CMMG Barrel Sub-Assembly - 10.5", 5.56x45mm Barrels are the heart of any rifle or pistol build, and CMMG delivers with precision-engineered components crafted to exacting quality standards. The CMMG 10.5" 5.56x45mm Barrel Sub-Assembly is built from 4140 chrome moly steel with a Salt Bath Nitride (SBN) finish, offering outstanding corrosion resistance and durability in a compact, carbine-length package. Each barrel sub-assembly is properly headspaced at the factory, ensuring it is ready to drop into your next AR pistol or SBR build without guesswork. The 1:7 twist rate handles a wide range of 5.56 NATO and .223 Remington projectiles, while the 1/2-28 muzzle threading accommodates most standard AR-platform muzzle devices. Product Highlights Precision 4140 Chrome Moly Steel Construction: Machined from high-quality 4140CM steel for long-lasting strength and reliable performance under sustained fire. Salt Bath Nitride (SBN) Finish: Provides superior corrosion and wear resistance compared to traditional phosphate finishes, extending barrel service life. Factory Headspaced: Every barrel sub-assembly is headspaced at the CMMG facility, guaranteeing proper fit and reliable function right out of the box. 1:7 Twist Rate: Optimized for stabilizing a broad spectrum of 5.56x45mm projectiles, from lighter 55-grain loads to heavier 77-grain rounds. 1/2-28 Muzzle Threading: Compatible with a wide range of standard AR-platform muzzle devices, including flash hiders, compensators, and suppressors. Specs Brand: CMMG MPN: CMM55D8D0A UPC: 810046235577 Caliber: 5.56x45mm (5.56 NATO) Barrel Length: 10.5" Barrel Twist: 1:7 Barrel Contour: MT (Medium Taper) Barrel Material: 4140 Chrome Moly (4140CM) Finish: Salt Bath Nitride (SBN) Muzzle Thread: 1/2-28 Gas Port Location: Carbine Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.