was difficult and expensive to manufacture. Shortly thereafter, the simpler Sten submachine gun was developed for general use by the British armed forces, it was much cheaper and faster to make. Over 4 million Sten guns were made during World War II. The Sten was so cheap and easy to produce that towards the end of the war as their economic base approached crisis, Germany started manufacturing their own copy, the MP 3008. After the war, the British replaced the Sten with the Sterling submachine gun. The United States and its allies used the Thompson submachine gun, especially the simplified M1. The Thompson was still expensive and slow to produce. Therefore, the U.S. developed the M3 submachine gun or "Grease Gun" in 1942, followed by the improved M3A1 in 1944. While the M3 was no more effective than the Tommy Gun, it was made primarily of stamped parts and welded together and could be produced much faster and at a fraction of the cost of a Thompson; its much lower rate of fire made it a lot more controllable. It could be configured to fire either .45 ACP or 9 mm Luger ammunition. The M3A1 was among the longest-serving submachine gun designs, being produced into the 1960s and serving in US forces into the 1990s. France produced only about 2,000 of the MAS-38 submachine gun (chambered in 7.65×20mm Longue) before the Fall of France in June 1940. Production was taken over by the occupying Germans, who used them for themselves and also put them into the hands of the Vichy French. The Owen Gun is a 9 mm Parabellum Australian submachine gun designed by Evelyn Owen in 1939. The Owen is a simple, highly reliable, open bolt, blowback SMG. It was designed to be fired either from the shoulder or the hip. It is easily recognisable, owing to its unconventional appearance, including a quick-release barrel and butt-stock, double pistol grips, top-mounted magazine, and unusual offset right-side-mounted sights. The Owen was the only entirely Australian-designed and constructed service submachine gun of World War II and was used by the Australian Army from 1943 until the mid-1960s, when it was replaced by the F1 submachine gun. Only about 45,000 Owens were produced during the war for a unit cost of about A$30. While most other countries during World War II developed submachine guns, the Empire of Japan had only produced one, the