They're from the 1800's and where nicknamed 'petite protectors', designed for discreet protection like the Deringer, walking stick guns, that kind of thing.
You could get 2mm pinfire or 4mm pinfire ammo versions.
Thought it was pretty cool

Noisydad wrote:Wonder what a 2mm pin fire would do other sting lke one our mozzies and make your assailant really, REALLY annoyed?