Don't know if anyone might be interested but if you're considering buying a compressed air tank and aren't sure what size/pressure you need this is a handy tool.
http://www.scubatoys.com/paintball/paintballshots.aspObvously, that varies with the gun, and the tank, and the pressure you are dealing with. This handy calculator will give you a good ball park of what you can expect - depending on your gun. We did some extensive testing with multiple guns to construct this calculator. Using a digital pressure gauge, we determined how many shots we could get with a fixed volume and pressure, then we adjust for different size bottles and pressures. One of the best we tested was a Timmy, and while one of our favorite guns, the Shocker turned out to be the biggest gas pig. The Tippmann A5 ended up dead middle on our tests - even with the air feed hopper. Note that your results may vary, as what chrono speed your gun is set for, how dry or oiled your o-rings are, etc will cause some variations to these numbers.
It DOES require that you have a general idea of whether you have an efficient marker or not, other than that the math is all taken care of for you. I don't know how accurate it is, I got 1900 shots out of my TM-7 with a 110ci tank filled to 3,500psi and to get close to that with the calculator (1732 shots) I had to classify it as "
Very Efficient".
Anyway, it's a good tool to use as a guideline.