For sale is a FN M4 clone upper receiver. It is a complete upper assembly by FN, not pieced together. Has Knights (KAC) quad rail, KAC rail covers and KAC vertical foregrip. Barrel is an FN 1/7 twist 5.56 nato with a pin and welded A2 flash hider. Bolt carrier is FN M16 profile with 158 bolt, chrome lined carrier, and properly staked gas key screws. Will include a Troy Industries fixed rear sight to complete the upper. Upper has about 500 rounds through it and is in good condition. Asking $750 OBO for the upper. Can be reached at 832-703-27 two three