Proof Research Carbon Fiber PXT Barrel Blank Features The Proof Research Carbon Fiber PXT Barrel Blank is built around Proof s PXT rifling a complete rethinking of conventional twist progression engineered to reduce engraving force and smooth projectile engagement into the bore. By flattening the rifling lead angle PXT reduces throat erosion and felt torque during firing which in controlled testing has shown a 30 to 100 percent increase in barrel life while holding the accuracy standards Proof barrels are known for. The 1:9 twist rate suits a wide range of .308 Win bullet weights giving builders flexibility in load development. A stainless steel core wrapped in carbon fiber keeps the barrel stiff under heat while trimming weight off the finished rifle. The Sendero contour on this 24 blank balances rigidity with a manageable barrel weight for a build intended to be carried as well as shot. A 2.5 breech and 1.20 shank diameter give gunsmiths known dimensions to machine an action and chamber to making this a clean foundation rather than a finished product. At roughly 2 lbs 13 oz the blank keeps a custom rifle lighter than a comparable steel barrel without giving up the stiffness-to-weight ratio Proof is built on. Custom rifle builders and gunsmiths working on lightweight hunting rifles or precision long-range systems will find this blank a premium starting point for a .308 Win build. Proof Research Carbon Fiber PXT Barrel Blank Specifications Manufacturer: Proof Research Model: Carbon Fiber PXT Barrel Blank Type: Accessory-Barrels Caliber: .308 Win Barrel Length: 24 Twist Rate: 1-in-9 Contour: Sendero Breech: 2.5 Shank Diameter: 1.20 Finish: Carbon Fiber Material: Carbon Fiber Wrapped Stainless Steel Weight: 2 lbs. 13 oz. Available At: GrabAGun