M3 Submachine Gun

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	Weapon: M3 Submachine Gun Type: Submachine Gun Country of Origin: United States Year Adopted: 1943 Caliber: 45 ACP Action: Blow Back Fully Automatic Overall Length (mm): 760.0 Weight (kg): 3.00 Effective Range (m): 100

The M3 Submachine Gun, commonly known as the "Grease Gun" due to its resemblance to the mechanic's tool, was designed as a cost-effective and simplified alternative to the Thompson submachine gun. Developed in 1942 by the U.S. Army's Ordnance Department, the M3 was chambered in .45 ACP and featured a stamped steel construction, which reduced production costs and assembly time. The design emphasized simplicity, utilizing a straight blowback mechanism and a basic tubular frame, which contributed to its reliability in the field.

Production of the M3 began in 1943, with around 700,000 units produced by the end of World War II. Initially manufactured by General Motors' Guide Lamp Division, the M3 was later upgraded to the M3A1 variant, which eliminated the external cocking handle in favor of a more streamlined design. The gun saw extensive service during WWII, favored by American tank crews, paratroopers, and support personnel due to its compactness and ease of handling in confined spaces. Its service continued through the Korean War and even into the Vietnam War, where it was praised for its durability and effectiveness in close-quarter combat.

The M3 Submachine Gun earned a mixed reputation over its decades of service; it was both respected for its practicality and criticized for its crude appearance. Its low production cost, reliable performance, and ease of use made it a mainstay in the U.S. military's arsenal well into the 20th century, symbolizing the efficiency-driven design ethos of wartime manufacturing. The M3 remains an iconic firearm, remembered for its role in equipping Allied forces and as a symbol of American industrial adaptation during World War II.