Survivalist Forum banner

AR gas ring issue

3K views 43 replies 13 participants last post by  Unobtanium 
#1 ·
Had my first issue with the gas rings on one of my AR pistols yesterday. In about 50 years of shooting these things, this was something new.

Was cleaning the gun and went to take down the bolt, and the bolt would not move back in the carrier so I could get the cam pin out. It would move back and forth a short distance, but not easily. I ended up hammering it back into the carrier with a plastic screwdriver handle to get the pin out.

Turns out, one of the gas rings somehow got out of its slot and got wrapped around the back of the bolt and was tying things up.

Shot 100 rounds out of it and the gun was shooting fine with no sign or hint of problems. I clean and inspect them after every outing, and everything looked/felt normal at the last cleaning.

Luckily, I had some spares in my little backup kit, and it was an easy enough fix, took about 5 minutes to swap them out. If you dont already, may want to add a set to yours. Something small and "pointy" in there too, to help get them out, would be a good thing too.

Awhile back here, there was a discussion about cleaning your guns and a number posted that they normally didnt, and why bother. Those who dont are more than welcome to do as they see fit, but its things like this that emphasize why I think you should be cleaning and inspecting them, at least regularly.

If I hadnt done my routine maintenance, this would have gone undiscovered, and who knows when it would have choked the gun. I know how things go for me, and it would have done so at the worst possible moment.

Theres more to cleaning than just "cleaning", its inspecting everything as your doing it, looking for, and addressing things like this that might pop up.
 
See less See more
#10 ·
This sounds like possibly a rough carrier ID causing premature wear, or maybe it's over-bored. This should not be possible with proper tolerances and surface texture, but can happen if either is amiss.

The rough texture could cause the rings to wear thin, and the ends become "little points" and can wedge as you describe as they spring out of the channel they ride in and are pinched between the bolt and carrier ID, as they are now thin enough.

Hard to explain, easy to show/visualize.
 
#12 ·
That would be best, but also...the other 2 rings? How did THEY look? For reference, I took a micrometer to my gas-rings, and their "depth" had not changed to 0.001+- from when new, as compared to a Colt gas ring, after 2000+ rounds. You should see ZERO wear on a gas-ring, minus surface polishing of t he bearing surface, at 1K rounds unless it was full-auto suppressed on an SBR or something. Were your other 2 rings "thinning" in depth? If so, I'd probably replace the carrier now, 'cuz that ain't right (and my bet is more on the carrier than uber soft rings).
 
#19 ·
Did they pass the casual eyeball? Maybe you had a dud ring or something. Keep us updated
Yea, they didnt look any different than the ones that replaced them.

So was a PSA bolt? Premium or other is its a PSA?
Its a PSA BCG. Not sure if its a "premium" or not. It is chrome lined, and has their logo on it.


Dont know if its relevant or not, but about half the rounds through the gun were suppressed. There is a noticeable difference in ejection pattern suppressed ( around 1:00) vs unsuppressed (around 4:00). I really dont notice any difference shooting the gun(s) one vs the other, other than its is gassier (in your face) with the suppressor mounted.
 
#20 ·
Yea, they didnt look any different than the ones that replaced them.


Its a PSA BCG. Not sure if its a "premium" or not. It is chrome lined, and has their logo on it.


Dont know if its relevant or not, but about half the rounds through the gun were suppressed. There is a noticeable difference in ejection pattern suppressed ( around 1:00) vs unsuppressed (around 4:00). I really dont notice any difference shooting the gun(s) one vs the other, other than its is gassier (in your face) with the suppressor mounted.
I've fired thousands of rounds suppressed. In fact, the gas rings I measured, were used in a mostly suppressed gun. It shouldn't really matter that much. NOTHING about your usage should cause the gun to eat rings every 1k rounds, IMO. Although with full-auto, suppressed, they won't last as long, I'd still be wanting answers if they were dying at the 1k mark.
 
#24 ·
Was wondering about the bolt quality. Most of us would assume a quality bolt has quality rings and so forth
I have two more PSA builds using the same BCG. No problems there so far. One of those is the gun I've been shooting the most of the three, and it's got around 5000 or so rounds through it at this point. I'll take a closer look at it.
 
#25 ·
Google - McFarland gas rings. I have two that I've never tried yet, but they're pretty cool.
I stagger the end gaps in the gas rings when I reassemble the bolt, it's probably unnecessary but I do it anyway. The McFarland piece is a spiral that makes three "layers" of gas ring when installed so there's no real end gap.
 
#26 ·
Staggering isn't necessary, and CRANE dropped the McFarland because they had tolerance issues and caused more issues than they solved. If you want to try the 1-piece deal, I have had good luck with JP's version of it. In multiple BCG's, they work very well. I have not heard of anyone having an issue with them like the McFarlands, either. It was so bad that people began only buying McFarland's from G&R, as Grant alleged that he mic'ed each set that went out, lol
 
#32 ·
Just got back from the range. Put 100 rounds through it and no problems. Everything looks normal when I popped the BC and stripped it. Ill look at things closer a little later here when I clean it. Doubt Im going to see anything though.

I keep hearing that there will be trouble if the gaps in the rings are lined up, but Ive never found that to be the case. I see it on a pretty regular basis on all my guns when Im cleaning, and I assume they were lined up at some point while shooting, and there were no problems. Most of those guns have a lot of rounds through them too, and are still on the original rings.

Im going to have to call my buddy who has an old M16 and see if hes ever had a problem related to this. Ill ask him if hes changed them out on his. Im thinking not though. Over the years, we've shot a bazillion rounds through that gun in FA, and I cant ever remember it having any kind of function issues or problems, at least when I was present or shooting it. Been awhile since Ive seen him or the gun, might could have to grab a case or two of 5.56 and 9mm and go down and see him. Stress relief is always fun. :)

I never heard of any of this until the internet popped up and always just figured it was internet lore or over worrying on things that really werent an issue. Im assuming what went on here was just one of those random mechanical things, and not really a problem. Im just going to keep shooting this gun for a couple of months and keep an eye on things and see what happens. Im not thinking anything will, but you never know.
 
#34 ·
Had a brand new S&W M&P-15 that chewed up a couple of rings around 1K rounds. I never figured out what caused it but the rifle would still run. I went with a single piece ring and have no issues with it at all for about 5K rounds now, still running strong.

Just as a general question, how long should the gas rings last on a AR-15 that lives life in semi-auto and rarely goes into mag dump mode?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top