Does a paintball gun use any size co2 tank?

Answer 1

size is all personal preference, you can get something as small as a 9oz or up to a 24oz co2 tank, the larger the tank is the more shots you will get off of it but the heavier and larger it will be

Answer 2

Almost all paintball guns fit standard 5, 9 or 20 oz tanks as well as air tanks.