You find ammo all around the wasteland. Different types of ammo is
used in different types of guns. There are usually 3 different types
of ammo: Jacketed Hollow Point (JHP), Armour piercing (AP), and Full
Metal Jacket (FMJ). JHP ammo usually does double damage but is bad
against armour, AP does half damage but is good against armour, and
FMJ is in between. That is how the theory is supposed to be anyway.
But because AP ammo does half damage, and JHP does double damage,
that makes JHP 4 times stronger than AP. Even though AP is good
against armour, it isn't that good, and JHP will still do more damage
than AP. FMJ is pretty good all round