AP vs Standard rounds

[Nazsteph]

If someone could point me in the direction to find out what is the difference between these two types of ammo it would be very appreciated. I usually load up a favorite with all AP rounds thinking that they will pierce the hard outer shell and get to the squishy stuff in the center. But, I have not found either type to have a significant improvement over the other in killing the enemy. If someone could give me an idea of what type they use for which targets, I would be very thankfull.

Nazsteph - At least my knife dosnt require ammo.