Due to a process called Single Point Cut Rifling, these replacement barrels have an exact twist and a more uniform bore and groove. These barrels are pre-lapped before rifling and finish-lapped after rifling. These barrels feature AI's proprietary target type contour. These barrels are compatible with Accuracy International's AT and AX weapon systems. Accuracy International AT/AX Black 6MM Creedmoor 26" 5/8"-24 w/cap 2018 Profile Barrel 0726082BL