The Mitrailleuse was one of the first pseudo-machine guns – the first ones were developed prior to the Gattling, but they continued to be purchased by military forces through the 1870s. There were several versions, the two most common being the Reffye and Montigny designs. We are taking a look at the Montigny today, which used a cluster of 37 barrels, each chambered for a 10-12mm caliber cartridge (the specific cartridge would depend on the request of the buyer).
The Montigny used a removable cartridge plate for loading, which allowed it to maintain a very high rate of fire (as long as loaded plates were available to the gunners). The breech was a large block containing 37 separate firing pins, which the cartridge plate attached to the front of. A large lever at the rear of the gun connected to a knee-joint type cam that would push the breechblock forward, chambering the 37 cartridges and locking the breechblock in place. A second lever on the side of the gun would then be pulled up vertically, firing the barrels in succession.
The firing mechanism was quite simple. When the breechblock was pulled rearward, all of the firing pins would be cocked against their own individual springs, and a plate would slide up between the firing pin and its port in the front of the breechblock. The firing lever simply pulled that bloacking plate downward, allowing the firing pins to snap forward against their cartridges in sequence. The rate of fire would be determined by the speed with which the firing lever was pulled, and could be as slow as single shots if the gunner was careful.
Once the cartridges had all been fired, the rear lever would be used to unlock the breech and pull it backwards. The cartridge plate (now full of empty cases) would be pulled out the top of the gun, and a fresh loaded one put in its place. This sequence would be repeated as desired until the gun overheated or ammunition ran out.
The Mitrailleuse as a general type of firearm saw only one major combat usage, and that was the Franco-Prussian War of 1870-1871. The French had adopted the Reffye Mitrailleuse (which had 25 barrels, and a screw-type locking mechanism instead of Montigny’s knee joint, but were otherwise similar for practical purposes) and considered it a game-changer. Unfortunately for the French, the tactical understanding of how to use a weapon like the Mitrailleuse was still totally lacking. The guns were treated like artillery, and used to fire at ranges of 1500m or more against German troops. The sights on the Mitrailleuse were simple post and notch affairs like rifles of the day, and the extreme range called required excellent range estimation (which the gunners were not trained for). To compound the problem, the combination of long range and small projectiles made it nearly impossible to observe point of impact when firing, and it was nearly impossible to actually hit targets as a result.
The problems with French use of the Mitrailleuse were compounded by the secrecy surrounding the guns. The Army was so focused on preventing the Germans from discovering the guns that virtually no training was given to troops on their use – few had even seen them prior to battle.
As a result of their utter failure to provide the French Army with an advantage, a general feeling of the inferiority of all such rapid-fire rifle-caliber weapons would permeate military culture for several decades. Ultimately, it was only the use of Maxim guns in WWI that would change the minds of generals and ordnance departments worldwide (although the forward-looking few did learn from conflicts like the Russo-Japanese War).
This particular Mitrailleuse is Belgian, made by Christophe & Motigny: