Hispano Suiza HS-404

In 1933, Marc Birkigt, the chief engineer of Hispano Suiza company, began the design of a new 20mm gun that was not based on the loading system of the previous Oerlikon guns, built under license by Hispano Suiza until then. The new gun’s loading mechanism, allowed a faster ejection and loading of the projectile, improving the firing rate in 200 rounds more per minute compared to the previous models. The gun was designated Hispano Suiza HS-404 or Type 404 and began to be built in 1938. This gun was suitable to be mounted on vehicles or mobile carriages due to its light weight and could be deployed quickly practically anywhere. There was a variant produced to be assembled in aircrafts that had a lot of success and was manufactured under license by the British as Hispano Mk.I, Mk.II and Mk.V guns and by the Americans under designations M1, M2 and M3 / M24 guns. Production ceased in the 1960s after tens of thousands HS-404s produced.

Hispano Suiza HS-404 gallery and more info


Información adicional

Ficha Completa
Country of origin



Hispano Suiza


Anti-aircraft gun

Entered service


Combat weight

43 kg (gun barrel)

Dimensions (length x width x height)

2.52 meters (gun length)


1 x 20/85.5mm gun

Rate of fire, (maximum)

700 rounds per minute

Shell weight

From 0.13 to 0.17 kg

Shell range

2,000 meters ceiling

Muzzle velocity

880 m/s