Barrel: 10.5" 4150V Nitride. Chambered in 5.56 NATO, 1:7 twist, M4 barrel extension, and a Carbine-length gas system. Barrel is finished off with a 12" PSA Suppressor Ready Quad Rail, and a OEM PSA Custom Fluted 5.56 Flash Can. Upper: Forged 7075-T6 A3 AR upper is made to MIL-SPECS and hard coat anodized black for durability. These uppers are T-Marked engraved. Bolt Carrier Group: Father's of Freedom BCG by Microbest with Sprinco Extractor Spring and Carpenter 158 MP Bolt.