According to Arsenal Firearms, their tradition of building miniature working firearms first started in 1810 under the patronage of the Russian Tsars. These half-scale or smaller firearms were perfectly capable of being shot, and were often considered the very pinnacle of a gunsmith’s ability. Of course, like a fine watch with many intricate parts, these miniatures were very hard to build and assemble. Even those crafted by the dedicated artisans at Arsenal face one big drawback: there is no ammunition designed to be fired out of these tiny firearms.
That is, at least until Larry Vickers of Vickers Tactical convinced Arsenal to make a limited amount of ammunition for the miniatures. You can watch the full four-part series of how these guns are made below, or skip straight to them being shot in part four.