AR Gas Rings?

[A-Smith]

I believe that's what they're called.

Three small rings fitted in a groove around an AR bolt.

What is their purpose?

Thanks in advance!

 

[Dsiwy]

Your bolt acts like a piston within your carrier and these rings provide the seal.

 

[Stevebot-7]

They prevent the gasses from escaping around the bolt, or at least slow it down . Without them you could not get sufficient pressure to make the bolt cycle.

 

[Conte]

They will wear out over time have to be replaced. Not for a while tho.
There have also been reports of AR cycling trouble when brand new rings have not broken in yet. Seems rare tho'.

And if you ever get a piston conversion kit that requires you to leave the rings in, make sure you use a worn set, cause fresh ones can be too tight for the Bolt assist spring to do it's job.

 

[A-Smith]

Thanks for the Info guys!

 

[badboybeeson]

always good to have a spare set of gas rings and other small parts
i snapped a trigger spring the other day, first time in almost 1000, ar15s ive put togeather that i have seen that.
gas rings are good for about 5k rounds
bbb