The best way is to have a qualified armorer ream the chamber with a spec 5.56 bit. If there are shavings, you are/were off spec.
That used to be the best way. Now we have Ned’s Chamber Checker (which works very well).
C4
I don’t use them, although I’m sure at least one of my guns has one in it that I’ve never bothered to remove.
I typically only recommend them if the shooter is having a problem and even then it’s a stop-gap solution. Low-powered, steel cased ammo in a tight chamber with a small gas hole, AND having extraction issues, I would try one and see if it fixes the problem if a chamber reaming isn’t possible.
OK, I’m goint to start by saying I have almost no rifle experience. That’s why I love this site: it teaches me a lot.
I have an M&P 15. I took it apart to check it over and familiarize myself more with the rifle. My extractor had the black insert and an O-ring. Is the o-ring the reason the extractor was hard to disassemle/reassemble? I’ve seen videos where it didn’t take much effort. It looks as though the o-ring acts as a type of bushing and stops the spring from compressing completely. Does the extraxtor just need to break in? I don’t plan on messing around with it anymore until I start training with it anyway.
Yes. Shitcan it. BCM doesn’t recommend using them. They do however include them with their bolts, because the booger eaters on ARF want them.
ahahaha…nice 
I LOL’ed at that even though I am a member at TOS as well…:eek:
I know this wont tell much but when you dump a round, it is using stick or ball powder?
I’ll get back to you on that.
Hmm… interesting info. I’ll have to take the o-ring out before my next range session and see if it works; not sure why it wouldn’t.