Also is the bc, with bolt extended on the table to see if it collapses a good test?

Thanks.

Yes,   Every time you clean your AR, stand the BCG up on the bolt face.

If it slides down, your gas rings are worn and time to replace.

I have been using the Brownells one-piece rings for a long time. FOR ME, they have worked very well.I usually clean my ARs every thousand rounds or a little sooner if they start acting up. ymmv

I have seen Ar's work just fine with some pretty messed up ring sets.

I suppose the answer strongly depends on how you use the gun . If it is a range toy shoot it until it stops working . If you count on it for defense of family and home all aspects of maintience need a closer look.

Gas rings are something everyone should have as spare parts

As I recall, the Colt armorer's test is to remove the cam pin and pick up the carrier, bolt down.  If the bolt falls out, it's ring time.

Many NEW bolts and carriers will fail the "stand it on the bolt face and see if the carrier falls on the bolt" test.

I don't even bother to look unless I'm having any kind of malfunction.   A failure to cycle can be due to worn out gas rings.

Didn't know this.

You're not really describing a problem. You're just describing an action and then doing something based on those actions. Sort of like saying everytime you fill up for gas, check your tires and replace as needed. Would that be true? Entirely possible, but in all likelihood not.

It all comes down to how much you use your rifle. You don't change your car tires out like NASCAR does when they make a pit stop because you're not a race car driver. You don't change your gas rings out everytime it fails a drop test for the very same reason.

I have several bolts that fall on its face. Some do, others don't. I only had to replace gas rings once when it once cracked off.

Should you check it each time you clean? Yes.

Most likely prior to your gas rings failing, most likely your buffer spring would wear out.

Again all depends on how much you shoot. Are you running and gunning it every time you take it out? Do you go to a high round count class? If so, then yes, by all means you should be swapping out springs and gas rings at a set interval. You'll eventually figure out when it is time to do so. As a regular joe who goes to the range to shoot 180 rounds over the span of an hour? Probably not.

You are correct. The table test is wrong. On another note I have removed the gas rings and the rifle operated several thousand rounds without problem. I don't recommend doing this but others have done it as well.

There is some discussion in the Hendersen Defense thread about worn gas rings potentially leading to premature wear on the upper receiver.

Hendersen Defense Page 27

Uhhh, no.

Check bolt assembly for proper fit with bolt cam pin removed. Turn key and bolt carrier assembly and suspend the carrier so the bolt assembly is pointed down. The bolt assembly must not drop out. If weight of bolt assembly allows it to drop out of key and bolt carrier assembly, replace bolt rings.

The rings must hold the weight of the bolt assembly up not the weight of the bolt carrier assembly, which is about 3x heavier.  You are replacing rings more often that needed.

The majority of AR owners do not shoot enough to ever worry about replacing there gas rings.... OP's post count is proof of that....

Those that do...already know how to check them..

Ring life seems to be highly variable between weapons.
Typically I would expect at least 5k, but would not be surprised if it was less although I have not seen less in my weapons.
The test by the military TM is the rings must support the weight of the bolt not the bolt carrier.
Essentially I check the rings, ejector, extractor, and check the bolt for cracks every time I clean it.

I wonder if there could be a college course on the effect of the AR15 markets on new buyers? There are more maintenance items for an ar15 than any other weapon that I know of. Heck people here sound like they take better care of their ar15 than they do of their car!

Nearly every part on an ar15 is somehow tied to specific round counts. If you shoot 5k rounds, your entire gas ring needs to be replaced. Shoot 10k rounds, replace this, replace that, replace everything.

Now if you really want to hear a crazy maintenance schedule, pull out a Desert Eagle manual. They want you to buy a 50 bucks part kit every 2 years or after just 3k rounds!

Point is, you don't need to do it. Just ignore it and use your own judgement on what sort of round count you'd need. Just keep in mind that when panic sets in, or if the political landscape changes, these parts will become gold overnight.