Proof Research PXT carbon fiber barrel blanks give custom rifle builders and gunsmiths a premium starting point for a lightweight, high-performance rifle. This .257 caliber blank measures 20.00" in a Sendero contour with a 1:7.5 twist, a 2.5" breech and a 1.20" shank, and the carbon fiber construction delivers a high stiffness-to-weight ratio that trims overall rifle weight without giving up accuracy.

PXT is Proof's Exponential Twist rifling, a rework of conventional rifling geometry and twist progression that lowers engraving force, reduces throat erosion and eases the bullet's entry into the rifling. The reduced rifling lead angle also cuts wear and felt torque during firing, and Proof reports a 30-100% increase in barrel life for PXT barrels in controlled testing while holding its accuracy standards. The .257 bore suits quarter-bore chamberings such as .257 Roberts, .25-06 and 25 Creedmoor, leaving the chambering and finish work to the builder.

• Brand: Proof Research
• Model: PXT Barrel Blank
• Caliber: .257
• Barrel Length: 20.00"
• Rifling: PXT (PROOF Exponential Twist), 1:7.5 Twist
• Construction: Carbon Fiber, Sendero Contour
• Part Number: 157503