Umarex Heckler & Koch Airsoft Rifle Mp5K Black, Multi. By eliminating the need for a stock and cutting down the receiver and bolt of the MP5K, the once submachine gun – now machine Airsoft pistol – is a near king. Being such a small system, coupled with its higher rate of fire, the MP5K Airsoft rifle was the optimal choice. The H&K MP5K is designed to be an accurate Airsoft provide an excellent airsoft gun for players looking for a compact AEG. The MP5K features a full metal body, for a more realistic weight. Heavy metal upper receiver and barrel assembly. Durable nylon polymer lower receiver, vertical grip, and optional folding stock. Configurable with sling backplate. Fixed Front and Adjustable Rear Sights. Umarex Heckler & Koch MP5K Airsoft Rifle Specifications. Max Velocity: 280 fps. Barrel Length: 4.25′. Weight: 5.0 lbs. If the wrong contact details are provided any losses incurred as a result will be the buyers responsibility.