Take advantage of the next generation evolution in .22 caliber ballistics with a 20 22 ARC. Designed for the AR15 platform 22 ARC is made to take advantage of the heaviest 22 caliber bullets for an exceptional shooting experience. - Caliber .22 ARC - Barrel Length 20 - Barrel Twist 1:7 - Barrel Contour MT - Barrel Material 4140CM Nitride Finish - Barrel Twist 1:7 - Muzzle Thread 1/2 x 28 - Gas Port Location Rifle