Product Description The Rosco Manufacturing K9 12.5" Sage Dynamics barrel is a precision-engineered AR-15 barrel built for hard use and tactical excellence. Chambered in 5.56 NATO and machined from premium 416R stainless steel with a durable nitride finish, this barrel features Rosco&';s proprietary patrol-length gas system that delivers smoother cycling than carbine-length and superior reliability compared to mid-length setups. An optimized gas port ensures dependable function whether running suppressed or unsuppressed. The K9 continuous taper profile is purpose-designed to efficiently dissipate heat under sustained fire, while the rearward weight distribution pairs perfectly with modern front-end accessories for a perfectly balanced, fast-handling rifle. The updated recessed target crown, carried over from the Purebred series, delivers improved harmonics along with outstanding fit and finish. This barrel ships complete with a patrol-length gas tube and is compatible with a minimum 10-inch handguard. Manufactured in the USA. Product Highlights Proprietary Patrol-Length Gas System: Smoother than carbine length and more reliable than mid-length for consistent, repeatable cycling in any conditions. Optimized Gas Port: Engineered to run reliably both suppressed and unsuppressed, making this barrel ideal for versatile tactical setups. K9 Continuous Taper Profile: The most effective barrel profile for heat dissipation during hard use, with weight shifted rearward for superior rifle balance. Recessed Target Crown: Updated design carried over from the Purebred series for improved harmonics, precision fit, and excellent finish quality. Includes Patrol-Length Gas Tube: Ships ready to install with a matching patrol-length gas tube; compatible with a minimum 10-inch handguard. Specs Brand: Rosco Manufacturing Caliber: 5.56 NATO Barrel Length: 12.5 inches Barrel Material: 416R Stainless Steel Barrel Profile: Continuous Taper (K9) Barrel Finish: Nitride Barrel Extension Finish: Nitride Twist Rate: 1:7 Muzzle Thread: 1/2x28 Gas System Length: Patrol Gas Block Journal Size: 0.750 inches Crown: Recessed Target Weight: 27.05 oz Compatibility: AR-15 (minimum 10-inch handguard recommended) Includes: Patrol-Length Gas Tube Country of Origin: USA UPC: 850039693069 MPN: K9-125-HY-SAGE-556-7 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. ]]>