have a complete 10.3” 300blk upper that has a pistol adjustable gas block under the handguards. The gas block is an aero and the front sight was done by retro arms. This will come with one 20rd mag a brownells BCG and the troy rail and knights grip. The back story on this is I wanted a 300blk MK18 upper and no one makes a 300blk barrel with a FSB on it except for Noveske. They can get away with the carbine length because it’s 16”. If I were cut it down to 10.3” they don’t cycle, ask me how I know. Anyways I looked at every 300blk barrel I could find trying to find one that wasn’t turned down after the gas block preventing a FSB from being pinned. I would have preferred another brand but PSA was the only one I could find. This is slightly rare because I can’t find another single example of something like this anywhere. Trades I’m looking for old school 9mm smg flat top upper. Retro 9mm upper LMT enhanced carrier Aimpoint Duty RMR Criterion core 20” barrel. Glock 40 in 10mm