HEAT (High Explosive Anti Tank) ammo has low accuracy and high damage. Popular in the low to medium level games, It has less effectiveness against spaced and reactive armored tanks.
Without gun accuracy upgrades, this round is a scatter-shot at longer range and has the worst accuracy of all ammo types.
As stated before, the HEAT round does higher damage than the other ammo choices, but ONLY against tanks without HEAT countermeasures. Remember which tanks have these, and choosing
the right ammo is super easy. The best chance of using a HEAT round against a high armor tank, is to hit the tracks, or hit the rear armor where it is much weaker.