Hello all, up for sale is a Colt 6551 AR that is in great shape. I wanted to replicate as near as possible an M16a2 so I solt the orig. upper and purchased an 100% Colt USGI 20" upper for it. 1/7 twist marked mpc, f/h AND bayo lug, upper marked "C", colt bolt/carrier and chrome lined barrel. This gun has been used but never abused and has less than 2000 rds down the pipe. $925 The rifle is a pre-ban for those who care. $925 FTF in Indy or + shipping. Plenty of references. I also have NEW KAC M5 rail system w/ covers and fwd grip. for addt'l $225 for the buyer.