This M4 Barreled Upper Assembly is complete and ready for you to add your choice of Optics or Rear Sights. The highly accurate 16” M4 profile barrel is chrome lined and machined from 4150 Chrome Moly Vanadium steel - rifled 1 x 7 Right Hand twist. An A2 Flash Suppressor and standard A2 F-Marked Front Sight are fitted. The machined aluminum flat top Upper Receiver is complete with Bolt Carrier Assembly (if selected), Charging Handle (if selected), Forward Assist, and Ejection Port Cover. The 14.5" barreled upper will have a pinned and welded extended A2 upper.
The Knights Armament Rail Interface System (RIS) was designed at the request of the United States Special Operations Command (SOCOM) for the SOPMOD program. It allows the individual operator to free-float the M203 grenade launcher without additional parts.