Proof Research M24 Barrel Features The Proof Research M24 Contour Barrel is chambered for .264 caliber and cut to 28 inches with a 1 in 8 twist rate giving it the stability needed to shoot heavier for caliber long range bullets accurately. Proof Research builds these barrels from double stress relieved 416R stainless steel a pre hardened chromium alloy specifically engineered by barrel makers and rifle manufacturers for match grade consistency. The material s homogeneous microstructure responds evenly to heat treatment providing uniform hardness along the full length of the barrel that is necessary for precise rifling to exact groove dimensions. Each barrel is drilled contoured reamed rifled hand lapped and individually inspected with a bore scope before it ships. The M24 contour carries a 1.20 inch shank diameter and weighs roughly 6 pounds 10 ounces matching the profile originally developed for the military s M24 sniper weapon system. Because Proof Research arrives at 416R stainless in long lengths before cutting each barrel to finished length the material s excellent machinability and exceptional polishability translate directly into a uniformly lapped accurate bore. This barrel arrives ready for threading and chambering by a gunsmith rather than as a drop in finished part. Precision rifle builders looking to replicate a proven long range platform will find this M24 profile a dependable foundation for their .264 caliber build. Proof Research M24 Barrel Specifications Manufacturer: Proof Research Caliber: .264 Cal Barrel Length: 28 Twist Rate: 1-8 Contour: M24 Shank Diameter: 1.20 Material: 416R Stainless Steel Color: Stainless Weight: 6 lbs 10 oz Available At: GrabAGun