# Villar Perosa aircraft submachine gun

The Pistola Mitragliatrice Fiat Mod. 1915, commonly nicknamed the Villar Perosa, was an Italian portable automatic weapon developed during World War I by the Officine di Villar Perosa.
As it was designed to use 9×19mm ammunition, it is said to be the first submachine gun, although not a true submachine gun by modern standards. Due to its extremely high rate of fire, it was nicknamed Pernacchia (literally raspberry, in that context meaning something like fart gun) by its operators.

## Design

The Villar Perosa was designed as a portable double-barrel machine gun firing a handgun round. It consisted of two independent coupled weapons, each with its own barrel, firing mechanism, and separate 25-round magazine.
Sighting was fixed and poor, and it suffered from extreme handling issues during automatic fire due to lack of a stock or any position at which to hold the weapon. As result, it could not be shouldered and fired, and this regard it failed at being an assault weapon.
The Villar Perosa operated on a delayed-blowback action. On the forward part of each bolts is an extension housing a guided slot. These slots are engaged by a lug which cause the bolts to rotate 45° upon firing. The bolt's retraction is delayed by the inertia forced by the lug as the bolt rotates. Both bolts ride on a spring-loaded guide rod.
All weapons of the Villar Perosa family, including the O.V.P. submachine gun and Revelli-Beretta carbine, were originally intended to fire a variant of the 9mm Glisenti cartridge, known as Glisenti M.915 "Per Mitragliatrici" ("For Machine-Guns"). This was a higher-velocity version of the standard Glisenti cartridge with an over-powder wad, designed to improve the penetration abilities of the weak base cartridge.
The original patent was filed in April 1914 by Abiel Bethel Revelli, a Piedmontese officer who was active in designing most of the Italian Army's automatic weapons in the early 20th century.
Before World War I, the Bersaglieri were supplied by a small factory near Pinerolo, known as Officine di Villar Perosa (O.V.P.). This company was a subsidiary of FIAT operated by Roberto Incerti. O.V.P. was primarily contracted to manufacture bicycles, but later the Bersaglieri commissioned them to produce automatic weapons designed by Abiel Revelli. They placed an order for 6,000 Genovesi-Revelli automatic rifles in 1910, but only 150 were built since the weapon underperformed and was cancelled. The Villar Perosa submachine gun was developed by Revelli in the following years, and it would seem to have offered a solution to the Bersaglieri's problem, photographs show a Villar Perosa experimentally mounted to the handlebars of a bicycle.

## Operational history

In early 1915, O.V.P. produced a trial batch of Villar Perosas and submitted them to the Army for testing. The weapon was accepted into service and an immediate order was placed. When Italy entered World War I that year, the Army suffered a shortage of machine guns (At the time only obsolete 1886 Gardner guns, 150 Perino machine guns, and a few Maxim guns were in service). The Fiat-Revelli and the Villar Perosa were the only domestically-produced machine guns, and the demand ramped up significantly. Production in the first year fell short, with only about 200 - 400 Fiat-Revellis being turned out, and about 350 Villar Perosas. The Italian Air Force (then a wing of the Army) had virtually no machine-guns and a few hundred of the first Villar Perosas were issued to them - giving rise to the myth that it was designed as an aircraft gun.
The weapon was originally issued with a gun shield.
The Villar Perosa was first issued to the infantry in 1916, with mixed results.
The Austro-Hungarians first encountered the weapon at the Battle of Asiago in May 1916. Although only a few hundred Villar Perosas were in frontline service initially, the number swelled up to about over 2,000 by the end of 1916 and it became increasingly common for Austro-Hungarian troops to come under attack from Italian troops wielding this new weapon.
The weapon was light and easy to transport in the terrain of the Alpine Front, but troops were initially not given training with it and officers had no idea how best to field it. The weapon was used almost exclusively as a defensive machine-gun on trench lines and observation points for most of 1916. In this role it would have almost certainly been inadequate, as it lacked the range, accuracy, capacity and firepower of a proper machine gun.
As the war progressed, training for the gun was introduced and infantrymen trained on the Villar Perosa were issued a shoulder patch to signify that they had experience with the weapon, in accordance with a practice in the Italian Army to issue patches that illustrated the machine-gun that a gunner was trained with.
By 1917 the newly formed Arditi shock troops pioneered assault tactics with the weapon. It was well liked due to its high rate of fire and its weight (it was very light for a support weapon), and went under various modifications: Lt. Col. Giuseppe Bassi personally designed a carrying system (consisting of a leather belt fixed to the handles that was later arranged behind the gunner's neck) to enhance Arditi performances in battle. In his idea, a section of 8 (later 16) VP machine guns had to support the attack of 20 to 30 Arditi armed with rifles, daggers and hand-grenades, giving adequate suppressive fire and striking the enemy on a psychological level as well. Each weapon was manned by 4 people: a shooter with a backpack or a shoulder ammo bag and 3 ammo carriers, who could take with them up to 5000 rounds.
Also in 1917, a bipod was introduced to replace the obsolete shield mount, for which the gun was originally designed.
A tripod mount was also developed, which could be fitted to the flexible pintle seen on the aerial service Villar Perosas. The Italian government contracted the Canadian General Electric company of Toronto to produce the tripod-mounted Villar Perosas; why Canada was approached is not entirely known. This version of the Villar Perosa lacked the central sighting ring, and used an elevated fore-sight fixed onto the barrels, with a circular rear-sight above the spade grips. These Villar Perosas were probably used for defensive fixtures and mounted on vehicles.
Some VP machine pistols were equipped with a wooden stock, though the firing mechanism remained unaltered and was not modified in the fashion of, for example, the Carabinetta Automatica O.V.P or the Moschetto Automatico Revelli-Beretta Mod. 1915.
By 1917 the Austrian Sturmbataillons were being trained with captured Villar Perosas.

