Hey fellas,
I'm having a problem with a pre-14 AI AX that suddenly started piercing factory primers, and sped up about 100fps. It's chambered in .260, which from other posts I've seen on here seems to be a candidate for this kind of problem, but I haven't heard of anyone having it happen with factory stuff.
It happened at a local match today using 130gr Prime (RUAG) .260. I had previously shot a match with the same ammo lot, and it ran just fine, albeit slow (2780 avg). Using that same ammo lot, I started the day just fine, but about 25 rounds in, the barrel suddenly sped up about 100fps on me (chrono showed 2870-2880 after the match. SD was still consistent, hovering around 10).
This wouldn't really have been a problem as I was waiting for the jump to happen (started going faster at almost exactly 250 rounds), but the jump in velocity was coupled with 8-10 pierced primers, a bunch of deep craters, sharper recoil impulse, louder report, etc.
That all pointed to a pressure issue off the bat for me, but none of the above were accompanied by any pressure signs on the brass, heavy bolt lift, or ejector swipes. Cartridge feeding seemed fine, and extraction was ok as well.
I thought it might have been a carbon ring to cause that sudden of a pressure spike, but I would guess that would come with nastier pressure signs on the brass than what was evident, and I wouldn't think something like that would develop after such a small round count.
The whole thing has me pretty puzzled, and I was hoping someone else here might have had experience with the same issue. I can't buy a small pin bolt body as it's a pre-14 3-lug bolt. Would it be as simple of a fix as getting the bolt bushed?
Thanks in advance.
I'm having a problem with a pre-14 AI AX that suddenly started piercing factory primers, and sped up about 100fps. It's chambered in .260, which from other posts I've seen on here seems to be a candidate for this kind of problem, but I haven't heard of anyone having it happen with factory stuff.
It happened at a local match today using 130gr Prime (RUAG) .260. I had previously shot a match with the same ammo lot, and it ran just fine, albeit slow (2780 avg). Using that same ammo lot, I started the day just fine, but about 25 rounds in, the barrel suddenly sped up about 100fps on me (chrono showed 2870-2880 after the match. SD was still consistent, hovering around 10).
This wouldn't really have been a problem as I was waiting for the jump to happen (started going faster at almost exactly 250 rounds), but the jump in velocity was coupled with 8-10 pierced primers, a bunch of deep craters, sharper recoil impulse, louder report, etc.
That all pointed to a pressure issue off the bat for me, but none of the above were accompanied by any pressure signs on the brass, heavy bolt lift, or ejector swipes. Cartridge feeding seemed fine, and extraction was ok as well.
I thought it might have been a carbon ring to cause that sudden of a pressure spike, but I would guess that would come with nastier pressure signs on the brass than what was evident, and I wouldn't think something like that would develop after such a small round count.
The whole thing has me pretty puzzled, and I was hoping someone else here might have had experience with the same issue. I can't buy a small pin bolt body as it's a pre-14 3-lug bolt. Would it be as simple of a fix as getting the bolt bushed?
Thanks in advance.
