Dented brass... is this a problem?

[geckocavemen]

Hello all, this is my first AR and I built the lower, which is a Bushmaster receiver with a PSA lower build kit and an H buffer. The upper is a PSA premium with FN barrel and mid length gas system. The ammo is Federal 5.56 xm193. Ejection is at about 4:00 and the brass flies ten feet or so.

I've done a lot of research and I don't think I have any problems but I wanted to ask just to make sure. The brass is hitting the deflector and getting dinged pretty good just behind the shoulder and I wanted to confirm here that it isn't over gassed. I've included pictures of the brass and also the deflector so you can see where the impact is occurring.

Finally, I'm still not entirely clear what the signs of over gassing are. I know if rims are getting ripped it's a sign but is there anything else?

[Onyx Z]

The rim of the case getting ripped off is not a sign of over-gassing. It's a sign of over-pressure ammo. Two entirely different things.

[markm]

Neither of those is a sure sign of over gassing. I'd try an H2 buffer at a minimum. I only run H buffers on BCM 14.5 middies because their port is a little smaller. An H2 or H3 will likely improve things. The shoulder dents aren't a deal breaker, but it'd be nice to minimize that. I can see some extractor claw marks on the rims, but with the lighting it's hard to see if they're excessive.

HEAVIER BUFFER!!!

[geckocavemen]

I'll get an H2 buffer and see how that improves ejection and the extractor claw marks. Almost went with that originally but decided not to at the last minute.

Just for my personal knowledge, what are some signs of an over gassed AR?

[markm]

It's really a feel thing. Rate of fire in full auto is a sure way to measure, but very few of us have that readily available.

Ejection patterns and stuff can give you an idea, but they're not 100% reliable. It sounds like you're not too bad if the brass is flying backwards.

[Lincoln7]

I recommend picking up an H3 buffer as it comes with 3 tungsten weights. In the event it doesn't run with that (my guess is it will run well) you can swap one of the tungsten weights out for a steel one making it an H2.

Or, since it's cheaper, buy the H2 and swap the one tungsten weight out of your H buffer to make the H2 an H3. Now, if only someone would sell the correct size tungsten weights...

[BufordTJustice]

I recommend picking up an H3 buffer as it comes with 3 tungsten weights. In the event it doesn't run with that (my guess is it will run well) you can swap one of the tungsten weights out for a steel one making it an H2.

Or, since it's cheaper, buy the H2 and swap the one tungsten weight out of your H buffer to make the H2 an H3. Now, if only someone would sell the correct size tungsten weights...
I agree. H3 at least. My wife used to run the OP's barrel in the 14.7" length and, before upgrading to a BCM, she ran a Vltor A5H4 buffer.

[geckocavemen]

Update: The weather finally cooperated and I was able to get out and try the H2 buffer today. It worked well and the dings on the brass were much less noticeable. Ejection was at 4:30 and the brass consistently flew about 10-12 feet. The bolt locked back every time as well. I was shooting Federal xm193.

I'm pretty happy with where its at now and gonna pass on an H3 for the time being. I'm afraid if I went with that the barrel would dip a little too much as the bolt returned forward. Below is a pic of some of the brass from today.

32241

[O3SKILL]

Looks like it's over gassed to me. Run some commercial .223 through it and I'd wager you won't see any more dents. I had the same issue with a factory Rifle I purchased firing Winchester M855....it was so over gassed and ejecting/extracting so violently that it was leaving massive dents in my brass from banging against the back of the ejection port. I was told to run a heavier buffer as a band aid, but decided to just send that humpty dumpty back. There is no reason a mid-length gassed Rifle shouldn't run properly with a H-buffer firing full power .mil loads. Unless of course the gas port is too big and it's getting too much gas.

[Iraqgunz]

I'd love to know how premium that gas port size is?

[TacticalMark]

I'd love to know how premium that gas port size is?
Their 14.5-14.7" Midlength PSA FN Barreled 2013 era are .082 observed on a friends rifle. I'm sure that the 16" is on the large side as well.

[markm]

Their 14.5-14.7" Midlength PSA FN Barreled 2013 era are .082 observed on a friends rifle. I'm sure that the 16" is on the large side as well.

.080 is the top end for 14.5 middy in my experience. When you get over that .080" range, you've given up all the smoothness of the middy. My middy, at .080 feels no different than a carbine.

[geckocavemen]

I don't know what size the gas port is on my 16" mid and unfortunately don't have the tools required to find out. I think it's safe to say it's on the large side though. I ordered a Sprinco blue buffer spring today and I figure it will still work fine.

[BGREID]

All that brass is reloadable.

[geckocavemen]

Final update: I installed a sprinco blue buffer spring and the rifle functioned fine with both .223 and 5.56 ammo today with the H2 buffer I already had. The dents on the 5.56 brass were almost nonexistent and the bcg locked back each time with the .223. I feel this is a good combo for my rifle and perhaps any PSA middy. It's a bummer it's so overgassed from the factory though.