Barrel: 18" barrel chambered in 5.56 NATO, 1:7 twist, M4 barrel extension, and a Rifle-length gas system. Barrel is finished off with a 13" PRI Gen 3 FDE Tube, PRI Cross Bolt Gas block/Flip up sight, Otter Creek SPR Collar, and Otter Creek Muzzle Device. Upper: Forged 7075-T6 A3 AR upper is made to MIL-SPECS and FDE Cerakote for durability. The upper has PRI Gen III SPR Peq top rail. 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: Complete Sabre-15 lower with Classic FDE grip and FDE Stock. FDE finish. Marked multi-caliber. Comes Standard with Springco Buffer Spring, Rifle Buffer, Battle Arms Development Pivot/Takedown Pins, Sabre Claw Two Stage Trigger, and Anti-Walk Pins.