This is a really early underhammer pinfire pistol made in 1849 by the French gunsmith, Joseph-Célestin Dumonthier who lived in Houdan, Seine-et-Oise, France. It follows his 2 July 1849 French patent.
The whole barrel unscrews from the frame and allows you to load a single 12mm pinfire cartridge.
TEMPS DE LECTURE: 1 min