AR 15 Gas Ring Failure

Status
Not open for further replies.

DustyGmt

Member
Joined
Nov 7, 2016
Messages
3,995
Location
Green Mountains
I know that gas rings are among one of the parts that occasionally need replacement after so many rounds from normal wear and tear but is it common for them to break in this fashion?

I noticed my bolt was moving too freely inside the carrier and figured they were starting to wear, a quick estimate being probably around 5k through this carbine. I tend to run this carbine a lil harder than my others. I have actually never had to replace a part on any AR's but I guess that time has come and I was just wondering if this breakage is just par for the course and if 5k rounds was a typical round count for gas ring replacement?

I know I fired approx 100 rounds after this failure with the gas rings, wanted to see if it would function properly and it did. If you look at the pic you will notice it's one ring that's broken and sheared off to form a sharp point. IMG_20191103_213448.jpg
 
Who’s rings went into your bolt at birth may be anyone’s guess but they are a wear item as you point out and ultimately are critical for function.

I was taught to check them when removing the bolt for cleaning, then proceed as follows after reassembly:

1. Depress the bolt and hold the carrier vertically, bolt down. If the bolt moves forward the rings need replaced.
2. If not, extend the bolt, set it on the bench vertically (bolt down) and if it retracts from the carrier’s weight slowly, then it’s time to purchase replacement rings to have on hand.

I prefer using the unitized assembly and not having to stagger them myself because I’m lazy like that. For the record I’ve replaced worn gas rings but never broken any.
 
Last edited:
That's not exactly common but not really unheard of either. Like you said gas rings are a wear item so no big deal if they need replaced. A friend of mine broke a gas ring like you did and somehow it wound up in his lower and it jammed up the trigger mechanism. Took him a little while to figure that one out lol.
 
Who’s rings went into your bolt at birth may be anyone’s guess but they are a wear item as you point out and ultimately are critical for function.

I was taught to check them when removing the bolt for cleaning, then proceed as follows after reassembly:

1. Depress the bolt and hold the carrier vertically, bolt down. If the bolt moves forward the rings need replaced.
2. If not, extend the bolt, set it on the bench vertically (bolt down) and if it retracts from the carrier’s weight slowly, then it’s time to purchase replacement rings to have on hand.

I prefer using the unitized assembly and not having to stagger them myself because I’m lazy like that. For the record I’ve replaced worn gas rings but never broken any.
Same tests I use and was taught as an Armorer. Of course, I always had the parts on hand then, I should probably get some next Midway order.

I once read somewhere that the AR-15 has 3 gas rings that don't need to be staggered and the gun can function on one gas ring if needed. 3 is just a redundant feature.

Yeah, that's not what they taught at Armorer School. They do not need to be staggered, true, and maybe will function just one; as DustyGmt's experience shows, they certainly will work on 2 and part of one stuck out. Maybe there'll be some time where one of us will either choose to, or will have to, test that, but it isn't going to be me. If one follows the routine Skylerbone outlined above, and keeps these expendable parts on hand, (hey, they even fit inside the Magpul pistol grips) there needn't be any worry.
 
Yes, they fail with wear, but 5k is a low number for this to happen IME. Gas rings were replaced on ALL M4's and MK18 uppers in my old unit prior to any overseas deployment, without question.
Are you referring to the m4's you trained on prior to deploying. The weapons you trained with went with you on deployment? Just curious?
 
My first duty rifle at work was a Bushmaster. That thing would eat gas rings like it was going out of style. If I remember correctly I was on my 4th set when I got a replacement rifle. The Bushmaster was 4 years old and had around 8-10k rounds through it.

My 2nd/current duty rifle is a Colt 6920 and is about 9 years old and has about the same round count. Still on the original rings.

My personally owned Colt/BCM rifle just killed a gas ring a few weeks ago. Probably around 6-7k rounds. However I hadn't cleaned the rifle (up until a few weeks ago) in over 3k rounds with much of those suppressed. So that probably shortened the life a little bit.
 
I'm probably around 6k through my 6920 and no problems yet there.

A troy 18" that I traded into and quickly traded off would eat rings as well. It probably had about 3-4k through the barrel.

The beater A1 DPMS has a unknown round count and is still ticking along fine.

Ar-s they're like people; some you wonder how they're still walking after the 15th car wreck, and others look good but fall apart when you look at em funny.
 
The bolt in an AR is a piston with the gas rings doing much what a car engine’s do. If a bolt eats rings the problem is likely due to wear of the chrome lining, a lack thereof, too little lubrication, or too little cleaning.

I agree there are some anecdotal exceptions out there that run and run but I would never treat my vehicles in that manner and despite my less aggressive approach to cleaning AR barrels and chambers, the BCG gets its share of attention.
 
Are you referring to the m4's you trained on prior to deploying. The weapons you trained with went with you on deployment? Just curious?
They were one in the same. Our weapons were assigned to individuals and were unit equipment, as I am sure is the case in almost every unit. Prior to deployment, ALL weapons (M4's, pistols, machine guns, sniper systems, etc.) are inspected for full serviceability, and any repairs or part replacement are performed- anything from M4 gas rings, barrel replacements, new sears on MG's, or even replacement of an entire weapon, if deemed necessary. Also, additional weapons may be issued above what is normally in the "gun lockers" for deployment if it is determined that more of a certain type of weapon(s) are required for a deployment.
 
My new Delton blew a gas ring in less than 200 rounds. I replaced all 3. The next 200 rounds blew another one. The factory wanted my rifle back for testing so off it went to Delton. IT came back with no trouble found. Since then it has not broken a ring. Go figure. Maybe the carrier needed to be broken (worn) in?
 
1) Gloves.
2) There has got to be a nasty gouge in the carrier bore from that ring point sticking out! Can you look and see?
I'll check it out when I get home. It's not chrome lined so I'm sure it's gouged at the very least. I wasnt too too worried about the carrier because I plan to replace it with a mil spec. It's the SA BCG that came with my M&P. I'm going to replace the rings though and see if it continues to run trouble free. Always good to have extra thingies arounds....
 
Premature gas-ring failure can speak to up to three issues:
Gas ring quality
Bolt dimensions
Carrier dimensions

My experience which is not inconsiderable is that it is almost 100% of the time, dismal outsized or chess-grade rings.
Look now for potential though generally insignificant scoring on the internal bore of the carrier.


Todd
 
1) Gloves.
2) There has got to be a nasty gouge in the carrier bore from that ring point sticking out! Can you look and see?
I forgot I actually do have a CL carrier, I just cleaned it up really well, first time this year and it isnt chewed up at all that I can tell. My surviving rings do seem a lil tired, though I'm not super confident I can identify out of spec vs in spec. They just seem like they have run their course because there is no resistance at all in the carrier with respect to the bolt face flat on the table test.

Time for some new rings... should solve the problem....
 
Last edited:
Oddly enough I’ve never had gas ring problems. Worn a few out after like 10k plus rounds. I used to go through the bcm bolt rebuild kits regularly
 
Status
Not open for further replies.
Back
Top