Bushmaster Modular Carbine Upper Receiver/Barrel Assrmbly Preban

Features a 16 inch chrome lined chrome Moly steel fluted barrel with milled gas block. Four rail free-floater tubular forend combines with the A3 type flat-top upper receiver to provide all the Picatinny rails necessary for mounting sights, scopes or accessories. Molded rubber sure grip rail cover snap over the rail sections to add comfort and protection against heat buildup. The B.M.A.S. Rear Flip-up Sight is a dual aperture detachable unit with windage knob calibrated to 1/2 Minute of adjustment. B.M.A.S. Front Flip-up Sight clamps around the milled front gas block and incorporates an elevation adjustable front sight post - all ready for your lower receiver.