Barrel: 4150V Chrome Moly Vanadium steel. Chambered in 5.56 NATO, with a 1:7 twist, M4 barrel extension, and a carbine length gas system. This M4 profile barrel is finished off with a standard handguard in Olive Drab Green, F-Marked gas sight base, and an A2 flash hider. Upper: Forged 7075-T6 A3 AR upper is machined to MIL-SPECS and hard coat anodized. These uppers are made for us right here in the USA by a mil-spec manufacturer.