Hitler’s Germany was the leading country in the development of the assault rifle. Even the term "assault rifle", is no more than a translation of the German term Sturmgewehr, devised for propaganda reasons by no less than Hitler himself (or at least so the legend goes).
Germany began to develop intermediate cartridges during the mid-1930s. There were some developments in 7 mm and 7.75mm caliber, but Heereswaffenamt (HWaA, or department of armaments), decided to retain the existing rifle caliber of 7.92mm, to save money on new machinery that would otherwise be required to produce bullets and barrels of a non-standard caliber. The new 7.92mm "short infantry cartridge" (Infanterie patrone Kurz),developed by the Polte Werke in 1938, was officially designated the 7.92mm PP Kurz. It had metric dimensions of 7.92x33mm, considerably shorter and less powerful than the standard 7.92x57mm rifle / MG cartridge, and propelled a 8.1 g (125 grain) bullet to roughly 680 meters per second.
In 1939 HWaA issued a contract for the development of a "Maschinenkarabiner", or machine carbine (MKb for short), chambered for the new Kurz cartridge, to the company C. G. Haenel Waffen und Fahrradfabrik. Initial development took place under the designation of MKb.42 - Maschinenkarabiner, 1942. The new weapon was intended as a replacement for submachine guns, bolt action rifles and, partly, light machineguns for front troops and was intended to have an effective range of 600 meters or so.
The famous designer Hugo Schmeisser led the Haenel development team, which produced the first working prototypes of new weapon by 1942, known as MKb.42(H). After extensive combat tests of the MKb.42(H), HWaA asked Haenel for several significant improvements over their initial design. Most notable was the request to replace the submachine-gun like open-bolt firing system with more convnient closed-bolt system, to improve single-shot accuracy. Schmeisser zdesigned the weapon accordingly, and by 1943 submitted the improved version to the HWaA. But by this time Hitler had ordered that only existing types should be developed and manufactured, and the Maschinenkarabiner was not on this list. To avoid this nuisance, the Germans decided simply to rename the MKb to the MP, or Machinen pistole (submachine gun), which was on the “approved” list. So, the new and improved weapon received the designation MP-43, and went into limited production and field trials at the front. During the following year,the MP-43 experienced several minor modifications, leading to MP-43/1and MP-43/2 designations, but these differed only in details such as front sight bases and grenade launcher interfaces.
In April 1944 the designation of all MP-43s was changed to MP-44, with no actual changes made to the design. At this time there were plenty of glowing reports from the German troops fighting with MP-43s and MP-44sat the Eastern front. Seeing these reports, Hitler finally approved the mass production and issue of the new “wunderwaffe”, and in December 1944 officially christened it the Sturmgewehr, or Assault Rifle, 1944 (StG.44) This was a pure act of propaganda, but the name stuck not only to that gun, but also to the whole new class of automatic weapons designed to fire intermediate cartridges.
The total number of MP-43s, MP-44s and StG.44s produced was about 450,000, and these guns proved very effective, but not without some flaws. After the end of the war the direct development of the Stg.44 was stopped, but the East German police used some remaining guns. Another major post-war user of Stg.44 was Yugoslavia; their paratroopers used it under the designation "Automat, padobranski, 7.9 mm M44, nemacki" until the early 1980s, when the Kalashnikov-type M64 and M70 rifles finally replaced it. Yugoslavia also produced 7.92x33mm Kurz ammunition until the late 1970s.
The StG.44 (like its earlier versions MP.43 and MP.44) is a gas operated, selective fire weapon. The receiver and trigger housing with pistol grip are made from steel stampings, with machined steel inserts. The trigger housing with pistol grip is hinged to the receiver and folds down for disassembly. The gas drive utilizes a long-stroke piston, and the bolt is tipped down to lock into the receiver. The gun is fired from a closed bolt. The MP-43and subsequent versions all were hammer-fired, while the MKb.42(H) was striker-fired. The safety lever is located at the left side of the pistol grip unit, and a separate cross-bolt type of fire mode selector allows for single-shot and full auto fire. The charging handle is attached to the gas piston rod, and the ejection port has a dust cover. The recoil spring is located inside the wooden butt. At the top of the butt there is container for a cleaning kit, closed by the spring-loaded steel cover. The Stg.44 was provided with open, leaf-type sights, and could be fitted with telescope sights or a specially developed active infrared sighting unit, called “Vampir” (vampire).
The muzzle of the Stg.44 was threaded to accept a cup-like grenade launcher; a special muzzle nut usually covered the threads. The Stg.44 also could be fitted with a special curved barrel attachment (“Krummlauf”), which allowed the gun to be fired “around the corner” or from inside a tank, without exposing the shooter to the enemy fire. Several types of these attachments were developed, but only one type, the 30-degree “Krummlauf Vorsatz J”, was apparently manufactured in any significant numbers. This device had a special mirror sighting adapter and reduced the bullet velocity down to mere 300 meters per second due to the high friction in the curved barrel extension. This apparently did not bother the German Army, since these curved barrel adapters were intended for short-range encounters only.