This unique breechloader began life as a Harpers Ferry Model 1842 percussion musket, a .69 caliber smoothbore muzzle-loader manufactured in 1855. Wohlgemuth completely overhauled the musket into a break-action breech-loading firearm. He fitted a hinged breech mechanism into the original stock and barrel, allowing the barrel to tip downward for loading, much like a shotgun. To secure the breech when closed, the original trigger guard was reversed and a cam-locking lever was added under the action. He also modified the nose of the percussion hammer to be better suited to strike the pins of the pinfire cartridges, and trimmed the wooden fore-end to accommodate the new hinge. Finally, an M1861 Springfield rifle-musket rear sight was installed on the barrel, giving the converted gun proper sighting for rifled fire. Each of these alterations was performed by Wohlgemuth himself, transforming the old muzzle-loader into a modern breech-loader while retaining its hefty .69″ bore, which closely matches the dimensions of a 12-gauge shotgun.