AP Rounds

[Gunslanger]

OK, so how do AP rounds actually work VS regular rounds? i know they are more effective VS MAXes. i know they do a signifigant amount less damage to personel than regular rounds(i mean on an individual unarmored). are AP rounds better agains spitfires and other deployables? what about vehicles like mossies? they have virtually no armor, are AP rounds still better? as much detail here as possible please. would be some good info thanx