m113a1/as4/g3dk/g4dk/m577 (cp) (estimated)

The M113 is a fully tracked armored personnel carrier (APC) that was developed and produced by the FMC Corporation. The M113 was sent to United States Army Europe in 1961 to replace the mechanized infantry's M59 APCs. The M113 was first used in combat in April 1962 after the United States provided the South Vietnamese army (ARVN) with heavy weaponry such as the M113, under the Military Assistance Command, Vietnam (MACV) program. Eventually, the M113 was the most widely used armored vehicle of the U.S. Army in the Vietnam War and was used to break through heavy thickets in the midst of the jungle to attack and overrun enemy positions. It was largely known as an "APC" or an "ACAV" (armored cavalry assault vehicle) by the allied forces. The M113 was the first aluminum hull combat vehicle to be put into mass production.

Developed by the FMC Corporation to provide a highly mobile, air-transportable infantry transport, the diesel-powered M113A1 variant entered service in 1964 to improve operational range and safety over the original gasoline-powered model. The platform saw extensive combat during the Vietnam War and the Gulf War, while international operators adapted the chassis into specialized local variants, such as Australia's upgraded AS4 and Denmark's G3DK/G4DK configurations. The M577 command post version similarly became a staple of tactical operations globally, coordinating forces from secure mobile hubs. Although increasingly replaced by modern platforms like the Armored Multi-Purpose Vehicle (AMPV), the M113 family remains in active service with dozens of militaries worldwide, securing its legacy as one of history's most prolific armored vehicles.