Rocking, lurching movements of a tank over rough ground are simulated by a stationary gun mount devised by a Fort Knox officer for use in training gtinners to fire accurately from moving tanks. Mounted on a post through a universal joint, a wooden 37-millimeter tank gun is aimed by means of a regulation gun sight. In order to check the gunner's accuracy, a repeating BB gun is at- tached to the dummy. While the gunner attempts to hold the gun on a fixed target as he would from within a tank, another person wobbles the platform vigorously.