it's not just the caliber of the ammo, it's also the velocity. I'm certainly not an expert, but I did my military service in a base used for tank training. Back

it's not just the caliber of the ammo, it's also the velocity. I'm certainly not an expert, but I did my military service in a base used for tank training. Back then, it was already a done deal : no armor could resist the amount of energy released by anti-tank ordnance, in particular kinetic penetrators. I've seen up close old tanks which were used for training. On the entry side of the impact you have a perfectly cut circular hole a few cm in diameter, with slits all around like petal flowers. On the exit side you have a big open tear. In between, there was a jet stream of molten metal. Bottom line : a spotted tank is a dead tank. That was a fairly long time ago, but unless armor has made huge progress since then, producing something hard enough to deflect this kind of force and yet light enough that the tank can move, I'd still bet on an A10 against anything rolling on the ground.