Changing AR-15 Gas rings

[Dr.Zubrato]

How often do you change your gas rings if at all?
I've read some change their gas rings every 3-5k rounds, whenever the BCG fails the bolt carrier group test, or never.

I've only put about 2-3k rounds through my AR, and my bolt fails the bolt carrier group test. No difference in function, but it sort of worried me.

I highly doubt the military changes their gas rings at such low round count intervals, or that it makes much of a difference, with BCG's working with only a single gas ring installed.

I've read some folks say it wont make a difference, but change it anyway just in case, but of what? Short stroking? To be honest I've almost never heard of an AR short stroking due to gas rings that weren't broken, or missing in some way.
More often it's the gas block, which I assume more people switch out than gas rings.

Any opinions, or experiences?
Thanks!

 

[HoosierQ]

What is bolt carrier group test? I Googled it and saw a lot of ads but no object test criteria.

 

[taliv]

it's never the gas block on a properly built gun. the gas block isn't a wear item. it either works from the beginning or it doesn't.

the gas rings will eventually wear because you are basically scraping them back and forth with every shot.

i imagine how many rounds of life you get depends on your firing schedule, and how often you clean it and how much lube you use.

the rings aren't a lot of money so i would say if reliability is important to you, go ahead and change them. if it's just a range toy and you're a little lazy like me, no real harm in shooting it until it fails and then changing them.

 

[rcmodel]

The test is:
Pull the bolt forward in the bolt carrier and stand it up on the bolt face.
If the carrier slides down over the bolt from it's own weight?

The rings are worn out and not providing any seal tension inside the carrier.

Time to replace them.

rc

 

[cfullgraf]

What is bolt carrier group test?

The test I know of for checking the condition of the gas rings is as follows...

Remove the bolt carrier group from the firearm, clean and reassemble.

Pull the bolt to its forward extreme.

Stand the bolt carrier group on a table on the bolt face.

If the bolt carrier slides down the bolt on its own, the rings should be replaced.

There may be other "tests" but I have not heard of any.

 

[Dr.Zubrato]

@ Taliv: I understand the gas block is not a wear item, but meant more people probably incorrectly install their own (lopro) gas blocks which would be a more common cause of short stroking, than worn gas rings.
Sorry for the confusion.

I keep the bolt/BCG well lubed, and I didn't think I'd have to do this for at least another 1-2k rounds, so I'm a little dissapointed, but I kinda get it, I don't run it often but I do run it pretty hard.

Out of curiosity, I'm kind of wondering if the bolt carrier group test is the gold standard, considering different BCG weights, as in semi-auto, full auto, lightened BCG's and different materials.

 

[taliv]

it's just a guideline. don't get hung up on it. pull the dang thing in and out with your fingers. do you feel a reasonable amount of friction? if not, you aren't getting a seal

 

[Dr.Zubrato]

gotcha, I'll be looking into some new gas rings. Thanks!

 

[briansmithwins]

The test form the TM is to leave the cam pin out and turn the bolt carrier bolt down. If the bolt falls out under its own weight the gas rings require replacement.

Using the weight of the bolt carrier works too but is going to cause you to replace the rings earlier.

The real question is: Are you having failures to cycle like short stroking? If not, don't worry and be happy.

BSW

 

[Walkalong]

Cleaning and lubing first makes sense, cause enough crud would hold it in. Learned something new.

 

[HoosierQ]

The test is:
Pull the bolt forward in the bolt carrier and stand it up on the bolt face.
If the carrier slides down over the bolt from it's own weight?

The rings are worn out and not providing any seal tension inside the carrier.

Time to replace them.

rc

Thanks!

 

[TrickyDick]

If you're really concerned about it, you could change it over to a piston driven system. but new rings are way less expensive and not hard to change.

 

[rcmodel]

If you're really concerned about it, you could change it over to a piston driven system.

And just replace one minor gas ring maintenance problem with a major wear problem from bolt carrier 'tipping', and non-standard, expensive parts!

rc

 

[MistWolf]

If you're really concerned about it, you could change it over to a piston driven system. but new rings are way less expensive and not hard to change.

You mean I could eliminate the need for piston rings by getting a... piston?!?

 

[chicharrones]

You mean I could eliminate the need for piston rings by getting a... piston?!?

Diesel rings vs. gas rings, or something like that.

 

[Dr.Zubrato]

Briansmithwins, I just checked the TM for the M4 and you're right!
Indeed, thats how the military does it, and I'm saving the TM package for future reference, I didn't even think to check there!

I've always read the bolt rings had to support the bolt carrier assembly, but it seems I'm OK. I will be getting new gas rings for future replacement however, better to have and not need, than need and not have.

I'm not having any problems, or at least not yet. Just doing some pre-range checks before I go out in the boonies for some run n gunnin, and wanted to make sure it won't go down in the middle of it.

No piston guns for me, unless I'm running a 7" SBR suppressed, which god willing, someday I'll be able to afford!

 

[zoom6zoom]

The rings are cheap. If it makes you feel better to change them, go ahead.