Proof Research Blank Features The Proof Research Blank is built around Proof s carbon fiber wrapped barrel technology which combines a precision machined steel core with a carbon fiber outer sleeve to significantly reduce weight compared to a traditional steel barrel. Chambered in .264 Win Mag this barrel blank carries a 1:7.5 twist rate a stabilizing rate suited to the longer heavier bullets often used in long range .264 applications. The Sendero Light profile balances rigidity with reduced weight making it well suited to mountain rifles and other weight conscious builds. At 20 inches long the barrel offers enough length to achieve strong velocities from the .264 Win Mag cartridge. With a 2.5 inch barrel breech and a 1.20 inch shank diameter this blank is designed for gunsmiths to fit to a bolt action receiver during a custom build. Weighing just 2 pounds 10 ounces the carbon fiber construction offers a meaningful weight reduction over a comparable steel barrel of the same length and profile. A 5 groove rifling pattern completes the barrel s construction contributing to consistent bullet engagement and accuracy. For builders working on a custom long range .264 Win Mag rifle the Proof Research Blank offers a proven combination of light weight and precision. Proof Research Blank Specifications Manufacturer: Proof Research Series: Blank Caliber: .264 Win Mag Barrel Length: 20 Action: Bolt Barrel Material: Carbon Fiber Barrel Type: Blank Barrel Description: Sendero Light Profile Color: Carbon Fiber Twist Rate: 1:7.5 Diameter: .856 Grooves: 5 Shank Diameter: 1.2 Weight: 2 lbs 10 oz Available At: GrabAGun