The Soviets made some pretty good tanks during WWII. This was causing the Germans some issues. They had their reliable Pak 40 gun, but it wasn’t easy to move the thing around. And the original Tank Destroyers that were made had exposed crew quarters, so they could be taken out with small arms fire. The Pak 40 auf RSO compensated for that with an armored crew compartment, even though it made the whole thing rather slow. Now, you can bring it to your Bolt Action battlefield and take out those annoying T-34s.
From the post:
German ingenuity and efficiency have bought a new weapon to the Bolt Action battlefields – the new Pak 40 auf RSO… available in three different options. Crew with either Heer, Heer in Winter equipment, or Waffen-SS uniforms.
In 1943, some 60 Raupenschlepper Ost (RSOs), were modified by mounting a Pak 40 anti-tank gun and some light armour plates for the protection of the crew from small arms fire.
The resulting tank destroyer, regardless of the fact that it was quite slow due to the weight of these additions, was rushed into use to face the growing threat of the Soviet armoured divisions.