why

all I use is the base ammo but what purpose does the other ammo types have such as hollow point ?

Do you read up on anything?

What do you think ARMOR PIERCING bullets do? Take a guess.
Hollow Point is for enemies without armor.

The differences between the ammunition types is their effects. Hollow Point ammo is very effective against unarmoured enemies but is weak against armoured enemies. Armour-Piercing is the opposite: you'll deal a lot of damage to highly armoured enemies, but against unarmoured enemies, you're wasting ammo.

If you've played all the DLCs, how haven't you figured this out yet?

LMAO... I mean he doesn't even have to check the wiki for that one. It shows it right there when you LOOK at the different ammo in game!

Buy a few clips of regular, HP and AP ammo for one of your guns, bump the difficulty up to hard and find some mean sons of [censored]es.

You will find the answer to your question...or die trying

how can armour peircing destroy armour but have no effect on a person with out any on ? also between hollow point and base ammo i wasn't seeing any difference other than it harder to aquire a huge stock pile of it

Because AP ammo is more capable at penetrating which is why it's called armor piercing but because of this, an AP round will penetrate soft tissue and pass straight through, creating a cleaner, smaller wound than a regular or HP round. On the other hand, HP rounds are designed to shred soft tissue but aren't very effective against armor.

I don't want to sound patronizing but if you insist on playing on very easy then there is no point to AP or HP rounds. Also it is harder to come by because in the right hands it takes fewer rounds to get the job done so making it as abundant as regular ammo would be unbalanced.

My god, he must be the king of trolls and spammers.