Key facts
- Type
- Submachine gun
- Place of origin
- United States
- In service
- 1943–present
- Used by
- See Users
- Designer
- George Hyde
- Manufacturer
- General Motors , others
- Unit cost
- Approx. US$ 20 (1943; equivalent to $279 in 2025)
- Produced
- 1943–1945; early 1950s
- Number span no built
- Total: 655,363 M3: 606,694 M3A1: 48,669
- Variants
- M3A1 PAM1 PAM2 T29
- Mass
- M3 (empty): 8.15 lb (3.70 kg) M3A1 (empty): 7.95 lb (3.61 kg)
- Length
- 29.1 in (740 mm) stock extended / 21.9 in (556.3 mm) stock collapsed
- Barrel length
- 8 in (203.2 mm)
- Cartridge
- .45 ACP (11.43×23 mm) 9×19mm Parabellum .30 Carbine (7.62×33mm)
- Action
- Blowback , open bolt
- Rate of fire
- 450 rounds/min cyclic (= 7 1 ⁄ 2 / second)
- Muzzle velocity
- 900 ft/s (274 m/s)
- Effective firing range
- Sights fixed to 100 yards (91 m)
via Wikipedia infobox
~29 min read
Encyclopedic overview
The M3 is an American .45-caliber submachine gun adopted by the U.S. Army on 12 December 1942, as the United States Submachine Gun, Cal. .45, M3. The M3 was chambered for the same .45 ACP round fired by the Thompson submachine gun, but was cheaper to mass produce and lighter, at the expense of accuracy. The M3 was commonly referred to as the "Grease Gun" or simply "the Greaser", owing to its visual similarity to a grease gun, a mechanic's tool.
The M3 was intended as a replacement for the Thompson submachine gun, and began to enter frontline service by mid-1944. By late 1944, the M3A1 variant was introduced, which also saw use in the Korean War and later conflicts.
Excerpted from Wikipedia’s “M3 submachine gun” article, available under the CC BY-SA 4.0 licence.