AR BCG question...

[44Blam]

I bought a bold carrier group from Wilson Combat and it came with the BCG and a little plastic bag with an o ring....

What is that O ring for???

I've never seen an o ring anywhere near a bcg...

[M-Tecs]

It's a mod for the extractor to increase force. It goes around the extractor spring for claimed increased reliability.

https://kmtactical.net/product/ar-15-extractor-o-ring/

https://www.ar15.com/forums/ar-15/-/118-537065/?

[Lloyd Smale]

I use them in all of my ar15s

[popper]

Probably a spare or 'use if needed'. thoughtful Bill. I don't know if any of mine have it on the spring or not, never have had a problem.

[mvintx]

I have some that have the O-ring. I have some without an O-ring. For me, they just make it harder to insert the extractor retaining pin.

[44Blam]

I've always bought my barrel/bcg together at gun shows where I can make sure that it'll work. Those guys almost always have GO NOGO dummies and you can sick that in the barrel and see if your bolt locks up...

Now I've got to take those things apart and see if I actually have O rings in them...