it.

JMO