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. This black .260 Rem barrel is 24" long, has a 5/8x24 thread, and fits Accuracy International AT/AX short action rifles. Accuracy International .260 Rem 5/8"x24 24" AT/AX Barrel 1224062BL