SIA Mod. 1918

Societa Italiana Aviazione (SIA) · Machine Gun · Out Of Production · 1918

Also known as: Mitragliatrice Leggera SIA Modello 1918, SIA Model 1918, SIA M1918

Overview

The SIA Mod. 1918 was an Italian light machine gun produced by Societa Italiana Aviazione, a FIAT subsidiary, originally conceived as an aircraft gun and then repurposed for infantry use. It fired the 6.5x52mm Carcano cartridge from a top-mounted 30-round detachable box magazine via a friction-retarded (delayed) blowback action operating in full-automatic only. Its chrome-nickel steel barrel was cooled by a distinctive radiator of 52 circular aluminum discs. Rushed into service late in WWI, it suffered chronic extraction and reliability problems, and was withdrawn by the mid-1920s.

Specifications

Weight (empty)10200 g (359.8 oz)
Overall Length1113 mm (43.82")
Barrel Length635 mm (25.00")
Action TypeBlowback
Magazine Capacity30 rounds
Magazine TypeDetachable Box
Muzzle Velocity680 m/s (2231 fps)
Muzzle Energy2415 J (1781 ft·lbf)
Effective Range800 m (875 yd)
Maximum Range3000 m (3281 yd)
Rate of Fire500 rpm
Barrel RiflingRight Hand
Frame MaterialSteel
Barrel MaterialSteel

Calibers

Features

Service history

Operators

Conflicts

Production

Production years: 1918-1923

Planned target of ~18,000 units; actual output limited and not exported

Origin

Country of origin: Italy

Designer: Giovanni Agnelli

Discontinued: 1923

Notes

Caliber is rimless (some references mislabel it rimmed). Capacity of 30 rounds is confirmed; weight of ~10.2 kg is the cited spec, though one source gives ~16 kg. Muzzle energy derived from standard 6.5x52mm data. A fluted chamber was added to ease extraction problems.

Background

The SIA Mod. 1918's retarded blowback action closed too quickly on the bottlenecked Carcano case, causing persistent extraction failures and case ruptures, while its open skeletal magazine let dirt straight into the action. A 1922 Italian army report concluded the gun did not take long to manifest the defects of its hasty design, and the aluminum-disc radiator was essentially a band-aid to keep the overheating barrel from fracturing.