Like its 5.56mm counterpart, the MR762A1 is a direct descendent of the HK416/417 series, only in a semi-automatic rifle configuration developed for civilian users. Using the HK-proprietary operating system, the MR762A1 is gas-operated and uses a piston and a solid operating pusher rod in place of the common gas tube normally employed in AR15/M16/M4-style weapons. This system ensures that the MR762A1 stays cleaner, reducing heat transfer to the bolt and bolt carrier, and drastically reducing wear and tear on other critical components. The MR762A1 uses a barrel produced by Heckler & Koch's famous cold hammer forging process. This manufacturing process uses the highest quality steel, producing a barrel that ensures superior accuracy, even after firing thousands of rounds. The MR762A1 also uses many of the assemblies and accessories originally developed for the HK416/417 series including adjustable buttstocks, ergonomic pistol grips, mechanical sights, and the HK free-floating four-quadrant Picatinny rail system that allows all current M4/M16-type accessories to be attached. Ambidextrous operating controls are standard on the MR762A1, including a convertible charging handle and an ambidextrous selector lever. 16.5" barrel with a 1 in 12" twist. 10-round magazine. No sights included.