The M5 .308 Assembled Upper Receiver comes with both the port door and forward assist hardware preinstalled. Forged from 7075-T6 aluminum, this assembled upper is precision machined to accept standard .308 components and is the ideal upper for your big bore build. It includes M4 Feedramps, .2795 takedown pin holes (DPMS size), and DPMS High Profile (.210) Tang). NOTE: Requires charging handle, barrel, handguard, gas block, muzzle device, gas tube and BCG (Bolt Carrier Group) to complete.