MR

The HK MR556A1 is the civilian-legal counterpart to the legendary HK416 used by special operations forces around the world, bringing genuine military-grade engineering to the semi-automatic market. At its heart is a proprietary short-stroke gas piston operating system derived from the HK G36, which keeps combustion gases out of the receiver and dramatically reduces heat and fouling compared to conventional direct impingement designs. This translates to enhanced reliability across extreme conditions and a bolt carrier group that runs cleaner for longer between cleanings.

The 16.5-inch cold hammer-forged barrel is machined from cannon-grade steel using Heckler & Koch's renowned process, featuring a taper-bore configuration with a slightly smaller diameter at the muzzle that improves both accuracy and muzzle velocity. The MR556A1 ships with a six-position adjustable buttstock, a free-floating aluminum handguard with M-LOK attachment points, and HK's proprietary short-stroke gas piston system. It accepts standard STANAG/AR-15 pattern magazines and every component is built to the exacting tolerances that have made HK rifles the standard-setter for piston-driven 5.56 rifles.