When spawning a tank such as the LandKruezer, Exoniphic MK1 and Leopard they will have 10 Armor piercing shots, smaller tank vehicles like the Panzer 3 and Trelet Barshky 4x4 will have 8 shots.
The explosive shell power-up will give 5 shots and should be fixed so it cannot be picked up by non tank vehicles, if you pick up another explosive shell power up those shells will also be added to your ammo, if you pick up an explosive shell power-up before using all AP shots you will have to fire the rest of the AP shots before you can fire the explosive shells.
For juggernaut all tanks should still have the shredder for better protection as the gun alone isn’t that effective against cars that are right next to it.
No it wouldn’t, the tanks are already next to useless with the single shot and it’s very diffcult hitting fast cars, as for juggernaut the gun is helpful having unlimited ammo but is no good when getting swarmed by cars, the shredder would be much better to have.