AR15 A2 Upper (7.62 x 39) M4 Assembly in Tucson, Arizona For Sale

AR15 / M16 A2 Upper half with 16" inch M4 contour barrel (.310 bore) and A2 Upper receiver. This 7.62x39 cal barrel is 16" long, threaded the standard 1/2 x 28 tpi, and has an A2 flash hider with the correct crush washer. The barrel has a forged A2 front sight base with bayonet lug, not the cheaper cast front sight base which can break. It sports M4 contour and length handguards with full heat shields, and a correctly sized gas port for reliable function in full or semi auto. The barrel is machined from chrome-moly, high vanadium steel and hardened to a U.S. government Mil-spec of Rc 26-32. The barrel, and all external steel parts, are manganese phosphate finished IAW 5.3.1.2 of Mil-STD-171, the U. S. government's recommended protective finish for steel. These barrels are of Mil-spec M4 contour (.750 under the front sight base) complete with the M203 groove in the front. This contour is the perfect balance between light weight, heat dissipation, and accuracy. The barrel is button rifled with 6 grooves, right hand, 1 / 10" twist. The barrel is mounted on a A2 upper receiver with built in carry handle made from certified xxxxT6.511 alloy forgings, hardcoat anodized IAW Mil Spec Axxxx, Type III, Class II, black per No. xxxx8, Table IX with nickel acetate seal, as per the Mil-spec. This upper has the newest Mil-spec A2 adjustable sights that feature finger adjustable elevation to 800 meters and more than 30 minutes of windage adjustment at ½ MOA per click. The upper features a forward assist and hinged ejection port cover. This upper receiver is complete less bolt/carrier assembly and charging handle. The upper is fully assembled. Can provide bolt assembly or specific extractor for 7.62 x 39.