The appearance of the T-34 in 1941 caused a crisis for German antitank forces. Existing antitank guns were nearly impotent against the new Russian tank, while antiaircraft and artillery pieces, though successful when pressed into action, were insufficiently mobile to accompany mechanized forces. The German Army Ordnance Office, the Heereswaffenamt, was responsible for development of new weapons and would be responsible for countering the threat of Russian armor. The Heereswaffenamt would need to not only counter the T-34, but also do so in an environment of shifting political relationships and with an increasingly stressed industrial system. This paper discusses the development of the Jagdpanzer IV - “Guderian’s Duck.”