C&R · IV · 204
SS1 Sidewinder machineguns
Section IV: still an NFA firearm, also a curio or relic
Official wording
ATF P 5300.11 · APRIL 2025 EDITION · SECTION IV · VERBATIM · PDF P. 87 ↗
SS1-Sidewinder machineguns, serial numbers Ex-001 through Ex-0015 and Ex-0017 through Ex-020.
What this entry requires
- ATF REQUIRESYour serial number is one ATF listsATF: “serial numbers Ex-001 through Ex-0015 and Ex-0017 through Ex-020”
- INFOATF states no date; production was about 1976–1979.
- INFOStill an NFA firearm; only registered examples transfer, with ATF approval (26 U.S.C. 5812, 5861).
Editorial facts · Our research
- Country
United StatesBasis: no citation - Manufacturer
- Not statedBasis: the ATF wording
- Type
- SMGBasis: outside reference ⁴
- Action
- Select-fire / autoBasis: outside reference ³
- Caliber
- 9mm ParabellumBasis: outside reference ²
- Made
- Listed serials only · c. 1976–1979production; ATF states no dateBasis: estimate ¹
- Service
- Commercial
Source
- Official wording
- ATF P 5300.11, April 2025 edition · Section IV · PDF p. 87 ↗ · 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. forgottenweapons.com ↗, years (estimate: partly supports it): Forgotten Weapons: designed by Sidney McQueen, developed 1966–68, interest revived in the late 1970s and "the guns were actually manufactured in the late 70s. Full production was anticipated for 1980, but that failed to materialize"
- 2. forgottenweapons.com ↗, calibers: "The SS-1 was chambered in 9mm Parabellum, the SS-2 in .45 ACP"; about 20 Sidewinders made in three models
- 3. forgottenweapons.com ↗, action: blowback from an open bolt, "progressive triggers – a short pull fires in single shot mode and a full press fires in fully automatic"
- 4. forgottenweapons.com ↗, type: "The Sidewinder is a rather unusual submachine gun", an "arm pistol" fed from Sten magazines
- 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
- 3 changes · see below
Correction history
- Evidence passEditorial confidence: Low → Medium. Re-rated after supporting references were added or re-checked.
- Evidence passYears: 1976–1980 → 1976–1979. Forgotten Weapons says the guns were made in the late 1970s and the planned 1980 production never happened
- Evidence passCalibers: Not stated → 9mm Parabellum. ATF names no caliber, and Forgotten Weapons gives the SS-1 as the 9mm Parabellum model
Historical context
NO VERIFIED IMAGE AVAILABLEWe show only freely licensed images verified to depict this model. None has been found yet.