M3 submachinegun, 9mm
Official wording
U.S. M3 submachinegun, cal. 9mm Parabellum, as originally produced by the U.S. Government, having no manufacturer's name or S/N and originally marked U.S. 9mm SMG on the left side of the magazine housing, original production only.
What this entry requires
- ATF REQUIRESMarkings as the ATF wording states: “having no manufacturer's name or S/N and originally marked U.S. 9mm SMG on the left side of the magazine housing”
- ATF REQUIRESMade or imported as stated: “as originally produced by the U.S. Government”
- ATF REQUIRESYour serial number is one ATF listsATF: “having no manufacturer's name or S/N and originally marked U.S. 9mm SMG on the left side of the magazine housing, original production only”
- INFOATF states no date; production was about 1943–1945.
- INFOStill an NFA firearm; only registered examples transfer, with ATF approval (26 U.S.C. 5812, 5861).
Editorial facts · Our research
- Country
United StatesBasis: the ATF wording - Manufacturer
- Guide Lamp Division, General MotorsBasis: outside reference ¹
- Type
- SMGBasis: the ATF wording
- Action
- Select-fire / autoBasis: the ATF wording
- Caliber
- 9mm ParabellumBasis: the ATF wording
- Made
- Original production only · c. 1943–1945production; ATF states no dateBasis: estimate ²
- Service
- Military
Source
- Official wording
- ATF P 5300.11, April 2025 edition · Section IV · PDF p. 89 ↗ · ATF original ↗
- Entries
- 1 line
- Verbatim check
- Checked against the PDF text before every release
- Editorial facts
- Confidence: Medium · Last revised 18 October 2026 (Evidence pass) · How we rate confidence
- References
- 1. Wikipedia, “M3 submachine gun” ↗, maker: 'Around 1,000 M3 submachine guns in caliber 9 mm Parabellum were built by Guide Lamp'; marked 'U.S. 9 mm S.M.G.' on the left of the magazine well, without model designation
- 2. Wikipedia, “M3 submachine gun” ↗, years (estimate: partly supports it): the original 9 mm guns were delivered to the OSS in 1944; Guide Lamp produced the M3 between 1943 and 1945; the 9 mm guns' own build dates not stated
- Fact tags
- ATF the ATF wording states it.
- REF ¹ an outside reference supports it; the number points to the list of references.
- ESTIMATE an approximate or indirect reading, for example the production range of the base model.
- NO CITATION we haven’t attached a reference for this fact; it’s our editorial reading, not ATF’s.
- Source checked
- 20 October 2026: ATF’s page still lists the April 2025 edition
- Corrections
- 1 change · see below
Correction history
- Evidence passMaker: U.S. Government → Guide Lamp Division, General Motors. The M3 article says the ~1,000 original 9 mm M3s were built by Guide Lamp
Historical context
Image: Wikimedia Commons, “M3-SMG.jpg” by Curiosandrelics, CC BY-SA 3.0. Retrieved October 2026.
Summary: Wikipedia, “M3 submachine gun”. Text CC BY-SA 4.0.
FROM WIKIPEDIA
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.