20mm M197
Overview
20mm M197
20mm M197 three barrel autocannon seen on a Japanese AH-1S attack helicopter. Note that the cowling is removed for maintainance.
Source: HUnini -
© CC BY-SA 4.0
Origin
United States
Type
Autocannon
Entered service
1967
Status
In service
Development
Mid 1960's
Developer
United States
Production
Mid 1960's - Present
Producer
United States
-
General Electric (up to 1993)
United States - General Dynamics Ordnance and Tactical Systems (present day)
Japan - Sumitomo Heavy Industries
United States - General Dynamics Ordnance and Tactical Systems (present day)
Japan - Sumitomo Heavy Industries
Number produced
At least thousands
Designations
XM197
Details
Facts
20mm M197
General
Origin
United States
Type
Autocannon
Caliber
Caliber
20x102mm
Feed system
Belf-fed or linkless feed system
Barrel length
1.524 mm
Rifling
9 grooves, progressive right hand twist
Muzzle velocity
1.030 m/s
Operation
Action
Three barrel Gatling type
Rate of fire
Up to 1.500 rpm
620 to 680 rpm as installed on AH-1 Cobra
Recoil force
5.8 kN average
Power source
External hydraulic, electric or pneumatic
Dimensions
Weight
60 kg
Length
1.828 mm
Media
20mm M197
20mm M197 three barrel autocannon seen on a US Marine Corps AH-1Z Viper attack helicopter
Source: US Marine Corps
Copyright: Public domain
20mm M197
20mm XM197 three barrel autocannon in a flexible door mount on an AU-23A Peacemaker counter-insurgency aircraft used during the Vietnam war.
Source: San Diego Air and Space Museum Archive
Copyright: Copyright lies with original owner
Related articles
20mm M61 Vulcan
The design of the M197 is derived from the six barrel M61 Vulcan.
20mm M195
Earlier attempt at converting the M61 Vulcan for helicopter use. Predecessor to the M197 that reduced weight with shorter barrels, while retaining all six barrels.