The Davy Crockett Weapon System, a tactical nuclear recoilless gun that fired the M338 nuclear projectile, whose yield was between 10 and 20 tons of TNT (note the tons - not kilotons). The Davy Crockett was operated by three-man crews attached to infantry battalions, and was intended as a defense against Soviet troops and armor in the event of an invasion of West Germany. The limited accuracy of the system meant that the primary effectiveness of the weapon was in its potential for causing lethal dosages of radiation within a quarter mile radius of the blast. 

The Davy Crockett Weapon System, a tactical nuclear recoilless gun that fired the M338 nuclear projectile, whose yield was between 10 and 20 tons of TNT (note the tons - not kilotons). The Davy Crockett was operated by three-man crews attached to infantry battalions, and was intended as a defense against Soviet troops and armor in the event of an invasion of West Germany. The limited accuracy of the system meant that the primary effectiveness of the weapon was in its potential for causing lethal dosages of radiation within a quarter mile radius of the blast.