How much use do u get out of a 10lb tank?

That all depends on how you use it. Keep in mind that a 10lb CO2 tank cost around $23 to fill each time it's empty and not many places will refill your own bottle while you wait.

That all depends on how you use it. Keep in mind that a 10lb CO2 tank cost around $23 to fill each time it's empty and not many places will refill your own bottle while you wait.
Airgas will exchange your tank. So, if your not worried about how your tank looks/personal touches....it works just fine.
But, I didnt know about paintball shops....thats good to know.
My tank is just compressed air not CO2, but paintball people will fill CO2 stuff as well, thats what most people run in there guns anyways cuz the airtank setup is so much more expensive up front, and 20oz of compressed air is good for like 500 shots, where C02 is good for 1500 or so. But I got a sweet scuba fo free with the fill setup on top which is also not super cheap, and its got a quick disconnect fitting. Ive got some aluminum brackets for holding 6" PVC pipe onto a roof rack as a storage compartment, which are going to work perfect to hold the scuba securly in the back of the blazerI know its not good for tools and such, but if its enough to get air in a tire to get it out of the dunes or something thats better than nothing right??
There's a paintball place in Gilroy that I use to fill mine. There's also a place in Santa Clara area called Beverage Service that fills while you wait.
-Brian
Was actually wondering about that beverage place. It's like half a mile from my work I pass it every now and then.