

If the weapon system is firing on a high trajectory (firing without seeing the target) rather than a flat trajectory, the vehicle would be a self-propelled howitzer rather than a tank. An armoured personnel carrier has no major caliber weapon, and a tank destroyer hunter has little or no armor. A non-track armored vehicle carrying heavy weaponry firing flat trajectory is a mobile gun system (MGS). They are a specific combination of tracks, armor, turret, and weapon without any one of these four components, the vehicle is no longer a tank. Tanks are tracked armored vehicles that have a rotating turret mounting a heavy weapon firing on a flat trajectory (firing with line of sight to the target).
