I assume probably nothing for both modern tanks and WWII era, but for different reasons.
I think the WWII era tanks basically shot slugs, so hooting a bullet at a much bigger bullet would probably not do much, at the very worst it triggers the firing mechanism and the tank fires normally (but prematurely).
Modern tanks fire much more complex projectiles that contain explosives, so there is the possibility of triggering the detonation mechanism early… But for robust battlefield reasons the detonation mechanism is disabled until after firing. So that is also unlikely.
Now take all of this with a grain of salt, this isn’t the War Thunder forums.
I assume probably nothing for both modern tanks and WWII era, but for different reasons.
I think the WWII era tanks basically shot slugs, so hooting a bullet at a much bigger bullet would probably not do much, at the very worst it triggers the firing mechanism and the tank fires normally (but prematurely).
Modern tanks fire much more complex projectiles that contain explosives, so there is the possibility of triggering the detonation mechanism early… But for robust battlefield reasons the detonation mechanism is disabled until after firing. So that is also unlikely.
Now take all of this with a grain of salt, this isn’t the War Thunder forums.
In ww2 they definitely had differing types of ammunition depending on the application.
You had shells designed to anti armor, anti personnel, even flak rounds.
They def weren’t just shooting slugs.