Proof Research Bolt Action Barrel Features The Proof Research bolt-action barrel starts as double stress-relieved 416R stainless steel a pre-hardened chromium alloy chosen specifically for its excellent machinability and consistent response to heat treatment across the full length of the bar. That uniform hardness allows the rifling to be cut to precise groove dimensions which is essential for repeatable bore-level accuracy in a competition barrel. The barrel is drilled contoured and reamed to the exact bore diameter of the .243 Win cartridge before rifling then hand lapped and individually inspected with a bore scope to confirm consistency from chamber to muzzle. This level of process control is what separates a match-grade barrel from a standard factory offering. Proof Research built its in-house steel barrel program on 15 years of Lawrence Barrels manufacturing experience giving this competition contour barrel a pedigree in precision rifle work. The 1.25 shank diameter and competition contour add stiffness that resists barrel whip under sustained strings of fire helping maintain point of impact through a match. At 7 pounds 14 ounces the barrel adds meaningful heft for stability without becoming unmanageable on a bolt-action platform. Arriving ready for a gunsmith to thread and chamber this Proof Research barrel gives serious competitors a proven foundation to build their next .243 Win rifle around. Proof Research Competition Barrel Specifications Manufacturer: Proof Research Caliber: .243 Win Barrel Length: 28 Twist Rate: 1:7.5 Contour: Competition Shank Diameter: 1.25 Material: 416R Stainless Steel Color: Stainless Weight: 7 lbs 14 oz Available At: GrabAGun