A full size turret with a 120 mm gun is on display at the Armed Forces History Museum in Largo, FL.

Information on the M103 Tank


The M103 Heavy Tank was developed post WWII and put into service beginning in 1957.  This tank was the largest and most armed tank that had ever been developed for the US Army and USMC.  This huge piece was developed during the Cold War Era to meet the challenges of the heavy tanks developed by the USSR.

The USMC acquired 220 of these tanks for supporting their infantry units, while the US Army acquired 80 of the tanks.  A total of 300 were built.  None of these tanks were ever used in combat.

The extra-large 120mm cannon required that the turret be larger than the M48 or M60 tanks to accommodate two loaders, plus the gunner and commander.  The gun could be elevated between 15 ᴼ+ to -8ᴼ degrees.

Many additional modifications were made and shared with the M47 and M48 Patton tanks and the M60, which were all medium tanks with 90 mm guns.  Two additional variations that were developed included the M103A1 in 1959 and the M103A2 in 1964.  The M103 was very underpowered and the transmissions were fragile, thus this tank never had enough power to operate properly.  The United States withdrew this tank from service sometime in 1974.

Quite a few of the M103s can still be found on some US military bases, while others can be viewed at various museums throughout the United States.


Crew:  5 (Commander, driver, gunner, 2 loaders)
Tank Armor:  7.2” – 7.34”
Main Armament for the M103:  120mm – M58
Rounds:  34
Secondary Armament for the M102:  2 - .30 cal – M1919A4E1- machine guns
1 - .50 cal – M2AA – machine guns

Tank Engine:

Continental AV1790, 12 cylinder – air cooled (M103A2)
Continental – AVDS – 1790-2, V-12 air cooled, twin turbo charged  diesels
810 hp and 750 hp

Operation Range:

80 Miles for the M103
295 miles for the M103A2
21 mph (M103)
23 mph (M103A2)