Proof Research Barrel Blank Features The Proof Research Barrel Blank brings PXT Proof Exponential Twist rifling technology to a carbon fiber bolt action barrel chambered in .308 Win. By dramatically reducing rifling lead angle and smoothing projectile engagement into the bore PXT reduces engraving force and minimizes throat erosion compared to conventional rifling resulting in less felt torque during firing for improved recoil control. In controlled testing PXT barrels have demonstrated 30 to 100 percent increases in barrel life while maintaining the accuracy standards expected from a Proof Research barrel. This Sendero contour blank is built with a 1:10 twist rate suited to common .308 Win bullet weights used in hunting and long range applications. Built around Proof Research s proven carbon fiber construction this 20 inch blank provides an exceptional stiffness to weight ratio that reduces overall rifle weight without sacrificing accuracy or durability. Designed for custom rifle builders and gunsmiths the blank offers a premium foundation for lightweight hunting rifles precision long range systems and modern high performance rifle builds. The 2.5 inch breech and 1.20 inch shank diameter give gunsmiths the dimensions needed to properly fit the blank to a given action. For builders seeking a lightweight high performance .308 Win barrel blank the Proof Research Barrel Blank is available for sale at GrabAGun. Proof Research Barrel Blank Specifications Manufacturer: Proof Research Model: Barrel Blank Caliber: .308 Win Action: Bolt Barrel Material: Carbon Fiber Barrel Finish: Stainless Twist Rate: 1:10 Type: Blank Grooves: 5 Barrel Description: Sendero Barrel Length: 20 Weight: 2 lbs. 13 oz. Available At: GrabAGun