Bravo's BCM M4 Upper Receiver Assembly is precision machined to correct Mil-Specs from 7075 T6 forgings extension, providing the user with superior strength when dropped or when mortaring malfunction clearance drills. It has Mil-Std 1913 Rail for mounting optics and accessories, Mil-Spec forward assist with heat treated tool steel pawl, press fit and pinned cap, and a hard coat anodized finish. NOTE: Requires charging handle, barrel, handguard, gas block, muzzle device, gas tube and BCG (Bolt Carrier Group) to complete.