For combat trials the two prototypes were assigned to Panzerjäger Abteilung ("Anti-tank Battalion") 521 during the invasion of the Soviet Union. One accidentally caught fire and was completely destroyed by the detonation of its ammunition, but the other fought successfully until the end of 1941. It was rebuilt by Krupp during the first half of 1942 and returned to the 521st in time to participate in Case Blue, the 1942 summer offensive in Russia.