The LifeCard - a .22LR credit card-sized single-shot pistol. From Trailblazer firearms. Admittedly thicker than a credit card, but it fits in an Altoids tin, which is a common DIY form factor. $400.
1:02 video:
More: LifeCard .22LR | Trailblazer Firearms
Previously:
https://www.homemadetools.net/forum/...877#post105666
9mm mini cannon - GIF
Miniature hunting knife made from stainless steel bolt - video
Mini cannon - GIF
Punt guns - enormous old shotguns for hunting waterfowl
Bookmarks