The only problemo ive ever had with an ar was a couple of years ago...been messin with em since 92.
On a 6.8..the SOB wouldnt lock back on function check....new folks....alway always check this first...if it doesnt do it...stop right there and figure out whats wrong...so,this rifle wouldnt lock back..there's a post where I stated the bcg got stuck in the drywall after I launched it in a hissy fit...lol I had drilled out the gas port to proper size...knew the buffer and spring was right on but switched it all out...checked out the bcg...checked out the gas block/tube...still the same end results WTF? the last thing I checked was inside length of the ebay bought buffer tube....yep...out of spec...too short
So, word to the wise...dont buy parts off of ebay..there are too many fine upstanding places to purchase...rather than ebay...those damn corksoakers :) Wash