H&K’s MR556A1 takes much of its design from the Hk416, and is a perfect platform for both tactical and competition applications. The MR556A1 utilizes the H&K exclusive gas piston operating system, which employs a piston as well as a solid operating “pusher” rod instead of the gas tube used by most AR-type rifles. This “closed” operating piston system prevents excess gasses and hot carbon fouling from entering the receiver, which drastically reduces the risk of malfunctions that direct-impingement ARs are prone too. The closed piston system also helps prevent dust, sand, mud and other debris from entering for superior reliability in adverse conditions. In addition, the MR556A1’s barrel is made using H&K’s famous cold-hammer forging process and is constructed with highest quality cannon grade steel.
- Cold-hammer forged barrel
- “Closed” gas piston system
- Full length flattop picatinny rail
- M-LOK handgaurd