A mitrailleuse (; from French mitraille, "grapeshot") is a type of volley gun with barrels of rifle calibre that can fire either all rounds at once or in rapid succession. The earliest true mitrailleuse was theorized and proposed in 1851 by Belgian Army captain Fafschamps, ten years before the advent of the Gatling gun. It was followed by the Belgian Montigny mitrailleuse in 1863. Then the French 25 barrel "Canon à Balles", better known as the Reffye mitrailleuse, was adopted in great secrecy in 1866. It became the first rapid-firing weapon deployed as standard equipment by any army in a major conflict when it was used during the Franco-Prussian War of 1870–71.
A steel block containing twenty-five 13 mm (.51 calibre) centre-fire cartridges was locked against the breech before firing. With the rotation of a crank, the 25 rounds were discharged in rapid succession. The sustainable firing rate of the Reffye mitrailleuse was 100 rounds per minute and its maximum range was about 2000 yards (1800 m), a distance that placed their batteries beyond the reach of Prussian Dreyse needle rifle fire. Reffye mitrailleuses were deployed in six-gun batteries and were manned by gunners as a form of special artillery.
Although innovative and capable of good ballistic performance, the Reffye mitrailleuse was a tactical failure because its basic concept and operational use were flawed. Only 210 Reffye mitrailleuses were in existence at the beginning of the Franco-Prussian War in 1870. Their field use was discontinued by the French Army after 1871. After the Gatling gun was replaced in service by newer recoil- or gas-operated weapons, multi-barrelled weapons fell into disuse for many decades. Some examples were developed during the interwar years but only as prototypes or were rarely used. The word mitrailleuse became the generic term for a machine gun in the French language because of its early appearance in the field of weapons, although the mitrailleuse was manually operated.
Origin
thumb|left|The 37-barrel [[Montigny mitrailleuse, which was developed in 1863.]]
The first "mitrailleuse" was a manually fired 50-barrel volley gun. It was developed in Belgium in 1851 by Belgian Army Captain Fafschamps, who made a rough prototype and drawings of his invention. The system was improved during the 1850s by Louis Christophe and the Belgian engineer Joseph Montigny, with the completion of the 37-barrel Montigny mitrailleuse in 1863. From 1859, Joseph Montigny proposed his design to Napoleon III, which led to the development of the French Reffye mitrailleuse, which was designed by Jean-Baptiste Verchère de Reffye in collaboration with Montigny, and which was adopted by the French Army in 1865. Initially kept under wraps as a secret weapon, it was widely used in battle by French artillery during the Franco-Prussian War (1870–71). Smaller numbers of other designs, including the Gatling gun, were also purchased by the French government during the latter part of that conflict. The Reffye model had initially been built in small numbers and in secrecy: only about 200 were available at the beginning of the conflict. This also kept regular French field artillery in a neglected position in the eyes of French emperor Napoleon III, with dire consequences during the Franco-Prussian War of 1870–71.
Technical characteristics
Design
thumb|Rear view of 25-barrel Reffye mitrailleuse; Musée de l'Armée
thumb|Side plan view of Reffye mitrailleuse,
Several variants of the mitrailleuse concept were developed, with common elements to all of their designs. They were characterized by a number of rifled barrels clustered together and mounted on a conventional artillery chassis or (in the case of one model) a tripod. The ammunition was secured in a single block and placed into the breech, behind the open ends of the barrels. All of the barrels were loaded simultaneously by a manual closing lever or large horizontal screw. A second lever could be worked rapidly (or in some models, a crank could be turned) to fire each barrel in succession. This earned the weapon its French nickname of moulin à café (coffee grinder). (A very similar name was earned by the hand-cranked, mechanically loaded, continuous-firing, "coffee mill gun" in America during the American Civil War.)
The ammunition plate or block had to be removed by hand before another loaded plate could be inserted. Unlike in the Gatling gun and later rapid-firing automatic weapons, the entire loading and firing process was manual. The mitrailleuse's major innovation was that it greatly increased the speed of these processes when compared to standard infantry rifles of the era.
The different variants of the mitrailleuse concept were distinguished by their number of barrels and their different calibers, as the following table summarizes.
{| class="wikitable"<!-- class="wikitable"---> style="background: azure; border: 2px solid wheat; padding: .125em; text-align:center; margin:1em"
|- bgcolor="azure"
| style="background:azure;" |Variant name || Barrels || Barrel arrangement || Caliber || Date<sup>1</sup>|| Notes
|- bgcolor="wheat"
| Fafschamps
| 50 || Clustered || || 1851 || Needle fire, paper cartridges. Prototype and drawings
|- bgcolor="wheat"
| Christophe-Montigny
| 37 || Clustered ||11 mm <br>(0.4 in)|| 1863 || Privately developed and used primarily by the Belgian Army
|- bgcolor="wheat" <!--"lightblue" "verylightblue" "lightyellow" "azure" --->
| Reffye
| 25 || In five rows (5 × 5) ||13 mm <br>(0.5 in)|| 1865 || Widely used by the French Army during the Franco-Prussian War
|- bgcolor="wheat"
| Bollée
| 30 || Two circular rings (18 in the outer ring, 12 in the inner) || 13 mm <br>(0.5 in)|| 1870 || Used by the French Army of the Loire during the Franco-Prussian War
|- bgcolor="wheat"
| Chevalier et Grenier
| 16 || Two horizontal rows (2 × 8) ||11 mm <br>(0.4 in)|| 1870 ||
|- bgcolor="wheat"
| Gabert
| 04 || Four barrels each with two chambers. While four chambers are in use, four are reloaded.<sup>2</sup> || 11 mm <br>(0.4 in)|| 1870 || Tripod-mounted, unlike the other carriage-mounted variants
|-
|colspan="6"| Notes: <small>[1]</small> Date developed <small>[2]</small> Translated from the website: www.mitrailleuse.fr/Historique/Aballes/Aballes.htm
|}
Most variants of the mitrailleuse were mounted on an artillery-style carriage. This made them heavy and cumbersome to handle on the battlefield, with gun and carriage weighing up to 900 kg (2,000 lb).
