F Diamondback Firearms OEM Replacement Barrel, FN Herstal, M16, 5.56x45mm NATO, 16in, Medium Profile, Mid-Length, 1-8 Twist, 1/2 x 28 Thread, 4150 CrMov, Black Nitride, 556M16M50B8R $89.99 556M16M50B8R show more like this Free Shipping on most orders over $49 Optics Planet