PROOF Research designed these long range specific barrels that feature their rifle length plus 2" (CAMGAS) gas system to moderate bolt carrier velocity and dwell time issues that previously plagued Creedmoor and 260 AR barrels. The proprietary gas tube is included, but requires use of a JP enhanced High Pressure bolt for best function. (452-000-113) PROOF Research's match-grade carbon fiber barrels are stronger, lighter, and as accurate as the finest precision steel barrels and will maintain their performance in the harshest conditions. Up to 64% lighter than traditional steel barrels Match-grade accuracy Improved heat dissipation for cooler and longer las Mfg: Proof Research