For the bullets themselves, in addition to the diameter and length you've got mass, material and shape (round nose, hollow point, ballistic tipped, etc.). For

For the bullets themselves, in addition to the diameter and length you've got mass, material and shape (round nose, hollow point, ballistic tipped, etc.). For the cartridge as a whole you're also going to be concerned with powder capacity, shape (necked?, rimmed?), and to a lesser extent material. These are just a few examples and all are significant.