The Heckler & Koch MP5SD4 is a germany-made select-fire submachine gun chambered in 9mm Luger, introduced in 1974. Primary use: military. Type: Submachine Gun Action: Select-Fire Caliber: 9mm Luger Capacity: 25 Year introduced: 1974, Germany Weight: 88 oz Overall length: 27" Status: Active Intended use: military