Extractor o ring ?

[Scottn]

[m16]

Shoot it without the o-ring.

If it extracts, don’t put it in.

You shouldn’t even need it if you have the black insert inside the spring.

[TKM]

Sometimes the insert melts (happens on DEs more often) but the Bushmaster upgrade is a cheap bit of insurance.

Works on Keltec 5.56 rifles as well.

[FeuerFrei]

I agree with M16 on this. I tossed them.

[Pofoo]

Does the military use them when they shoot thousands of rounds in life and death situations?
Much of internet lore is bs.

[m16]

Crane was using the “D” rings a while back, not sure if they still do.

The whole o-ring fad became a thing after that dude wrote about it in one of the Book of the AR-15 volumes.

I never use them and have never had extraction issues.

[ar15barrels]

Does the military use them when they shoot thousands of rounds in life and death situations?
Much of internet lore is bs.

No.
They use a black buffer and a proper 5 coil spring on M4's and a blue buffer and 4 coil spring on M16's.

[ar15barrels]

If the gun is properly gassed/buffered, there should not be a need for increasing the extractor tension with an O ring.
The O ring is a PATCH for a gas system/buffer weight problem.

[Epsilon]

According to combat_diver (active, 2020 special forces armorer) on AR15.com, they are not needed in semi auto.