The 20mm M197 is a lightweight three-barrel Gatling aircraft cannon derived from the M61A1 Vulcan family for helicopter, light-aircraft, naval, turret, pod, and pintle installations. General Dynamics Ordnance and Tactical Systems markets the current M-197 and lists it on Marine Corps AH-1J, AH-1T, AH-1W, and AH-1Z aircraft, while FAS, DVIDS, Defense Media Network, and official Navy history sources document M197-equipped AH-1W and MH-60S context across Gulf War, Afghanistan, Iraq, and Operation Inherent Resolve service.
FAS describes the AH-1W as armed with one M197 three-barrel 20 mm nose gun and says 48 Marine AH-1Ws deployed to Southwest Asia during Operation Desert Shield/Desert Storm, where the helicopters destroyed Iraqi tanks, armored vehicles, bunkers, and antiaircraft artillery sites.
A January 2011 DVIDS story from Camp Leatherneck describes AH-1W Super Cobras in Afghanistan providing close air support for coalition and Afghan forces and identifies the nose GPU-A2 system as directing a three-barrel M197 20 mm cannon onto threats.
Defense Media Network describes HMLA-269 AH-1W Super Cobras in Operation Iraqi Freedom combat around Nasiriyah and identifies Maj. Craig Streeter's AH-1W as carrying an M197 20 mm chin-turret cannon.
The official HSC-9 command history says the squadron's 2014 and 2017 USS George H.W. Bush deployments in support of Operation Inherent Resolve saw integration of the M197 20 mm Gatling gun and APKWS on MH-60S Seahawks.
GD-OTS lists the M-197 on Marine Corps AH-1J, AH-1T, AH-1W, and AH-1Z aircraft and also identifies the GPU-2/A gun pod as an M-197 application.
| Carrier | Carrier type | Carriage evidence |
|---|---|---|
 | Attack helicopter | DVIDS identifies the AH-1W Super Cobra's GPU-A2 nose installation in Afghanistan as directing a three-barrel M197 20 mm cannon, and GD-OTS lists the AH-1W among current Marine Corps M-197 applications. Sources: DVIDS 3rd MAW Afghanistan M197, GD-OTS M-197 Gatling Gun |
 | Attack helicopter | GD-OTS lists the AH-1Z as a Marine Corps aircraft armed with the M-197; a Marine Corps public-domain photo separately shows an AH-1Z M197 barrel installation during deployed maintenance. Sources: GD-OTS M-197 Gatling Gun, Marine Corps AH-1Z M197 Photo |
GD-OTS describes the M940 MPT-SD as compatible with 20x102 mm gun systems that include the M197.
| Compatible item | Item type | Compatibility evidence |
|---|---|---|
 | 20x102 mm multipurpose tracer-self-destruct cartridge | The GD-OTS M940 datasheet lists all M197 gun systems among compatible 20x102 mm systems and support equipment. Sources: GD-OTS M940 MPT-SD |
The M197 is the cannon element inside several installations rather than a single aircraft-specific weapon package. In AH-1 service, FAS describes the gun as attached to the A/A49E-7 turret assembly and fed from linked 20 mm ammunition; in the GPU-2/A pod, the same cannon is paired with a self-contained linkless ammunition system.
M197 cannon in an A/A49E-7 turret with 700 rounds of linked M50 or PGU-series electrically primed ammunition.
Self-contained M197 gun pod with 300 linkless rounds and selectable 750 or 1,500 round-per-minute firing rates.
GD-OTS lists the M-197 as adaptable to linked or linkless feed systems for turret, pod, pintle, or internal installations.
FAS states that Marine Corps AH-1Ws armed with an M197 three-barrel 20 mm nose gun deployed to Southwest Asia during Operation Desert Shield and Operation Desert Storm.
Sources: FAS AH-1W Super Cobra
FAS described the AH-1 M197 as a lightweight short-barreled three-barrel Gatling gun and identified the GPU-2/A as a self-contained pod using the same cannon with a 300-round linkless ammunition system.
Sources: FAS M197 Automatic Gun
DVIDS reported AH-1W Super Cobras at Camp Leatherneck and Forward Operating Base Dwyer in Afghanistan and described the GPU-A2 nose installation directing the three-barrel M197 cannon at threats.
Sources: DVIDS 3rd MAW Afghanistan M197
Defense Media Network published a naval-aviation account of Marine AH-1W Super Cobra operations in Iraq that names the M197 20 mm cannon in the aircraft's chin turret.
Sources: Defense Media Network Marine Cobras in Iraq
A Marine Corps photo showed an aviation ordnance technician mounting an M197 20 mm automatic Gatling gun barrel on an AH-1Z Viper aboard USS Anchorage.
Sources: Marine Corps AH-1Z M197 Photo
The HSC-9 command history says the squadron's 2014 and 2017 USS George H.W. Bush deployments in support of Operation Inherent Resolve saw integration of the M197 20 mm Gatling gun and APKWS on MH-60S Seahawks.
Sources: HSC-9 Command History
