How do you know?

[shootstraight57]

How do you know when the gas rings on your AR-15 are worn?
Despite the obvious function reasons how can you tell by looking at them that they are worn?
I recently had a friend of mine look at my Colt Match Competition AR-15. He stripped it down to the bolt carrier group and stated that the gun was shot alot and that the rings are worn.
I have never had any functional problems with the rifle and to date probably fired 500 rds through it since I purchase it 5 years ago.
I am dumbfounded! Without physically measuring them with a micrometer how can you tell?
I read that the AR rifle can operate with only one gas ring. The rifle has a 20" barrel and chambered in .556
Any input from the community will be helpful

 

[Tommygunn]

A standard "rule of thumb" test is to take the assembled bolt carrier group and twist-pull the bolt out as far as it will go, then place the assembly down vertically on a flat horizontal surface, boltface down.
If it stays up the gasrings are OK. If, however, the carrier slides down due to gravity, then it's time to put some new gasrings on the assembly.
There might be more precise ways but that's the most basic one given.

 

[shootstraight57]

Thanks for the info. That would be a quick reference to the condition of the rings.
I knew someone in the community would have an answer.

 

[briansmithwins]

500 rounds is broken in, not shot a lot.

The TM calls for holding the bolt carrier bolt down, with the cam pin out. If the bolt falls out under its own weight, replace the gas rings.

A badly made bolt carrier with rough machining marks or burrs might damage gas rings at 500 rounds but that doesn't sound like the case here.

BSW