Proof Research Sendero Barrel Features The Proof Research Sendero barrel blank is built around PXT PROOF Exponential Twist a complete rethinking of conventional rifling geometry and twist progression. By dramatically reducing the rifling lead angle and smoothing how the projectile engages the bore PXT reduces engraving force and throat erosion compared to conventional rifling. This translates into less felt torque during firing which improves recoil control and helps a shooter stay on target through follow up shots. In controlled testing PROOF has measured a 30 to 100 percent increase in barrel life with PXT rifling while still meeting the accuracy standards the Sendero contour is built around. Built on PROOF s proven carbon fiber construction the Sendero blank delivers an exceptional stiffness-to-weight ratio that keeps overall rifle weight down without giving up barrel rigidity. At a 1:7.5 twist rate across 16.5 inches with a 2.5 inch breech and a 1.20 inch shank diameter this blank is sized for builders working the .264 Cal bore. The finished blank weighs just 2 lbs 8 oz a meaningful weight savings over a comparable steel barrel on a hunting or long-range rifle. Designed for custom rifle builders and gunsmiths the Proof Research Sendero offers a premium foundation for lightweight hunting rifles and precision long-range rifle builds for sale at GrabAGun. Proof Research Sendero Barrel Specifications Manufacturer: Proof Research Model: Sendero Caliber: .264 Caliber Action: Bolt Barrel Material: Carbon Fiber Twist Rate: 1:7.5 Type: Blank Grooves: 5 Barrel Length: 16.5 Barrel Breech: 2.5 Shank Diameter: 1.20 Weight: 2 lbs 8 oz Available At: GrabAGun