Ballistic Advantage Premium Black Series, Hanson Mid-Length Barrel, 243 Winchester, Fits AR-10, 18 Barrel, 5/8x24 Thread Pitch, 1:10 Barrel Twist, Mid Length Gas System,Bead Blasted Finish, Black, Includes Low Profile Gas Blocked Pitch BABL243001PQ This 243 Win 18" barrel is machined from 416R Stainless Steel with a QPQ finish. Ballistic Advantage's Premium Black Series Barrels are proof-fired and MPI-tested" ensuring the best quality and accuracy.