Lefaucheux M1858

The Lefaucheux M1858 was a French military revolver developed for the navy, chambered for the 12 mm pinfire cartridge, and based on a design by Casimir Lefaucheux and his son, Eugene (also a gun designer), it holds the distinction of being the first revolver using metallic cartridges to be adopted by any armed service. The basic Lefaucheux design was adopted by several European countries, copied and improved over the years before being replaced by centerfire revolvers in the late 19th century.

Design

The Lefaucheux is a six-shot open framed design, loaded via a hinged gate on the right side of the frame, through which empty cartridges are also ejected via an ejector rod running along the barrel. The cylinder is notched to accommodate the pinfire cartridges exposed pin which sets off the primer charge when struck by the hammer. A protective shroud was added to the recoil shield to prevent accidental discharges. The revolver originally used a single-action trigger, but by 1865, double-action versions were also introduced.

Ammunition

Most service handguns were chambered for a 11 mm cartridge, while the numerous copies made by Belgian and French gunmakers were chambered in calibers ranging from 7 mm to 12 mm. According to Walter, revolvers imported by the United States during the Civil War fired a 12 mm cartridge loaded with 9.7 grains (0.63 g) of black powder and a 208 gr (13.5 g) bullet at 160 m/s (540 ft/s).

While the pinfire cartridge is prone to accidental discharge if handled carelessly, it did have the advantage of being more resistant to moisture than the loose powder used by percussion cap revolvers, while the copper or brass case also provides a gas seal and is reloadable.

In 1870, the French converted their revolvers to fire 11 mm centerfire cartridges loaded with 12.3 gr (0.80 g) of black powder and a 128 gr (8.3 g) bullet at 215 m/s (710 ft/s), similar to the ammunition used on the MAS 1873 revolver, but slightly longer.