Proof Research PXT 308 Win Carbon Fiber Sendero Light Barrel

Proof Research builds the PXT line around what the company calls Exponential Twist — a rework of conventional rifling geometry meant to cut engraving force on the bullet, slow throat erosion and smooth the transition as the bullet takes the rifling.

Dropping the rifling lead angle also reduces felt torque during the shot, which helps a shooter hold the reticle where it started. Proof reports a 30 to 100 percent gain in barrel life from PXT in controlled testing. This one is a carbon fiber 308 Win barrel in the Sendero Light pattern for a bolt gun.