Here are 4 variations of 12mm pinfire percussion adapters. These have a tapered “pin” to allow them to fit in an unmodified 12mm pinfire revolver. The screw on the bottom of the three, unscrews to allow cleaning by pushing something all the way through from the pin. These could be used with readily available caps and balls and powder when a supply of pinfire cartridges ran out.
Adams & Lefaucheau pinfire revolver. Charles Fusnot, of Bruxelles, Belgium is the manufacturer of the cartridges: http://freemycollection.com/?page=manufacturers&id=17&name=Charles-Fusnot-Fabrique-de-Balles-et-Cartouches
Cartridge board at the Dutch Police Museum. it was made by Staatsbedrijf der Artillerie-Inrichtingen and donated in 1920 to the now closed Genootschap voor een Politiemuseum. On the bottom it shows the 12mm ball load and shot load pinfire cartridges that were made for the Dutch Customs officials (grenscommiezen) at the borders.
10g pinfire alarm gun. The left side of the massive muzzle is marked "SALMON" inside a box with "DEPOSE" underneath. There is a large spring that acts as the hammer with a notched lever with a hole at the top as the trigger. There is a swiveling breechblock that has a smaller block on top to act as a safety.
Manufactured in Paris, France, this weapon combines a short bladed sword with a six-shot pepperbox revolver. 26 3/4 inches overall in length. The blade measures 18 1/2" long, with short double fullers leading to single fullers which run the rest of the length, panels of etched scrollwork on each side, an etched scene of a deer in the woods on the left ricasso and "ALFREDO HEROUARD/LIMA", the mark of a Portuguese agent and importer, on the right ahead of the revolver barrel.