Barrel: Barrel is made for Palmetto State Armory by FN Manufacturing using their proprietary blend of hammer forged chrome molly vanadium that is referred to as "Machine Gun Steel" by virtue of its use in FN's M249 and M240 weapons. The hammer forging process work hardens the steel, making it more durable. In addition, the chrome process for the bore allows for a lining almost twice as thick as a standard M16 for enhanced durability. Chambered in 5.56 NATO, with a 1:7 twist, M4 barrel extension with extended feed ramps, and a carbine gas system. The barrel has an A2 style profile, is Mil-spec phosphate coated, and MPI/HPT tested. The upper is finished off with a .750" low profile gas block, PSA 9" Lightweight Hex Full Picatinny M-Lok Free Float Rail, and an A2 flash hider. Upper: Forged 7075-T6 A3 AR upper is made to MIL-SPECS and hard coat anodized black for durability. Featuring machined T marks, and a mil-spec finish. These uppers are made for us right here in the USA by a mil-spec manufacturer. **Does not include bolt carrier group or charging handle.