PSA 300blk out of spec chamber or what?

[ARKEMAXUS]

Could use some other opinions here please...
Against my better judgement I bought a PSA 300blk upper as my buddy swears by his. Already have a BCM that's been good but wanted a 1/8 twist for supers. Long story short, took it to the range yesterday and noticed something strange; the beginning signs of case head separations on EVERYTHING I shot out of it. (Some 90 rounds) Didn't matter if it was factory or my loads. MY BCM doesn't do this, I double checked, cases fit right back in my LE Wilson gauge after firing just fine. Not so witht he PSA. So what do you think? Out of spec chamber or what am I missing here?? Thanks for looking.

-Case on the left is what all look like after shot out of BCM, case on right is what all look like after firing through PSA

 

[6.5SH]

I'd think wildly over gassed for your recoil spring/buffer combo or possibly a bad chamber.
I had a 6.5 Grendel pistol upper from them that was just garbage. Don't do what I did and try to fix it, contact them and send the pics and explain the same lower works on another .300 BO upper.
They will take care of it. Is disappointing that we have to send stuff back, but they seem to run their reamers and other tooling way past it's useful lifespan. Assembly also seems to be luck of the draw with them.

 

[FuhQ]

I'd say most-likely chamber is out of spec, but as was pointed out, wildly overgassed and incorrectly weighted buffers can also cause some similar/weird issues with AR's. But in this case, i'd put my money on a bad chamber. Have them swap in a new barrel (that they've physically checked the chamber on before install), and a new matching headspace bolt, and you should be good to go.

Being that it's .300 BLK, i'd see if they'll let you pay to upgrade, and swap you in a Superlative Arms or Seekins adjustable gas block while they already have it torn apart. Worth asking... Especially if you run it suppressed, or plan to in the future...You'll want an AGB. Mine runs great with a standard gas block, but in the near future I will be swapping in an AGB just to clean up some of the excess carbon blow-back inside the receivers to help keep the gun and bolt clean.

 

[supercorndogs]

Why 1 in 8 twist for supers?

 

[ARKEMAXUS]

O.k. glad I asked. Not sure why I hadn't thought to try the lower that I run the BCM on. I'll go try that this afternoon and report back. Thanks for your replies.

 

[ARKEMAXUS]

Why 1 in 8 twist for supers?

Because I've found 1/7 way overstabilizes my 150 supers. It took me a long time to figure out why I couldn't get an accurate supersonic load. From day 1 of load developement my 225 subs grouped just fine but my 120s and 150s in supersonic were all over the place no matter what powder charge, seating depth or case/primer combo I used. Finally figured it out when I tried them in my buddy's 1/8.5 twist and groups were way better.

You ever play with the Berger stability calculator? Some guys have struggled for years to find a supersonic load their 300blk likes only to find out their issue was pairing the bullet with the right twist rate.

 

[ARKEMAXUS]

Just got back from the range. Ran this upper with the lower from my BCM 300blk. Ran it with the same bolt and then with the bolt the upper came with from PSA. 3 different kinds of factory ammo and then 3 different handloads. All had the same result; this chamber is out of spec. Pretty infuriating.

 

[Shoots 700's]

Not surprised, bargin barrel.

 

[Gentleman4561]

I will buy PSA lowers all day long, but one can’t expect much from a $55 barrel. The nice thing is that they will fix it for ya!

 

[tomme boy]

Thats what happens with a reamer that is held rigid and was not centered properly and ran in too deep. They really screwed the pooch on this one. Looks like the reamer was a little large in the web area as well. But that could be from reaming too deep.

Ask them for some brass you ruined. They are making brass and ammo now and i would ask them.

Go over to ar15.com and go to the industry section and put a post to ask Jerimiah. He is the PSA guy and will get you taken care of. Don't bother with the website or calling.

 

[ARKEMAXUS]

Thats what happens with a reamer that is held rigid and was not centered properly and ran in too deep. They really screwed the pooch on this one. Looks like the reamer was a little large in the web area as well. But that could be from reaming too deep.

Ask them for some brass you ruined. They are making brass and ammo now and i would ask them.

Go over to ar15.com and go to the industry section and put a post to ask Jerimiah. He is the PSA guy and will get you taken care of. Don't bother with the website or calling.

I'll check into that, thanks Tomme.

 

[ARKEMAXUS]

Not surprised, bargin barrel.

Yeah, it's amazing to me. I ALWAYS buy the best gear (buy once cry once right) and decided to make an exception this go around and it bit me in the ass. Never again.

 

[Mike_in_FL]

Yeah, it's amazing to me. I ALWAYS buy the best gear (buy once cry once right) and decided to make an exception this go around and it bit me in the ass. Never again.

Not necessarily pointed at you OP, but what amazes me is that people complain about or won't use the PSA warranty. But everybody here LOVES Vortex scopes cuz the warranty. Funny you don't see more really bad barrels from PSA since the barrel shop used to make chopper parts.

 

[Jgault]

They do seem to have a good warranty but their ups bill must be astounding.

 

[ARKEMAXUS]

Not necessarily pointed at you OP, but what amazes me is that people complain about or won't use the PSA warranty. But everybody here LOVES Vortex scopes cuz the warranty. Funny you don't see more really bad barrels from PSA since the barrel shop used to make chopper parts.

No, I agree, I've always said the same thing about Vortex.