Hey all. I have a nitride coated BCG and even sqeaky clean barely reciprocates the bolt within the bcg (extremely tight tolerances). A normal bcg feels like it rattles in comparison so when even a tiny bit of power builds up on the back of the bolt it has no room to turn . Has Anyone ever Had this strange problem? What would be the solution it won't just break in its been hundreds of rounds Is there a way to sand the parts down or another way to make the parts break In quicker ? I've never had such a strange issue.  With a standard BCG this same barrel would run for hundreds of rounds between cleaning never an issue .it is a short Dead Foot Arms setup so just buying a new BCG isn't an option quite yet . Thanks guys I really appreciate it I carry it for defense while in the wild so it has to work . It is absolutely match grade and way under sub Moa but I need it to run not shoot tiny groups .

who made that and where did you get it
what upper and barrel?

Hey thanks.  It is a dead foot arms bcg it Is one inch shorter then standard.  It's flawless otherwise I love this company but Recently they sent me a new bolt that is extremely tight in the carrier the old one was also .I know is nitrided my first experience with that and yea it barely rotates in the bolt carrier . I have some fouling issues I've posted about elsewhere but nothing so severe it should be not going into battery after 60 rounds.  There Is simply no room at all for the bolt . I've had this barrel don't know the make over 10k rounds in it never an issue . The upper is a midway slim upper no forward assist and yeah funny you mention because there Is a large chunk of metal or just paint broken off or chipped where the cam pin rotates . So In summary I'm thinking the tolerances are just way too tight..is there any safe way to reduce those I hate to get a new bolt and mess with the bolt and barrel seating well together now . Thanks again!

Also I think it's easy to blame the AR system in general for it barfing  in its mouth but if you had a bolt this tight in an AK or any other gun I think it would at least in theory alter reliability too. Before this bcg I had close to 10k trouble free rounds using a stanard bcg .it is a 300 aac 7 5 inch barrel pistol tube and for anyone not familiar it Is a 2.5 inch buffer tube setup very clever system . Before this I used a kentri 3.5 buffer tube setup and that used a standard bcg and it would run like an AK boring reliability

Since nitride isn't really a coating but a hardening treatment, the bolt would have had to have started off out of spec. Are you sure it's the bolt itself and not the rings? I'd pop the rings off and check again. Rings are cheap to replace. Without gauging the carrier and bolt it's impossible to say what ain't right but that's where I would start.

why not pop a different bolt (with its rings) in the carrier and see what happens?

eta: did I read "... chunk missing from a part..." ?  that sounds like time to replace that part. I have uppers and bcg in shopping carts from reputable manufacturers that I don't need because they are such good deals right now.  I keep deciding not to buy today...  one day I might regret that (thinking of WA state right now...)