Ammunition and firing rates
The mitrailleuse's dependence on manual loading meant that its firing rate depended greatly on the skill of its operators. A skillfully manned Reffye mitrailleuse could sustain four volleys (100 rounds) per minute in ordinary operation and reach five volleys (125 rounds) per minute during emergencies. The rapidity of discharge of each individual volley (25 rounds) was controlled by the gunner's action on a small manual crank on the right side of the breech. The weapon's 25 barrels were not discharged all at once, but in rapid succession. Because it was so heavy (1,500 lbs), the Reffye mitrailleuse did not recoil during firing and thus did not need to be re-sighted on its target after each volley. This essential absence of recoil during firings was promoted by Reffye as a considerable advantage over conventional field artillery. Each regular battery of Reffye mitrailleuses lined up six guns firing together, more or less side by side.
The Reffye mitrailleuse used a 13 mm (.512 inch) centerfire cartridge, designed by Gaupillat, which represented the state of the art in ammunition design at the time. It was rather similar to an elongated modern shotgun shell: centerfire with a rimmed brass head and a dark blue hardened cardboard body. The , 13 mm (0.512 inch) patched bullet was propelled by 185 grains (12 grams) of compressed black powder at a muzzle velocity of , three and a half times more powerful than Chassepot or Dreyse rifle ammunition. This was, by far, the most potent rifle caliber ammunition in existence at the time. The Montigny and Reffye mitrailleuse systems were not designed to function with paper cartridges such as the 11 mm Chassepot combustible paper cartridge. During an early engagement of the Franco-Prussian War, at Forbach in Alsace on August 6, 1870, a Prussian general officer (General Bruno von François) was brought down by a very closely spaced volley of four bullets. According to the Prussian regimental record, those four mitrailleuse bullets had been fired from 600 meters away. French artillery attempted to rectify this problem by developing special ammunition capable of firing three bullets from the same cartridge for short-range point-defence.
In summary, the Reffye mitrailleuse was rarely used to deliver sweeping fire at close range like modern machine guns. The mitrailleuse six-gun batteries had been designed to deliver fire on targets too distant to be reached with Chassepot infantry rifles or artillery grapeshot. To fulfill this role, at least during the early weeks of the campaign, the mitrailleuses were deployed together with the older "Napoleon" muzzle loaded field guns ("canon obusier de 12") used by the French Army during the Franco-Prussian War. The mitrailleuse crews are on record of having generally objected to being placed in proximity to regular artillery batteries.
<gallery widths="200px" heights="200px">
Image:Reffye mitrailleuse mechanism.jpg|Reffye mitrailleuse mechanism
Image:Magazine plate of a Montigny Mitrailleuse.jpg|Magazine plate of a Montigny mitrailleuse, designed to hold 37 cartridges and to be slid into the breech before firing
Image:Reffye mitrailleuse bullet magazine housing.jpg|Reffye mitrailleuse bullet magazine housing
Image:Reffye Canon A Balles before 1923.jpg|Section of the 25-barrel Reffye mitrailleuse ("Canon à balles"), 1897
Image:Reffye mitrailleuse muzzle.jpg|Reffye mitrailleuse muzzle
</gallery>
Development
The mitrailleuse is best known for its service with the French Army but in fact it was first used in Belgium in the 1850s as a static weapon to defend the moats of fortresses. It was a 50-barrel needle fire, paper cartridge weapon which had been designed by a Captain T.H.J. Fafschamps. Then, after 1863, it was improved with only 37 barrels, 11×70mmR centerfire ammunition The new weapon was thoroughly tested in 1868 at the military firing range at Satory, near Versailles, in conditions of great secrecy. Due to a fear of spies, test guns were concealed in tents while being fired at distant targets. The mitrailleuse performed mechanically with remarkable efficiency and much was expected of it in a combat situation.
A total of 215 mitrailleuses and five million rounds of ammunition had been manufactured by July 1870, but only 190 were operational and available for field service when war with Prussia broke out.
Operational doctrine
thumb|A Bollée mitrailleuse and crew in action, in [[Franco-Prussian War (Illustration for The Illustrated London News magazine, 13 August 1870)]]
The French Army used the mitrailleuse as an artillery weapon, rather than an infantry support weapon—a role later filled by the machine gun. As a matter of fact, the official name of the Reffye mitrailleuse in the French Army was "le Canon à Balles", a designation that translates literally as: "cannon that fires bullets":
Having been developed by the artillery they were, naturally, manned by artillerymen and attached to artillery groups equipped with regular four-pounder field guns. Each mitrailleuse battery comprised six guns, each with a crew of six. One man on the front right fired the gun while another man on the front left swiveled the gun sideways for sweeping fire. The four other men attended to aiming, loading, and unloading. Auguste Verchère de Reffye himself consistently viewed the mitrailleuse as an artillery weapon: