C&R · III · 062
Invisible Defender palm gun
Section III: removed from the NFA, curio or relic under the GCA
Official wording
ATF P 5300.11 · APRIL 2025 EDITION · SECTION III · VERBATIM · PDF P. 25 ↗
Invisible Defender four barreled palm gun, cal. .22, manufactured by O.F. Mossberg, Chicopee Falls, Massachusetts, circa 1902 – 1909.
What this entry requires
- ATF REQUIRESMade or imported as stated: “manufactured by O.F. Mossberg”
- ATF REQUIRESMade 1902–1909 (ATF’s dates)ATF: “circa 1902 – 1909”
Editorial facts · Our research
- Country
United StatesBasis: no citation - Manufacturer
- O.F. Mossberg, Chicopee Falls, MABasis: the ATF wording
- Type
- PistolBasis: outside reference ¹
- Action
- OtherBasis: no citation
- Caliber
- .22Basis: the ATF wording
- Made
- 1902–1909Basis: the ATF wording
- Service
- Commercial
Source
- Official wording
- ATF P 5300.11, April 2025 edition · Section III · PDF p. 25 ↗ · 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. web.archive.org ↗, type: RIA (archived): "Invisible Defender", four-shot, palm pistol ... hinged, four shot, barrel cluster with squeeze trigger; Type: Pistol (RIA attributes it to C.S. Shattuck 1907–1915; ATF says O.F. Mossberg, circa 1902–1909, and ATF stands)
- 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
- None
Historical context

Image: U.S. Patent 837,867, “Pistol, sheet 1” by Oscar F. Mossberg, Public domain (US patent). Retrieved October 2026.