Magicwolf,
As I have said in my past posts. Find yourself a used 80 cu. ft. scuba tank with a Kvalve. They go for about $120 to $150 around here. Get an aluminum one rather than steel to help keep the weight down and be done with it.
For the size of the gun you are looking at with the air resevior it has you need volume, think CUBIC FEET not inches. Get on the net, check out craigs list, ebay, call the local dive shop and talk to someone and tell them what you want to do.
Carbon fiber tanks are nice AND EXPENSIVE. You do not need to start out with a carbon fiber tank. As I suggested earlier in the this and another post buy used and if you can get it from a local dive shop. They will walk you thru what to watch for. Then get your gun an start having fun. Air is not hard to find in most locals. You are not using it for breathing, either it holds air or it doesn't. A used tank that will need to be hydro tested in 2 years will cost you less than on that won't need it for 4 years...
Remember if you are going to use a rifle that takes a lot of air due to caliber or air resevoir you need to feed it a lot of air. Also if it uses a lot of air you ARE going to get fewer fills, it is just the way the equation works out.
DonTMN
