F Diamondback Firearms OEM Replacement AR Barrel, 4.50in, 9mm Luger, 1-9.84in Twist, Black Nitride, 4150 Chrome Moly Vanadium Steel, 9X1945M50B984NFR $53.99 9X1945M50B984NFR show more like this Free Shipping on most orders over $49 Optics Planet