Sub-MOA Accuracy Guarantee w/ Black Hills Match Grade Ammunition Billet Machined 7075-T6 Upper Receiver w/ M4 Feed Ramps Proprietary Extended Aluminum Hand Guard w/ Magpul M-LOK Modular Mounting System and Integrated Upper/Hand Guard Stainless Steel Anti-Rotation Pin Match Grade 416R Stainless Steel Barrel w/ Polished Crown and Feed Ramps, Chambered in .223 Wylde/5.56 NATO or 300 BLK, Threaded 1/2 x 28 (.223) or 5/8 x 24 (300 BLK) Enhanced Black Nitride M16 Bolt Carrier Group Lightweight Forward Assist Radian Raptor-SD Suppressor-Optimized Ambidextrous Charging Handle Direct Impingement Gas System