Key Points and Summary – Long overshadowed by the Bradley, the M113 remains one of the U.S. Army’s most prolific and adaptable armored personnel carriers.
-Entering service in 1960, the lightweight, aluminum-hulled APC carried 11–15 troops and proved its worth in Vietnam—where field mods birthed the ACAV, adding shields, extra guns, and mine protection.
-Variants like the M163 Vulcan excelled against massed infantry, and the type later served from Panama and Desert Storm to Iraq and beyond.
-Though replaced on the U.S. front line, thousands continue in support roles—ambulance, command, engineer, and mortar carrier—and over 50 nations still operate M113s. A true workhorse that refuses to retire.
M113 Explainer: The US Army’s Forgotten APC
When one thinks of the United States Army and armored personnel carriers (APCs), chances are they think of the Bradley Fighting Vehicle, and understandably so, seeing how it has been in service since 1981 and first established its reputation for combat effectiveness during the 1991 Persian Gulf War, AKA Operation Desert Storm.
Troopers assigned to 1st Battalion, 12th Cavalry Regiment, 3rd Armored Brigade Combat Team, 1st Cavalry Division, engage an opposing force during the testing of the newest version of the Bradley Fighting Vehicle, Fort Hood, Texas, Oct. 24, 2020. Operational testing with the U.S. Army Operational Test Command (OTC), places First Team Troopers in a series of maneuvers and engagements where OTC can properly test the new vehicles. (U.S. Army photo by Sgt. Calab Franklin, 3ABCT, 1CD, PA NCOIC)
Troopers with 3rd Armored Brigade Combat Team, 1st Cavalry Division firing the 25mm canon on a Bradley fighting vehicle in order to zero the vehicles weapons systems at a range in Poland. Ranges such as these familiarize troopers with the vehicles systems in order to ensure combat readiness.
However, what tends to get lost in the shuffle is another US Army APC that has provided faithful service even longer than the Bradley (with a 21-year head start, no less) and continues to quietly serve, even as the Bradley continues to grab more headlines.
National Security Journal now gives the workhorse known as the M113 its long-overdue and well-earned place in the spotlight.
M113 Initial History
Built by the FMC Corporation (headquartered in Philadelphia, Pennsylvania, and now known mainly as an agricultural sciences company), the M113, for whatever reason, didn’t receive a catchy official nickname like the Bradley did (named for Gen. Omar Nelson Bradley, former General of the Army and first Chairman of the Joint Chiefs of Staff).
According to TankNutDave.com, FMC was awarded the contract in January 1956 in order to develop an air-deployable vehicle that was amphibious and had good mobility whilst still able to withstand 7.62mm fire (ability to withstand impacts from heavier ordnance would have obviously required thicker armor that have compromised lightness and mobility).
FMC developed two prototypes: the T117, made of steel, and the T113, made of aluminum.
The latter won out, and it entered into the complete production phase in 1960, with the placing of an initial order for 900 vehicles. Approximately 76,000 specimens were produced between 1960 and 2007.
M113 Technical Specifications and Vital Stats
-Crew: 2 (commander and driver) plus 11-15 troops as passengers
-Length: 15 feet 11.5 inches
-Width: 8 feet 9.7 inches
-Height: 8 feet 2 inches
-Mass: 13.8 short tons
-Powerplant: 6-cylinder Detroit Diesel 6V53T engine generating 275 hp (205 kW)
-Maximum Speed: 42 mph (paved roads); 3.6 mph (“swimming” mode)
-Operational Range: 300 miles
-Armament: 1 x Browning M2 “Ma Deuce” .50 caliber machine gun (standard; see next section for additional improvised weapons systems).
Operational Performance/Combat History
As was the case with the M551 Sheridan light tank, the M113 APC was first “blooded” in combat during the Vietnam War, serving with both U.S. forces and their ARVN (Army of the Republic of Vietnam, i.e., the South Vietnamese Army) allies.
According to Matthew J. Seelinger of the Army Historical Foundation, “At first, the APCs proved effective against Viet Cong (VC) guerrillas, who had few heavy weapons to counter the M113s. Soon, however, a number of weaknesses in the M113 emerged. In particular, the position of the machine gun left the gunner exposed.
During the Battle of Ap Bac on 2 January 1963, ARVN forces lost several M113 gunners to VC guerrillas, who concentrated their fire against the vulnerable M113 crewmen.
As a result, ARVN soldiers and their American advisors came up with a number of unauthorized field modifications, adding more machine guns and recoilless rifles to the M113’s standard armament, and developing shields to protect the gunners.”
The ARVN also added additional floor armor to protect the vehicle from land mines, a favorite weapon of the VC. These up-gunned and up-armored models became known as Armored Cavalry Assault Vehicles, or ACAVs.
Soon enough, the US forces would take a hint from their South Vietnamese counterparts and follow suit, performing their own ACAV modifications, tacking on weapons such as M60 7.62mm machine guns, flamethrowers, and, in the case of the M163 variant, an M61 Vulcan 20mm Gatling gun (which had initially been designed as an air defense weapon!
These customizations would prove fortuitous, with the M163 proving extremely effective against ground targets, especially massed enemy infantry.
Other branches of the US armed forces also started adopting the M113; small numbers were used by the US Air Force Security Police to protect USAF bases in Vietnam.
All in all, to cite Mr. Seelinger again, “The M113 ACAVs and other variants proved successful in the jungles and rice paddies of Vietnam.”
The M113 would go on to serve in the following wars and with the following entities:
-1973 Yom Kippur War – Israeli Defence Forces
–Operation Peace for the Galilee (1982 Lebanon War) – Israeli Defence Forces
-1982 Lebanon War – Israeli Defence Forces
-1989 Invasion of Panama (Operation Just Cause) – US forces
-1991 Gulf War (Operation Desert Storm) – U.S. forces and Arab Coalition allies
-2003 Iraq War (Operation Iraqi Freedom) – U.S. forces
-2006 Lebanon War – Israeli Defence Forces
Where Are They Now?
Amazingly, the M113 remains in service with a whopping 53 countries, including Iraq, the Philippines, Pakistan, Ukraine, and Uruguay.
In US Army service, the vehicle has long since been supplanted by the Bradley for frontline combat missions due to the newer APC’s superior armament and armor.
However, large numbers of M113s continue to serve in unsung but still vital support roles, such as armored ambulances, mortar carriers, engineer vehicles, and command vehicles.
In the 2025 edition of its open-source publication titled The Military Balance, the International Institute for Strategic Studies (IISS) estimates that the Army has 4,200 M113A2/A3 in active service, with an additional 8,000 in storage.
After 65 years, it appears as though the M113 isn’t going anywhere anytime soon.
About the Author: Christian D. Orr, Defense Expert
Christian D. Orr is a Senior Defense Editor. He is a former Air Force Security Forces officer, Federal law enforcement officer, and private military contractor (with assignments worked in Iraq, the United Arab Emirates, Kosovo, Japan, Germany, and the Pentagon). Chris holds a B.A. in International Relations from the University of Southern California (USC) and an M.A. in Intelligence Studies (concentration in Terrorism Studies) from American Military University (AMU). He is also the author of the newly published book “Five Decades of a Fabulous Firearm: Celebrating the 50th Anniversary of the Beretta 92 Pistol Series.”
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