After the outbreak of World War II, in order to meet the growing demand for submachine guns, the US military simplified and improved the M1928A1 Thomson submachine gun, designed the M1 Thomson submachine gun for mass production, and later further simplified the M1 and designed the M1A1 Thomson submachine gun.
Although the US military has repeatedly simplified and improved the Thomson submachine gun, it has not achieved significant results in improving its production performance, because many parts of the Thomson series submachine gun are made through complex cutting processing, which is time-consuming and labor-intensive. In parallel with the improvements to the Thomson series of submachine guns, the U.S. Army conducted comparative tests of various submachine guns at the Aberdeen Range, which specializes in testing U.S. Army weapons. In this comparative experiment, in addition to the submachine gun of the United States at that time, a wide range of submachine guns produced in European countries were also widely collected, and comparative experiments were carried out in terms of performance, operability, and productivity, including submachine guns captured from the German army.
The M3 submachine gun is a low-cost .45 caliber submachine gun mass-produced by the American General Motors Company during World War II. It entered service on December 12, 1942, replacing the expensive Thompson submachine gun. Because of its appearance, it looks like a lubricating oil gun for the car (butter), also known as the m3 oil injection gun.
After the outbreak of World War II, in order to meet the increasing demand for submachine guns, the US military simplified and improved the M1928A1 Thomson submachine gun, designed the M1 Thomson submachine gun for mass production, and later further simplified the M1 and designed the M1A1 Thomson submachine gun. Although the US military has repeatedly simplified and improved the Thomson submachine gun, it has not achieved significant results in improving its production performance, because many parts of the Thomson series submachine gun, including the receiver, are made through complex cutting processing.
The receiver of the m3 submachine gun is welded into one by the left and right half of the casing formed by stamping, and the parts such as the re-entry spring and the bolt are all loaded from the front of the receiver, and the trigger, resistance and other parts are also stamped. As a result of the widespread use of stamping parts in the m3 submachine gun, the production performance of the gun exceeded that of any previous submachine gun. The right side of the m3 gun is equipped with a pull handle for operating the backward movement of the gun in the rear part of the magazine, and the pull handle is a rotating structure, and when it is rotated backwards, the "l" type transmission rod in the pull handle will push the gun back. The rear end of the m3 is equipped with a retractable stock bent with thick steel bars, and a stock retention pin that crosses the rear section of the gun, which can be fixed in both the pull and retract positions.
Turn the pull handle backwards, and the "l" drive rod in the pull handle box will push the bolt backwards. Taking into account the supply to the United Nations and anti-German guerrillas in Europe, the M3 was also specially equipped with a caliber conversion kit for practical 9 mm x 19 cartridges. Replaced with this kit, it can fire 9 mm x 19 bullets and use the magazine of the British Stern submachine gun, and the caliber conversion kit consists of a magazine conversion sleeve for the bolt, barrel and magazine insertion. The M3 submachine gun with caliber conversion kit was once supported for guerrilla use under German occupation.
The U.S. Army decided to look for a new submachine gun that performed better than the M2. In October 1942, the U.S. Army Department of Technology officially advanced the development plan for a new submachine gun, and the new submachine gun developed became the later M3 submachine gun. Development was not the responsibility of a single technician, but around the United States Army Major René R. Statella, and the development team led by GM's chief engineer in-country, Fretlik W. S. S. Sintson, advanced the design, with the assistance of various technicians.
The main goal of the new submachine gun is "to have the best production performance", that is, it must be easy to produce in large quantities. The original prototype was designed and produced within General Motors, and the most important and referenced in the design process was the British Stern submachine gun. The British Stern submachine gun, which used a large number of stamping parts and welding processes, was the lowest production cost at that time, which was convenient for mass production.