Scotti Model X
Isotta Fraschini S.p.A. · Machine Gun · Out Of Production · 1932
Also known as: Scotti 7.7mm, Scotti-Isotta Fraschini Mod. 1933, Mitragliatrice Scotti
Overview
The Scotti Model X is an Italian aircraft machine gun chambered in 7.7x56mmR (7.7mm Breda, the Italian-produced equivalent of the .303 British cartridge). Designed by Alfredo Scotti of Brescia and manufactured by Isotta Fraschini, it uses a gas-unlocked, rotating-bolt-head retarded-blowback action firing from an open bolt with belt feed at roughly 850-880 rounds per minute. Weighing about 11.5 kg and 1,120 mm long, it was lighter than the rival Breda-SAFAT and was adopted by the Regia Aeronautica in the early 1930s, serving on flexible defensive mounts in Italian bombers and reconnaissance aircraft such as the CANT Z.1007 throughout the Second World War. Because it fired from an open bolt it could not be synchronised to fire through a propeller, restricting it to free-mounted defensive emplacements where it remained second to the more widely issued Breda-SAFAT.
Specifications
| Weight (empty) | 11500 g (405.7 oz) |
| Overall Length | 1120 mm (44.09") |
| Barrel Length | 700 mm (27.56") |
| Action Type | Gas Operated Rotating Bolt |
| Firing Mechanism | Open Bolt |
| Trigger Type | Automatic Only |
| Magazine Type | Belt |
| Muzzle Velocity | 740 m/s (2428 fps) |
| Muzzle Energy | 3120 J (2301 ft·lbf) |
| Effective Range | 1000 m (1094 yd) |
| Maximum Range | 3500 m (3828 yd) |
| Rate of Fire | 880 rpm |
| Barrel Rifling | Right Hand |
| Frame Material | Steel |
| Barrel Material | Steel |
| Finish | Blued |
Calibers
- .303 British · primary — also known as 7.7mm Breda, 7.7x56mmR, 7.7mm Italian, .303 Mk VII
Features
- Firing modes: Full Automatic
- Feed systems: Belt
- Features: Gas Operated Action, Rotating Bolt Head, Belt Feed, Flexible Mount, Air Cooled Barrel
Variants
- Scotti 12.7mm — Heavy Caliber
Service history
Operators
- Regia Aeronautica · adopted 1933 · as Mitragliatrice Scotti 7.7mm
Conflicts
- Second Italo-Ethiopian War (1935-1937)
- Spanish Civil War (1936-1939)
- World War II (1940-1943)
Production
Production years: 1932-1943
Produced in limited numbers; the Breda-SAFAT was the dominant Italian aircraft machine gun, with the Scotti issued only to a limited degree.
Origin
Country of origin: Italy
Designer: Alfredo Scotti
Discontinued: 1943
Notes
The 'X' designation denotes Anno X of the Fascist calendar (1932). Mechanically the gun is a gas-unlocked retarded-blowback: a gas piston rotates the two-lug bolt head to unlock the breech while residual case pressure drives extraction, so it is often described loosely as 'gas-operated' though it is not a conventional locked-breech gas system. The same Scotti action was scaled up into a 12.7mm heavy aircraft machine gun (mounted, for example, in the Caproni-Lanciani Delta turret of the CANT Z.1007) and into the Scotti-Isotta Fraschini 20mm autocannon; Oerlikon held the export licence from 1932. NOTE: do not confuse this aircraft machine gun with the separate 6.5mm Carcano 'Scotti Model X' semi-automatic infantry rifle (~250 built, never adopted) that shares the same Anno X designation.
Background
Alfredo Scotti, working from a small design office in Brescia, sold his gas-unlocked-blowback patents to firms across Europe rather than mass-producing weapons himself; his action ultimately found its widest fame not as a machine gun but as the heart of the Scotti-Isotta Fraschini 20mm anti-aircraft cannon.