Like artillery before it, the machine gun changed the way wars were fought. Its value was brought to the forefront in the actions concerning World War 1 (1914-1918) and all major combatants fielded some form of the weapon type through the various campaigns. Machine guns could be game-changers in the scope of offensives and provide exceptional firepower for defending strategic positions. Heading into the inter-war years, machine gun development persisted to create some of the more classic forms encountered during World War 2 (1939-1945).
Italian industry was no stranger to design, development and mass production of small arms - homegrown weapons were fielded throughout the First World War and beyond. The Italian Army's first air-cooled Light Machine Gun (LMG) offering actually emerged in the late stages of the war as the SIA Modello 1918 and this weapon featured a delayed blowback system of operation, fed from a 30-round detachable magazine (of skeletal design) inserted into the top of the receiver, and offered good firepower for its given battlefield role. It was intended to replace the Villar Perosa twin-barreled 9mm machine gun - a design which was eventually broken up and reissued as a submachine gun, a role where it proved much more effective.
Design of the Modello 1918 was attributed to Giovanni Agnelli. The firearm was chambered for the 6.5x52mm rimmed Mannlicher-Carcano rifle cartridge. Overall weight of the complete system was 10 to 15 kilograms. The internal firing operation was full-automatic-only with an impact mechanism in place and rate-of-fire reached 500 to 700 rounds-per-minute. Effective range was out to 900 meters with an absolute range of 3,000 meters. Air-cooling was required to keep the barrel from fracturing due to overheating and, to aid in this, cooling fins were added for most of the length of the barrel. A conical flash hider was fitted to the gun's "business end". The receiver was of a decidedly slim, rectangular shape and spade grips were added to the rear for the operator to control the gun.
For its role as a light machine gun, a support assembly was typically fitted as a base for the weapon on which to sit on.
Its late entry into World War 1 meant that the Modello 1918 held little impact in the conflict - production was handled under the Ansaldo-Armstrong brand label. After a period of some practical use (as both a land-based and aircraft weapon), deficiencies were soon noticed: the skeletal nature of the magazine allowed all manner of debris into the action and extraction issues from the quick-closing breech were ever present - leading Agnelli to address these issues in subsequent years. For the latter, the chamber was fluted to improve extraction of the bottle-necked cartridges and this seems to have fixed the issue. The feature proved common to many guns since.
On the whole, the Modello 1918 was never a long term answer and its true value never fully realized - relegating it to limited production numbers and a training role within the Italian Army (it was not exported). It soldiered on, more or less, throughout the interwar period before taking its final bow during World War 2 - though by this time it appeared in very limited circulation, outdone by more modern and effective types.