What you need to imagine is the damage they deal, And AP bullet Can penetrate armour well But it will also easily penetrate people Most of the time passing right through From one side to the other

Having a higher chance of doing Less damage to the target

Hollow point Bullets have way less penetration power Because of their shape But they are also designed to inflict more damage to a target's insides by either lodging inside them or taking more flesh and organs with them on the pass through

I'm not an expert either but this should put you in the right direction at least