Originally Posted by rojocorsa
The Bravo Co BCG is a quality piece, which is why people like them. The bolt already comes with the o-ring for the extractor (and an extra one in the packaging). It's also magnafluxed and high pressure tested. Key is staked properly.
Plug and play and don't worry. Also, when I got mine, it was clearly test fired to ensure it worked, as there were brass marks on the bolt face.
Same can be said for any other well known "mil-spec" BCG like those from DD, LMT, Colt, PSA, etc.