## Legacy
### Italian derivatives

The mechanism of the VP was a sound design, and shortly after the end of the war was used as the basis of more practical weapons, such as the Carabinetta Automatica O.V.P and the Moschetto Automatico Revelli-Beretta Mod. 1915.

### British Trials

On the 7th of October 1915 Mr. Bernachi a representative from Officine di Villar Perosa, demonstrated a 9mm Villar Perosa at the School of Musketry in Hythe. A report describing the gun as "two long-barreled automatic pistols connected together", was forwarded to the Small Arms Committee, who expressed an interest in this gun. On the 18th of October, the SAC tested the same Villar Perosa at Enfield. It performed rather well and was considered to be an ideal gun for trench warfare. The SAC report referred to the gun as the "Villar Perosa Machine Gun", the first known use of the now-ubiquitous name for the gun (In Italy, the Villar Perosa was known only as the "Revelli" or the "Fiat").
When approached by the SAC over the requirement of a submachine gun by the British Army, the General Headquarters in France responded in late January 1916 with a clear refusal. This would mark the beginning of the British Army's reluctance to engage with the submachine gun concept until 1940.
Later in 1916, after O.V.P. developed the pintle mount for the Villar Perosa, they sent a prototype to Britain chambered in the .455 Webley Auto cartridge. Only one such example was ever made and is today in the National Firearms Center in Leeds. This gun fed from straight magazines which were windowed across the sides rather than the back. It was probably intended for aerial use, but there appears to have been no interest from the Royal Flying Corps.

### Sturmpistole

Feeling that the M.12/P16 machine pistol was not a suitable counter, the Austro-Hungarians began designing SMGs that would give equivalent performance to the Villar Perosa.
By February 1917, several prototype designs that met this requirement had been developed. These included submissions by ŒWG of Steyr, FÉG of Budapest, and Škoda of Plzeň. The designs by ŒWG and FÉG centered around the idea of tethering two machine pistols together onto a central mount to mimic the Villar Perosa, but they bore no similarity to the Italian weapon on a technical basis. The FEG factory developed unusual contraption consisting of two Frommer machine-pistols mounted upside-down onto a tripod, with remote trigger mechanisms mounted to a pair of spade grips.
Škoda decided that it would be simpler to directly reverse-engineer the Villar Perosa and manufacture a straight copy, which would be almost interchangeable with the original. In March that year, Škoda delivered their first batch of experimental guns - which they called the 'Sturmpistole' ('Assault Pistol') - to the K.u.K. Artillerie-Arsenal in Vienna, and trials were carried out over the coming months. A conclusion was reached in about August or September 1917, in favour of the Škoda gun, an order for 50 Sturmpistolen was placed by K.u.K. Kriegsministerium in anticipation of field trials at the planned Caporetto offensive.
The Sturmpistole was chambered in 9x23mm and fed from 25 round straight magazines. Although this weapon was essentially a copy of the original Italian gun, the construction was different and the parts were not necessarily interchangeable. The Sturm-Pistole was fitted to a wooden tray mount similar to the one used by the Arditi.
The first Sturmpistolen were delivered in October and issued in batches of ten to Gebirgsschützenbataillonen (Mountain Battalions) in the Mrzli-Vodil sector outside Caporetto. Almost immediately, issues with the weapons were reported; the magazines were unreliable. One battalion, under a Captain Prasch, reported that only one of the ten guns they received was fully operational,indicating that they may have been rushed into service without proper testing. Additionally, the new weapon and its faults were disclosed by two Czech deserters from Captain Prasch's battalion on the 19th or 20 October. There exists a photograph from the second day of the offensive depicting two of these guns being fielded by Austrian machine-gun crews, with the caption "Sturm-Pistolen".
Some Sturmpistolen and Villar Perosas were retained by the independent Czechslovakian Army, but were generally only kept in storage and not issued.

### German research

The Germans were familiar with the Villar Perosa prior to the development of the MP 18,I. The Austro-Hungarians had captured quantities of the weapon over the course of 1916, and by March 1917, the Austrian Sturmbataillons - trained by German instructors - were training with Villar Perosas. It is likely that the Austrians would have introduced the Germans to this weapon. Additionally, the capture of some 2,200 Villar Perosas at the Battle of Caporetto, furnished both the Austro-Hungarian and German forces with a large pool of submachine guns to study and, in fact, issue to their own troops.
German assessments of the Villar Perosa appeared in Die Technik im Weltkriege (1920) and Die militärischen Lehren des grossen Krieges (1923). No solid connection can be made between the Villar Perosa and the MP 18,I, but the Germans were certainly aware of this Italian submachine gun, and were presumably aware of the efforts that Austria-Hungary made to replicate it since 1917. It is possible that German studies into the submachine gun concept during the First World War were partially inspired by the use of submachine guns by the Italian and Austro-Hungarian armies prior to 1918.

### Kulometná Pistole Netsch

The 'Kulometná Pistole Netsch', designed by a former engineer of the Škoda plant, Josef Netsch, was a single-barreled automatic with a buttstock which employed the same bolt design and locking mechanism as the Villar Perosa. Netsch was doubtlessly influenced by Škoda's work on the Sturmpistole. Several variations of his carbine were tested by the Czechoslovakian Army in 1919, but it was not adopted.

## Users

* Italy
* Austria-Hungary: Captured examples, Sturmpistole
* Czechoslovakia
* Germany: Captured examples
* United Kingdom: Trial purposes, chambered in .455 Webley Auto