This HK416 M4 style barrel fits any HK416 or MR556 rifle. Inspired by the military issue HK416 carbines and their corresponding barrel, this M4 profile barrel fits HK416 upper receivers and MR556 rifles. The barrels start with an authentic, original HK416 barrel extension. Two inserts are included, which will work with any style of HK416 upper receiver. Some HK416 and MR556 uppers require a different sized index tab or pin, these barrels accommodate all! Barrels are produced in the US and feature a matte black Isonite finish. Barrel twist is 1-7, and are chambered 5.56x45mm NATO. Muzzle is &f Mfg: Brownells
