M3 Grease Gun
Country: 
United StatesManufacturer: General Motors (Guide Lamp Division)
Low-cost .45 ACP submachine gun introduced in 1943 to replace the Thompson: stamped sheet metal, wire stock and reduced rate of fire for better control.
M3 Grease Gun
Community
Data trust
- Reliability
- Unverified
- Sources
- Sources pending review
Identity
- Designation
- M3 Grease Gun
- Alias
- Grease Gun
- Manufacturer
- General Motors (Guide Lamp Division)
- Country
- United States
- Year
- 1943
- Category
- Submachine gun
- Status
- Historic
Ballistics
- Caliber
- .45 ACP
- Muzzle velocity
- 280 m/s
- Rate of fire
- ~450 rpm
- Effective range
- 90 m
- Maximum range
- 200 m
Dimensions
- Barrel length
- 203 mm
- Overall length
- 570 / 745 mm
- Empty weight
- 3.7 kg
Mechanics
- Operating system
- Blowback
- Bolt / action
- Unlocked bolt, open-bolt fire
Feed
- System
- Double-stack magazine
- Standard capacity
- 30 rounds
Fire modes
Historical profile
Development
The M3 submachine gun was designed in 1942 by George Hyde at General Motors to replace the expensive Thompson in American war production.
Adopted in December 1942, it was designed to be produced rapidly via sheet-metal stamping and welding, with minimal machining.
Design
Nicknamed 'Grease Gun' for its resemblance to a mechanical grease gun, it operates on open-bolt blowback in .45 ACP, fed by double-stack 30-round magazines.
The 1944 M3A1 version further simplified the mechanism by removing the cocking handle, replaced by a finger hole directly in the bolt.
Operational service
Issued to armored vehicle crews, paratroopers and special forces in World War II, it was also used in Korea and Vietnam.
It remained in U.S. service into the 1990s as a sidearm for M1 Abrams tank crews, thanks to its compactness.
Variants
Main users
United States · Philippines · South Korea · Argentina
Key components
- ●Stock — Shoulder rest.
- ●Receiver — Weapon body with internal mechanisms.
- ●Grip — Primary grip.
- ●Magazine — Cartridge feed.
- ●Barrel — Guides the projectile.
