Oerlikon 20 mm cannon

Oerlikon 20 mm cannon
Oerlikon 20 mm cannon in French service
Type	Autocannon
Place of origin	Switzerland
Service history
In service	1937–present
Used by	Various
Wars	World War II, various
Production history
Designer	Reinhold Becker
Designed	1935
Manufacturer	Oerlikon
Produced	1937–
No. built	124,734[1]
Variants	Oerlikon FF MG FF cannon
Specifications
Mass	L70 Total gun barrel weight: 68.04 kilograms (150.0 lb) Minus breech mechanism: 20.865 kg (46.00 lb) L85 Empty: 92.0 kilograms (202.8 lb) Loaded with 200 rounds: 182.0 kg (401.2 lb)
Length	L70 Overall: 2,210 mm (87 in) Barrel length: 1,400 mm (55 in) L85 Overall: n/a Barrel length: 1,700 mm (67 in)
Shell	L70: 20×110mmRB L85: 20×128mm
Shell weight	HE: 123 g (4.3 oz) HE/T: 116 g (4.1 oz)
Caliber	20 mm (0.787inch)
Barrels	Single barrel (progressive RH parabolic twist, 9 grooves)
Action	API blowback
Elevation	Manual, -15°/+90°
Traverse	Manual, full 360°
Rate of fire	L70: Cyclic: 450 rounds per minute Practical: 250-320 rounds per minute L85: Cyclic: 900 to 1,000 rounds per minute
Muzzle velocity	L70: 820 m/s (2,700 ft/s) L85: 1,050 m/s (3,400 ft/s)
Effective firing range	Against low-flying aircraft (HE round) L70: 914 m (1,000 yd) L85: 1,500 m (1,600 yd)
Maximum firing range	HE round at 45° L70: 4,389 m (4,800 yd) L85: 6,800 m (7,400 yd)
Feed system	Cylindrical magazine holding 60 rounds, Later adjusted to be a belt fed gun

The Oerlikon 20 mm cannon is a series of autocannons based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II. Many versions of the cannon are still used.^[2][3]