The PROOF Research AR 308 PR-10 barrel provides owners of AR-10-pattern rifles with a 6.5 Creedmoor-chambered rifle that includes a number of enhanced features over traditional barrel styles. These long range specific barrels provide the ultimate in accuracy and will maintain their performance in the harshest of conditions. The PROOF Research AR 308 PR-10 barrel uses the company's innovative CamGas system, which works to reduce the speed of the bolt carrier and improve overall function and reliability of 6.5 Creedmoor semi-auto rifles. Provide shooters with enhanced accuracy on par with match-grade guns Better cooling properties provide improved barrel life Mfg: Proof Research