Mrgunsngear: Palmetto State Armory 10.5'' Nitride 5.56 AR-15 Pistol: Best Truck Gun?

[1168]

And what will that mean?

Nothing, as long as you aren’t using any muzzle devices that require shims or peel washers. Just a possible explanation for why the OD of the crush washer looks barely tightened.

If you do try to put a mount on it, or a brake that requires shims, you will find that 1/2” washers/shims won’t seat on the shoulder. Assuming it has the false shoulder, and every PSA barrel I’ve inspected does.

[Doc Safari]

Nothing, as long as you aren’t using any muzzle devices that require shims or peel washers. Just a possible explanation for why the OD of the crush washer looks barely tightened.

If you do try to put a mount on it, or a brake that requires shims, you will find that 1/2” washers/shims won’t seat on the shoulder. Assuming it has the false shoulder, and every PSA barrel I’ve inspected does.

So if I'm reading this correctly, a Smith Vortex that doesn't require either a shim or crush washer would be GTG, but another muzzle device that requires either would not?

[1168]

So if I'm reading this correctly, a Smith Vortex that doesn't require either a shim or crush washer would be GTG, but another muzzle device that requires either would not?

It is possible that it won’t seat on the shoulder. If thats the case, it’ll be super obvious if you try it.

[tehpwnag3]

The Vortex has a recessed area with a rim that will extend over the barrel shoulder slightly. Inside that recess is what should make contact with the barrel shoulder. If I'm tracking 1168 correctly, it's possible that the muzzle device will stop against the false shoulder instead. Correct me if I am wrong.

images.jpg

So if I'm reading this correctly, a Smith Vortex that doesn't require either a shim or crush washer would be GTG, but another muzzle device that requires either would not?

[Doc Safari]

And can somebody find or post a pic of this false shoulder. I'm not sure I know what everybody is talking about.

[1168]

And can somebody find or post a pic of this false shoulder. I'm not sure I know what everybody is talking about.

https://imgur.com/a/qsPrZvl

Let me know if you’re able to see it. I apologize for the crude scribbling.

[Doc Safari]

https://imgur.com/a/qsPrZvl

Let me know if you’re able to see it. I apologize for the crude scribbling.

I see it. You're talking about that short, non-threaded area just as the threads end and the fatter part of the barrel begins?

Why would they do that?

[1168]

I see it. You're talking about that short, non-threaded area just as the threads end and the fatter part of the barrel begins?

Why would they do that?

Yup. And its ~9/16” in diameter vs 1/2” of the threads.

The why is the part that baffles me. Is it a cheaper way to cut threads? I don’t know. Seems unlikely. It also baffles me that this is not readily found by internet searches. Surely, I’m not the only one that notices stuff like this. It was blatantly obvious, immediately, when I tried to upgrade the muzzle device. I’ll have to take some pictures of the barrels on display next time I shoot at PSA.

[Doc Safari]

Yup. And its ~9/16” in diameter vs 1/2” of the threads.

The why is the part that baffles me. Is it a cheaper way to cut threads? I don’t know. Seems unlikely. It also baffles me that this is not readily found by internet searches. Surely, I’m not the only one that notices stuff like this. It was blatantly obvious, immediately, when I tried to upgrade the muzzle device. I’ll have to take some pictures of the barrels on display next time I shoot at PSA.

Well, in a way it saves me the trouble of putting an aftermarket muzzle device on it. Guess I'll have to put the Smith Vortex on the BCM upper if I go that route.

[1168]

Well, in a way it saves me the trouble of putting an aftermarket muzzle device on it. Guess I'll have to put the Smith Vortex on the BCM upper if I go that route.

If it doesn’t play nice with the Vortex, you can probably just bump the shoulder forward with some 9/16” shims. I used a slightly reamed Griffin M4SD overtravel stop to bump the shoulder forward, because I had a few on hand. But try it, it might go on properly if the threads are recessed a bit. Just check alignment before firing.

Not necessarily directed at Doc Safari:
Obviously, anyone seeking to eff with mounts on a shoulder like this should seek advice from a competent gunsmith and/or check alignment before firing. Maybe consider a .30 cal can. Don’t blame me if you wreck an endcap on your $1,000 silencer after mounting it to your $499 rifle.