Barrel: The Nitride treated 4150V chrome moly steel is chambered in 300AAC Blackout, with a 1:8 twist rate, M4 barrel extension, and pistol-length gas system. This heavy profile barrel is finished off with a PSA 10" Sabre QD Rail, and a Sabre compensator. 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. Lower: Palmetto State Armory complete Sabre-15 lower with SBA3 Brace and Sabre grip. Black finish. Marked multi-caliber. Comes Standard with Springco Buffer Spring, Battle Arms Development Pivot/Takedown Pins, Sabre 2-Stage DLC Trigger, JP Reduced Power Springs, and Anti-Walk Pins. Made in America and compatible with all AR-15 uppers.