Product Description The Rosco Manufacturing Bloodline 11.5" M4 5.56 NATO Barrel is purpose-built for shooters who demand precision engineering in a compact package. Crafted from premium 4150 Chrome Moly Vanadium (CMV) steel and finished with a durable Nitride treatment, this barrel is designed to be the ideal foundation for any Short-Barreled Rifle (SBR) or pistol build. Rosco&';s Bloodline series reflects a commitment to modern carbine performance, incorporating properly managed dwell times, optimized gas port diameters, and carefully selected twist rates to deliver reliable function whether running suppressed, in a patrol carbine, or in a competition setup. With input from both civilian consumers and military end users, Rosco has engineered a barrel that meets real-world demands rather than relying on outdated specifications. Product Highlights Premium 4150 CMV Steel Construction: Built from high-strength Chrome Moly Vanadium steel for exceptional durability and long service life in demanding conditions. Nitride Finish Inside and Out: Both the barrel and barrel extension receive a Nitride finish, providing outstanding corrosion resistance and improved wear characteristics. Optimized Carbine Gas System: A carbine-length gas system with a .750" gas block journal ensures reliable cycling across a wide variety of ammunition and suppressor configurations. 1/2x28 Threaded Muzzle: Standard 1/2x28 threading allows compatibility with a wide range of muzzle devices, including flash hiders, compensators, and suppressors. 1:7 Twist Rate for Modern Ammunition: The 1-in-7" twist rate is optimized for stabilizing heavier .223/5.56 NATO projectiles preferred by modern carbine shooters and military end users. Specs Brand: Rosco Manufacturing Model: Bloodline Manufacturer Part Number (MPN): BL-115-M4-556-7-C UPC: 181969500029 Barrel Length: 11.5" Barrel Weight: 20.82 oz Barrel Material: 4150 CMV Barrel Caliber: 5.56 NATO (.223 REM) Barrel Profile: M4 Twist Rate: 1:7" Barrel Thread: 1/2 x 28 Gas Block Size: .750" Gas System Length: Carbine Barrel Crown: 11 Degree Barrel Finish: Nitride Barrel Extension Finish: Nitride 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. ]]>