Specifications for the Jagdpanzer IV originated in 1942 calling for a heavy assault gun with 100 mm armor. It was to replace the Sturmgeschütz in the tank destroyer role as it couldn't be upgunned. Initially it was to be armed with the 7.5 cm Pak 42 L/70 but the Panthers had priority and the 7.5 cm L/48 gun was used.
Guderian was against the project as it took away from the PzKpfw IV tanks. In June 1944 Hitler ordered production of the PzKpfw IV should be abandoned to concentrate on the Jagdpanzer IV.
The crews of the Jagdpanzer IV liked the thick armor and low silhouette.
The chassis chosen to be used was the one used for the PzKpfw IV.
Because of the long barrel gun it caused the Jagdpanzer IV to be nose heavy. The resulted in the front wheels being steel ringed instead of rubber.
Tank Destroyer Armament Performance