LanTac USA LLC Raven, 300 Blackout, 11.5 Barrel, Fits AR-15, Anodized Finish, 1:8 Twist, 5/8X24 Threads, Pistol-Length Gas System, Black LA00239 Lantac barrels are manufactured to the highest level of accuracy during the machining process. Each barrel is chambered and head spaced to a master bolt face with barrel extension individually matched to each barrel too. The barrel blanks are precision gun drilled, double reamed, precision honed and then rifled with a progressive button system utilizing 6 groove rifling that has been proven to produce the highest level of shooting accuracy.