Rosco Manufacturing K9 Sage Dynamics Rifle Barrel 5.56 1-7 Twist 12.5in 1/2 x 28 Thread Black Nitire. 5 offers a proprietary patrol length gas system that is smoother than carbine length more reliable than mid-length. Features an optimized gas port to run reliably suppressed and/or unsuppressed. The K9 continuous taper is the most effective profile to dissipate heat from hard use. With weight shifted to the back of the barrel modern attachments on the front of the rifle create a perfectly balanced and better handling rifle. Updated target crown carried over from the Purebred series. Features no 90 degree cuts improved harmonics fit and finish. NOTE: COMES WITH PATROL LENGTH GAS TUBE Specifications for Rosco Manufacturing K9 Sage Dynamics Rifle Barrel: Manufacturer: Rosco Manufacturing Finish: Nitride Barrel Length: 12.5 in Barrel Profile: Contour Gas System Length: Patrol Gas Block Journal Size-Diameter: .750 in Threads per Inch: 1/2x28 Barrel Twist Rate: 1-7 Barrel Material: 416R Stainless Steel Weight: 27 oz Gas Block Journal Size-Length: 0.750 in Country of Origin: USA Features of Rosco Manufacturing K9 Sage Dynamics Rifle Barrel Non-Adjustable Gas Block Our Rosco Non-Adjustable Gas Blocks are purposely designed to be lined up perfectly with our barrels and gas ports to ensure reliable cycling every time. We have created two options for the end user; Our Non-Adjustable gas block is a direct plug in for any one of our barrels and has provisions for pinning our Adjustable block picks up where our standard block leaves off and works perfectly for shooters that want to be able to control their gas flow for suppressed applications. Adjustable Gas Block Our Rosco Adjustable Gas Block is purposely designed to be lined up perfectly with our barrels and gas ports to ensure reliable cycling every time. We have created two options for the end user; Our Non-Adjustable block is a direct plug in for any one of our barrels and has provisions for pinning our Adjustable gas block picks up where our standard block leaves off and works perfectly for shooters that want to be able to control their gas flow for suppressed applications. Package Contents: Rosco Manufacturing K9 Sage Dynamics Rifle Barrel Patrol Length Gas Tube Rosco Manufacturing K9-125-HY-SAGE-556-7-PT: K9 Sage Dynamics Rifle Barrel 5.56 1-7 Twist 12.5in 1/2 x 28 Thread Black Nitire