During the vietnam war, the US army had a habit of performing field modifications to many vehicles, one of the most modified was the M113, while initially it only had a single 12.7mm M2HB, however, at some point, a soldier had the idea to replace the machine gun with something that had a little bit more of a brrt, the m134 “minigun”.
History of the M113
The M113 Armored Personnel Carrier (APC) holds a significant place in military history as one of the most widely used and resilient armored vehicles ever developed. Born in the late 1950s from the innovations of Food Machinery Corp. (FMC), it fundamentally changed how mechanized infantry operated, thanks to its groundbreaking lightweight design, amphibious capabilities, and exceptional adaptability.
The U.S. Army needed a new APC capable of keeping pace with modern tanks, being easily airlifted, crossing water barriers, and being straightforward to maintain. FMC answered this call by developing two prototypes: the T117, made of steel, and the T113, which daringly used a light aircraft-grade aluminum alloy. The T113’s superior maneuverability and reduced weight made it the best choice, leading to its official adoption as the M113 in 1960.
Initially, a 209-horsepower Chrysler 75M V-8 gasoline engine powered the M113. However, concerns about gasoline’s flammability in combat quickly prompted a shift to diesel. The M113A1, introduced in 1964, featured a more dependable and safer 215-horsepower Detroit Diesel engine, which rapidly became the new standard. Its distinct boxy shape, complete with a large rear ramp for quick troop deployment, became instantly recognizable. The aluminum armor provided vital protection against small arms fire and artillery fragments, while its tracks allowed for limited amphibious travel, mainly across calm rivers. Typically armed with a single .50 caliber M2 Browning machine gun, its design was flexible enough to accommodate various modifications.
The M113 first saw combat in April 1962, deployed with the Army of the Republic of Vietnam (ARVN) under the Military Assistance Command, Vietnam (MACV) program. It quickly proved invaluable against Viet Cong guerrillas. When substantial numbers of U.S. combat troops arrived in Vietnam in 1965, thousands of M113s, mostly A1 models, became an indispensable asset.
In Vietnam, its ability to navigate dense jungles, traverse rice paddies, and conquer challenging terrain made it crucial for reconnaissance, “search and destroy” missions, and large-scale incursions, making the M113 a valuable asset. Soldiers often improvised modifications, adding extra machine guns and makeshift armor. This led to the widely adopted, though unofficial, M113 Armored Cavalry Assault Vehicle (ACAV) variant, which boasted rotating gun shields and additional machine guns to boost crew protection and offensive power.
Despite its successes, the M113’s vulnerabilities to mines and rocket-propelled grenades (RPGs) became painfully clear. Its lightweight aluminum hull, while agile, wasn’t immune to these significant threats. Consequently, soldiers frequently chose to ride on top of the vehicle, prioritizing better situational awareness and a faster escape in the event of an attack over the limited interior protection against larger explosions.
After the Vietnam War, the M113 predominantly returned to its primary role as an APC. While the U.S. Army began phasing it out of front-line combat in favor of the more heavily armed M2 Bradley Infantry Fighting Vehicle in the 1980s, thousands of M113s diligently continued to serve in countless support roles. They were adapted into armored ambulances, mortar carriers, engineer vehicles, command posts, and many more specialized functions.
The M113’s robust design and cost-effectiveness led to its widespread adoption by over 50 countries globally. It has actively participated in numerous conflicts beyond Vietnam, including the Gulf War and the Iraq War, consistently proving its enduring utility across diverse battlefields. Even today, in the 21st century, various nations continue to upgrade and modernize the M113. For example, companies like Rafael Advanced Defense Systems are transforming older M113s into advanced Infantry Fighting Vehicles (IFVs) with significantly improved firepower, protection, and command-and-control capabilities, ensuring its ongoing relevance in modern warfare.
While its time as a primary front-line personnel carrier might be fading in some advanced militaries, the M113’s remarkable legacy as a versatile, reliable, and adaptable military workhorse is firmly etched in history.
VEHICLE SPECIFIC INFO:
While concrete info on this is limited due to its nature of being an unauthorized field modification, we do know the info about the different components and how they interacted.
The M113 (Hull)
Top speed: 40 mph
Top speed in water: 3.5 mph
Crew: 4
Guns: M134D (7.62) (hatch mounted) ammo: 1500 rd belt fed from a box magazine
Armor:
(Rolled 5083/5086 H32 aircraft grade aluminum armor)
Front: 38mm
Sides: 44-38mm
Rear: 38mm
Top: 38mm
Bottom: 28mm
Gun shield: 12.7mm
The M134 (Weaponry)
The M134 Minigun, a formidable Gatling-style rotary machine gun, stands as one of the most iconic and devastating rapid-fire weapons ever developed. Conceived in the early 1960s by General Electric, its design was a direct response to the need for suppressive firepower from aircraft and vehicles during the Vietnam War. Drawing inspiration from the multi-barrel, hand-cranked Gatling guns of the 19th century, the M134 modernized this concept by incorporating external electric power to drive its six rotating barrels, allowing for an incredibly high rate of fire. Chambered in 7.62x51mm NATO, its ability to unleash thousands of rounds per minute (typically between 2,000 and 6,000 RPM, though capable of more) quickly made it a preferred weapon for close air support, suppressing enemy positions, and engaging fast-moving targets. Its characteristic “brrrrrrt” sound became known as a sign of overwhelming firepower, and fundamentally changed the future of warfare.
Primarily deployed on helicopters like the UH-1 “Huey” and AH-1 Cobra gunships, the M134 Minigun provided an unparalleled volume of fire for suppressing enemy infantry and light vehicles. Its design, while incredibly effective, necessitated an external power source to operate the barrels and feed mechanism, along with a significant ammunition supply system, making it less suitable for portable infantry use. Despite its age, the M134 and its numerous variants and derivatives continue to see active service globally. Its legacy endures in modern military applications, from naval vessels and ground vehicles to specialized aircraft, cementing its reputation as a benchmark for rapid, sustained suppressive fire and maintaining its status as a visually and audibly impressive weapon system.
Fire rate: 3000 RPM
- Yes
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Sources
M113 (Armored Personnel Carrier) - The Army Historical Foundation
APC M113 (multiple sources listed here)
https://www.military-references.com/wp-content/uploads/books/tracked_vehicles/usa/m113/M113A1_Operator_s_Manual_TM-9-2300-257-10_1978.pdf
T113E1 and E2 (Development of the M113) - Tank Encyclopedia
M134D – Standard 7.62 x 51mm – Dillon Aero