I shot my AR-15 again last night, getitng ready for a 3 gun match Saturday. Mainly I was just making sure it still worked, and showing a buddy of mine how it works and getting him comfortable/confident with it. Well, the first two or thre mags went well, then it started Failing To Extract. Did this for several rounds, then worked like a champ. Changed mags, did the same thing for several rounds, then worked fine.
I think it's caused by the magazines. I just put in new springs (super duper chromium springs and plain ol' GI springs from magazine specialties) and I think maybe they're still too stiff. The first three mags we used we only loaded with 10-20 rounds each, all the rest had 30 in them. I also noticed I really had to smack them in to get them to latch up.
Think this is the case? Or could it be something else? Anything I can do other than load up only 20 rounds per mag?
How is it failing to extract? Stovepipe? Rim ripped off? Strong mag springs don't usually cause FTEs; sometimes causes FTFeeds, though. Doing this with several mags dosen't sound like a mag issue. It sounds like a one or all of these factors: really dirty/gunked chamber, weak extractor spring, dull/out-of-spec extractor, bad ammo, loose gas block. I would make sure that the ammo is good, the bolt, extractor, spring, ejector is good and clean, and the chamber is clean. Ghost