Anderson 16” 300 Blackout Complete Upper With EXT Forearm, 16” HBAR 300 Blackout Barrel. 1-8 twist. Phosphate Finish, Pistol Gas Set Up, 5/8-24 threads, .125 gas port, Anderson EXT Hand Guard Carbine Length, Knight Stalker Flash Hider, M16 Carrier is chrome lined, made from 8620 steel, Bolt is made from 9310 steel and coated per mil spec. MPI Tested. The 223 Bolt and Bolt Carrier Assembly comes complete with Cam Pin, Firing Pin and Firing Pin Retainer and Standard Charging Handle.