Want one of the best SBR or Pistol setups in the market today? You found it! These uppers utilize the M4A1 style barrel with M203 flats. Chambered in 5.56 NATO, 1/7 twist, chrome lined chamber and bore. F-Marked front sight base is pinned with taper pins after phosphate finishing no bare metal under your FSB here. Upper receiver is 7075-T6 forged with type 3 black hard coat with M4 feed ramps. Double wall M4 type handguards and A2 flash hider finish this upper off.