F Moriarti AR-15 M4 Barrel Threaded, 5.56x45mm NATO, 16 inch, M4, 1-7 Twist, 1/2x28 Thread, Nitride, Black, 16 inch, MAR-16-M4-556 $119.99 MAR16M4556 - Free Shipping on most orders over $49 Optics Planet