AR9 Carbine Barrel 16" M4 Profile 9mm 1:10 Twist
AR9 Carbine Barrel 16" M4 Profile 9mm 1:10 Twist, This 16" M4 contour profile barrel is made of 4150 chrome moly vanadium steel with a parkerized finish and a 1:10 twist rate. The barrel is chambered in 9mm. 16" M4 Contour Barrel 4150 Chrome Moly Vanadium Steel Parkerized Finish 1:10 Twist 9mm Caliber 1/2x36 thread