Barrel: 20" 416R Stainless. Chambered in .223 Wylde, with a 1:8 twist, M4 barrel extension, and a mid-length gas system. Barrel is finished off with our Patent Pending 18" PSA Sabre Lock Up Handguard, adjustable gas block, 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.