I have a Durkin Tactical 10.5” 300 black out upper cerekoted in FDE. Upper has the nitride BCG and have upgraded to a seekins adjustable gas block to tune for supers or subs. Has milspec charging handle. Upper has only 260 ish rounds though it. Decided to go for a longer build. Asking $300 cash NO TRADES PLEASE. Text me as I will not respond to the emails 210-7four0-111one