Barrel: PSA CHF Chrome Lined 10.3" barrel chambered in 300BLK with a 1/5 twist, M4 barrel extension, and a pistol-length gas system. Barrel is finished off with an F-marked front sight post at the carbine-length position, FDE anodized quad rail handguard, and a Sabre Plan B compatible flash hider in Black Nitride.Upper: Forged 7075-T6 A3 AR upper is made to MIL-SPECS and hard coat anodized FDE 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 HAR-15 Pistol Brace and Sabre grip. FDE anodized finish. Marked multi-caliber. Comes standard with Springco Buffer Spring, Battle Arms Development Pivot/Takedown Pins, Sabre 2-Stage DLC Trigger, and JP Reduced Power Springs.** When shooting suppressed with supersonic ammunition, an H2 buffer is recommended to ensure proper function and optimal reliability.