MGM-51 Shillelagh
| Type: | Cannon-launched guided projectile |
| Guidance: | Line-of-sight command guidance |
| Warhead: | High-explosive anti-tank |
| Range: | 2,200 yards (2,200m) |
| Speed: | 1,050 feet per second (320m/s) |
| Length: | 43 inches (110cm) |
| Diameter: | 6 inches (15cm) |
| Weight: | 60 pounds (27kg) |
| First Firing: | April 1961 |
Shillelagh is a lightweight, surface-to-surface guided missile system designed as main armament for armored combat vehicles, to be used in conjunction with standard unguided projectiles. It was designed to be a direct fire missile launched from a closed breech gun and to be effective against tanks, troops, and field fortifications. Its 152mm gun-launcher could fire either missiles or conventional ammunition and provides high accuracy against moving or stationary targets. The missile was guided to its target by a command system mounted on the launching vehicle and was capable of maneuvering in flight to attack a moving target without ranging or leading by the operator. The initial development contract for the Shillelagh system was awarded in 1959. Basic development testing was conducted at White Sands Missile Range with follow-on testing in Alaska and Panama for cold-weather and tropical-condition testing, respectively.
Shillelagh was intended to be capable of being mounted on a variety of combat vehicles that carried both short and medium range anti-tank missiles, with the Shillelagh serving as the short-range component. Its first and primary application was on the M551 Sheridan, an Army armored reconnaissance and airborne assault vehicle. However, time would introduce cost, development, and production overruns, leading to the M60 main battle tank being the only other system to incorporate the Shillelagh. An attempt to create a helicopter-mounted variant with a gyro-stabilized gunner’s sight was proposed but not pursued, likely due to the BGM-71 TOW successfully filling that role and the role of an infantry heavy anti-tank weapon.
The Shillelagh received two upgrades, designated the MGM-51B and MGM-51C, which were fielded in 1966 and 1968, respectively. Although production of the Shillelagh was stopped by 1971, it and the Sheridan remained in service with the Regular Army and National Guard through the early 1980s, with one Army unit maintaining its compliment of Sheridans until after the First Gulf War. Between 1961 and 1976, a total of 1,574 Shillelagh missiles were launched at White Sands.
