Some of the Russian tank designs had some interesting "features". For example, some had a fuel line that ran AROUND the base of the turret. Also, those that had a mechanical loader instead of an actual person loading the shell into the gun, had a round sitting in the open on the loader to speed the reloading process. Additionally, in order to save a little bit of space, they would actually store the ammo in slots inside the fuel tank. Combine all those things, add either a sabot or HEAT round going through the base of a turret, and you've got a giant flaming jack-in-the-box.