Product DescriptionThe Rosco Manufacturing K9 11.5 inch 5.56 NATO barrel is engineered for hard use with a proprietary patrol-length gas system designed to be smoother than carbine length and more reliable than mid-length. Its optimized gas port is tuned to run reliably suppressed and unsuppressed, while the K9 continuous taper profile helps dissipate heat during sustained firing. Weight is shifted rearward to improve balance when using modern front-end attachments, and an updated target crown (carried over from the Purebred series) enhances harmonics, fit, and finish.Product Highlights 11.5 inch 5.56 NATO barrel with K9 continuous taper profile for efficient heat dissipation Proprietary patrol-length gas system for smooth cycling and dependable reliability Optimized gas port for consistent performance suppressed or unsuppressed Nitride finish on stainless steel for durability and corrosion resistance Updated target crown for improved harmonics and refined fit and finishSpecs Brand: Rosco Manufacturing Model: K9 Caliber: 5.56 NATO Barrel Length: 11.50 in Material: Stainless Steel (416R) Finish: Nitride Twist Rate: 1:7 Muzzle Thread: 1/2 x 28 Gas System Length: Patrol-length Weight: 25.47 oz MPN: K9-115-HY-DUFFY-556-7 UPC: 850039693083Disclaimer: 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.