The Mitragliatrice Leggera SIA Modello 1918,[1] also known as the SIA Mod. 1918, is an Italian air-cooled aircraft-mounted light machine gun.[2]


In approximately 1915 or 1916, the Villar Perosa was introduced into service, laying the foundation of certain new combat techniques and was suitable enough to be adopted by the Arditi. However, problems were found with the Villar Perosa, owing to its unique construction.

In 1918, Col. Abiel Bethel Revelli proposed a design of machine gun chambered in 6.5mm Carcano to the Royal Italian Army, and designed a prototype machine gun for that purpose which he submitted for testing. The first prototype of his design was rejected, with Revelli asked to make improvements to the weapon, mainly involving the shortening of its barrel and other minor changes.

His next prototype incorporated the improvements recommended by the Royal Italian Army was named the SIA after its manufacturer; he submitted it to the Army again, where it was accepted into service and adopted as a weapon to complement the Villar Perosa as opposed to replacing it.[2] Despite there being attempts to convert the Villar Perosa into a viable handheld weapon, the Army decided to give priority to Col. Revelli's new design.

The SIA was meant to be armed by small combat units for ambushes, but was most notably used as a mounted machine gun mounted on aircraft and some light tanks like the FIAT 3000. The SIA was meant to be distributed evenly amongst companies, with each company receiving eight SIAs with two SIAs being used by each platoon. The SIA saw extremely limited use by the Italians in World War II.

Production ended in 1923 after about 18,000 were produced.[3] It is said that the weapon was used up until at least 1943 when it was distributed to rearmost troops, coastal battalions and the Blackshirts. A few exemplars of the SIA survive today.

Design DetailsEdit


How the SIA Mod. 1918 is supposed to be transported.

The SIA is a blowback-operated machine gun fed from a top-mounted dual-stack magazine made of sheet steel that holds fifty rounds. The weapon's barrel is made of nichrome steel and has a prominent aluminum barrel jacket with fifty-two rings machined around the it to facilitate cooling and held together with a locking clasp. The barrel is said to permit a two-hundred round burst of continuous fire.

The top-mounted magazine, while rather normal for the time, did pose a few problems for this weapon system; the main problem with the position of the system was that it made the weapon very easily identifiable, effectively giving away the position of the gunner and the weapon's crew. In addition, the magazine added bulk to the weapon and made it slightly harder to transport. A colonel of the Italian Army is quoted as saying that "the weapon's shortcomings were quickly apparent due to it being hastily designed".

The weapon's sighting system is located on the left side of the receiver; the system is mounted on a lift which is raised or lowered by means of a knob; the knob can be adjusted to distances from 300–1,000 metres (980–3,280 feet; 330–1,090 yards). The weapon features spade grips and a button in the middle of the grips fires the weapon. The weapon's charging handle is located on the right side of the weapon, with the weapon ejecting from the bottom. A reinforced wooden tripod is featured on the bottom of the weapon which can be folded up to make the weapon more portable; the weapon is designed to be slung around its operator's back.


  • The SIA is regarded as being the first air-cooled light machine gun produced in Italy.[2]


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