The storied German concern of Walther - primarily recognized for their excellent work in pistols - took to the design of a machine pistol/submachine gun in the early 1960s. This was at a time when the German nation was still divided into an East and West, the lines drawn up after the fighting of World War 2 (1939-1945) has subsided. The weapon in question became the Walther MP ("Maschinenpistole") and involved two distinct variations of the base idea - the short-barreled MPK ("K" = "Kurz" for short) and the longer-barreled MPL ("L" = "Lang" for long). Both versions relied on the proven blowback system of operation common to submachine gun designs as well as the ubiquitous 9x19mm Parabellum pistol cartridge. Feeding was from a 32-round straight detachable box magazine.
Construction of the MP incorporated steel pressings for a robust overall casing. Design was highly conventional with an integral pistol grip at rear, the magazine feed just ahead of the grip and a short handguard shrouding the barrel within. Sights were affixed across the top front and rear of the weapon in the usual way through a combination aperture/open arrangement. The shoulder stock was a single-piece wire frame hinged at the rear of the receiver and at the base of the grip to fold over the weapon for a more compact footprint. The selective fire control was fitted to the left side of the gun body. The MPK and MPL variants were more or less identical, the difference being the use of a longer barrel in the latter as well as a lengthened handguard.
The MPK featured a weight of 6lbs (the MPL slightly heavier) while the weapon measured a length of 26 inches (14.7 inches with the wire stock folded. Comparatively, the MPL was given a length of 29 inches with a folded length of 18 inches. Barrel lengths were 6.8 inches for the MPK and 10.2 inches for the MPL. Rate-of-fire was identical in both designs at 550 rounds-per-minute. Effective firing ranges differed some - the MPK up to 100 meters and the MPL up to 200 meters.
The Walther MP product did not end up seeing the market success of its competitors such as the Israeli UZI and Heckler & Koch MP5 lines. It was ordered by Brazil, Colombia, Mexico (Navy), Portugal (Navy), South Africa (police), the United States (special forces), Venezuela and Zimbabwe. West German naval forces and police units both utilized the type.
Production of MP guns spanned into 1987.