Ring around the firing pin hole
- Thread starter jeanlikethis
- Start date
It can happen on any gun that has been shot a lot. I've seen it on K98's, Garands, and sporting rifles.
After confirming that my ammo wasn't leaking or blowing primers, I probably wouldn't worry about it.
From what I've read, the standard "fix" for this condition on a Mauser is to turn the bolt face on a lathe until it is smooth again, so it sounds like it is usually just viewed as a cosmetic problem.
After confirming that my ammo wasn't leaking or blowing primers, I probably wouldn't worry about it.
From what I've read, the standard "fix" for this condition on a Mauser is to turn the bolt face on a lathe until it is smooth again, so it sounds like it is usually just viewed as a cosmetic problem.
It's not uncommon, but that's really bad. I've never seen a Swede like that, it's usually just a ghost ring or very slight pitting.
Maybe reloads with loose primer pockets?? Mine all show a little shadow or pitting (except the Enfields) but nothing like yours.
Sorry for the crappy pic.
If you machined that boltface smooth you would have to requalify the headspace, which is already generous by SAAMI standards.
Maybe reloads with loose primer pockets?? Mine all show a little shadow or pitting (except the Enfields) but nothing like yours.
Sorry for the crappy pic.
If you machined that boltface smooth you would have to requalify the headspace, which is already generous by SAAMI standards.
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Below is the same problem on a AR15 bolt, the photo was posted at a AR15 reloading forum about loose primer pockets. The person who posted the photo said he was not worried about loose primer pockets and would just replace the bolt when it got bad enough. (Bad idea)
Bottom line, high pressure gas leaked past the primer and eroded the bolt face. This is associated with bad primers and stretched oversized primer pockets on reloaded cases.
I use pin gauges to check the cases primer pockets before priming.
And when seating primers any case that felt loose when seating the primer I use a Lee depriming tool. If the primer can be moved with just finger pressure the case goes in the scrap brass bucket.
Below Federal cases are noted for soft brass "BUT" much of this has to do with how thick the flash hole web is. The web adds strength to the base of the case and helps prevent radial expansion at the base of the case.
My scrap brass bucket below is over 95% factory loaded Federal "once" fired cases with over sized primer pockets.
Primer Gas Leaks from Google images below. (use mouse wheel)
http://s338.photobucket.com/user/joe1944usa/Firearms%20%20and%20%20Reloading/Primer%20Gas%20Leak/story
Bottom line, high pressure gas leaked past the primer and eroded the bolt face. This is associated with bad primers and stretched oversized primer pockets on reloaded cases.
I use pin gauges to check the cases primer pockets before priming.
And when seating primers any case that felt loose when seating the primer I use a Lee depriming tool. If the primer can be moved with just finger pressure the case goes in the scrap brass bucket.
Below Federal cases are noted for soft brass "BUT" much of this has to do with how thick the flash hole web is. The web adds strength to the base of the case and helps prevent radial expansion at the base of the case.
My scrap brass bucket below is over 95% factory loaded Federal "once" fired cases with over sized primer pockets.
Primer Gas Leaks from Google images below. (use mouse wheel)
http://s338.photobucket.com/user/joe1944usa/Firearms%20%20and%20%20Reloading/Primer%20Gas%20Leak/story
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It's not uncommon, but that's really bad. I've never seen a Swede like that, it's usually just a ghost ring or very slight pitting.
Maybe reloads with loose primer pockets?? Mine all show a little shadow or pitting (except the Enfields) but nothing like yours.
Sorry for the crappy pic.
If you machined that boltface smooth you would have to requalify the headspace, which is already generous by SAAMI standards.
What settings do you use to wash and dry your bolts.
And do you get any bolt peening in the dryer?
My wife couldn't stand the banging when I put them in the dryer, so now it's line dry only.
What settings do you use to wash and dry your bolts.
And do you get any bolt peening in the dryer?
Years ago I had a batch of about 200 rounds of 8x57 of Yugo manufacture that had problem with leaky primers.
I'm not sure if it was the age of ammo or manufacturing defect.
That was one of the reasons I got into reloading-I had to disassemble ammo and assemble it in new brass.
Downloaded it in the process too-ended up far more accurate than factory stuff and it didn't damage bolt face at all.
I'm not sure if it was the age of ammo or manufacturing defect.
That was one of the reasons I got into reloading-I had to disassemble ammo and assemble it in new brass.
Downloaded it in the process too-ended up far more accurate than factory stuff and it didn't damage bolt face at all.
That ring is the result of what is called "gas cutting". As many others have already mentioned, most centerfire bolts will show this "ring" to varying degrees after they have been shot a fair bit. If the primer leakage is particularly bad, you can get the pitting "gas cutting" that your bolt currently shows.
Corrosive primers, if they leak, will also contribute to this, and this can cause pitting around the ring if the bolt face is not cleaned regularly.
Corrosive primers, if they leak, will also contribute to this, and this can cause pitting around the ring if the bolt face is not cleaned regularly.
