The StuG IV was first considered as an alternative to Panzer III based vehicles in 1943 when trials were carried out to test whether the superstructure of the StuG III could be fitted on the hull of the Panzer IV. These early tests proved fortuitous when the StuG III factory at Alkett was heavily damaged in bombing and production stopped. 

As an alternative, StuG IV production was started at Krupp in December 1943 and by January 1944 all Panzer IV production at Krupp had switched to the StuG IV.

The StuG IV was soon being issued to the independent Sturmgeschütz brigades of the Wehrmacht, Panzerjäger units, and Panzer units. It was used as both an assault gun in support of the infantry as well as a tank hunter, proving equally deadly in both roles. 

It has 80mm of front armour, 30mm of side and 11mm on top. Armed with the 7.5cm StuK40 and a MG34. 

[High Resolution]

Sturmgeschütz IV, 7.5cm StuK L/48. Sd Kfz 167 [HR]

While the Panzer 38(t) had largely become obsolete as a tank in early 1942, it was still an excellent platform for adaptation into a tank destroyer, among other roles. Since the Soviet 76.2 mm field gun was captured in large quantities, the decision was made to mate this gun to the Panzer 38(t).

To do so, the turret and upper superstructure of the Panzer 38 were removed and a new superstructure was bolted on to the chassis. The upper structure mounted the gun and an extended gun shield, giving very limited protection for the commander and the loader. Armour protection overall ranged from 10 to 50 mm. The gun, commander and loader were located on top of the engine deck. It had higher silhouette than Panzer 38, which made it more vulnerable to enemy fire.

The now-called 7.62 cm PaK 36(r) was rechambered to be able to use standard German 75 mm ammunition, of which 30 rounds could be carried inside the vehicle. Apart from the main gun, there was a 7.92 mm machine gun mounted in the hull.

This tank destroyer was put into production as the Panzerjäger 38(t) für 7.62 cm PaK 36(r), Sd.Kfz. 139. A total of 363 of this Marder III variant were built from April 1942 to 1943. [High Resolution]

Marder III, Sd.Kfz. 139 [HR]

Sturmgeschutz III ausf. B of Sonderverband 288. Most historians claim that this is a ausf. D, but the lower hull is fitted with the headlamp covers found on the ausf. A and B versions.