Bullet weights are measured, Imperial, in "grains" Metric system in grams. Imperial, bullet speeds ("muzzle velocity") are in feet per second; meters/second otherwise.
A hard, cohesive, pointy bullet of a given weight and speed, spinning in order to keep it going straight, will damage its target by making a bullet-size hole in it. A softer hollow-point bullet of the same size and speed will expand and make a bigger mess. Specialty bullets made for damaging meat will do a lot more damage, at the same weight and speed.
There are commercial gun magazines--that is to say, paper publications--that would give you more data, to the point of ennui or horror. A good starting point would be
NRA.org; if you've time enough, you could get more figures than you'll need for your science project.
