Gen 2 PA10 6.5 ammo issues

[Jmccracken1214]

Running a Gen 2 pa10 with a BA 6.5 18” barrel, mid length, with a jp adjustable gas block and CMC Trigger.


I was running 42.8 of h4350 with berger 140 cci 450 primers in bolt guns, turned it back to 41.7gr, tried some in the AR today, and had some weird issues
Only shot 10 rounds but I had 1 very light primer strike, barely made a mark on the primer, and the rest of them were cratering pretty good with a few pierced.

I will turn the load down to 41gr and try but I felt like this was nowhere near hot enough to be doing this to the brass?

 

[LRRPF52]

Firing pin aperture allows primer cup material to flow into it on most AR-10s. I’ve seen this condition regularly over the past 2 decades.

It’s the reason why JP makes their bolts and firing pins the way they do.

AI bolt guns have/had the same thing with the large FP aperture for reliability.

On one of my .260 Rem ARs, when I disassembled it, primer material was wrapped around the firing pin shaft in little rings.

Not good.

A guy made an enlarged firing pin for me to test, which seemed to address the problem.

I haven’t shot much .260 Rem since then though due to how short my brass life is in the gas gun.

 

[Jmccracken1214]

Firing pin aperture allows primer cup material to flow into it on most AR-10s. I’ve seen this condition regularly over the past 2 decades.

It’s the reason why JP makes their bolts and firing pins the way they do.

AI bolt guns have/had the same thing with the large FP aperture for reliability.

On one of my .260 Rem ARs, when I disassembled it, primer material was wrapped around the firing pin shaft in little rings.

Not good.

A guy made an enlarged firing pin for me to test, which seemed to address the problem.

I haven’t shot much .260 Rem since then though due to how short my brass life is in the gas gun.

About once a year, I run back to large frame ar’s and then sell due to finicky stuff..,, then about a year or so later, find myself back again

 

[bigjake83]

Running a Gen 2 pa10 with a BA 6.5 18” barrel, mid length, with a jp adjustable gas block and CMC Trigger.


I was running 42.8 of h4350 with berger 140 cci 450 primers in bolt guns, turned it back to 41.7gr, tried some in the AR today, and had some weird issues
Only shot 10 rounds but I had 1 very light primer strike, barely made a mark on the primer, and the rest of them were cratering pretty good with a few pierced.

I will turn the load down to 41gr and try but I felt like this was nowhere near hot enough to be doing this to the brass?

Your loads are to hot, I'm running 40.8 of H4350 under a 140 ELD and getting 2720fps. And I have absolutely no pressure signs just a slightly flattened primer.

 

[Jmccracken1214]

Your loads are to hot, I'm running 40.8 of H4350 under a 140 ELD and getting 2720fps. And I have absolutely no pressure signs just a slightly flattened primer.

I may offload this. I have a few 6.5 bolt guns that run the same load good. I don’t like having to make up multiple recipes for the same caliber.
Ugh.

 

[LRRPF52]

If I had a .260 Rem bolt gun, it would allow me to get more loads per piece of brass than my gas-operated rifle.

You can really push .260 Rem in bolt guns.

One of the big complaints from guys who used to shoot 6.5 Panther or 6.5-08 wildcats was that the .260 Rem would be “handicapped” when it got SAAMI approval. With not many ways to determine actual chamber pressure back then for the hand-loader, and using mostly 700 actions, they were chasing 6.5x284 speeds with no real warning signs other than the obvious velocity, and getting away with it.

 

[bfoosh006]

You might try a different firing pin. I bought a handful when they were cheap, and the tip sizes varied by enough to allow a better fit if need be.

 

[FALex]

I haven’t shot much .260 Rem since then though due to how short my brass life is in the gas gun.

LOL...here, here. I just buy the cheap shit and know it's going to be loaded once. .260 SRP brass is not readily available right now, but maybe at some point. That would change this dynamic considerably.

 

[bigjake83]

LOL...here, here. I just buy the cheap shit and know it's going to be loaded once. .260 SRP brass is not readily available right now, but maybe at some point. That would change this dynamic considerably.

Or you can come over to the Dark Side with all of us 6.5CM Shooters

 

[rpoL98]

does your PA-10 come with what is referred to as the "HP" or skinnier firing pin? I think the skinny ones are about 0.067" - 0.070" at the tip, compared to the 0.078" - 0.080" for a normal AR-308 .308 firing pin. I think those are the ball-park numbers, just going from memory.

the skinnier FP comes with the reduced aperture in the bolt face, obviously.