do NOT use 20 oz co2 tanks... if you do, first problem is that you will need an adapter to put to the tires.. second problem, and the worst, is that co2 tanks dont have a decent regulator on them, and the co2 on the inside is being regulated from anywhere around 750-900 fps as it comes out, and pressure fluctuates rapidly depending on fill level, temperature, price of tea in china, and even humidity.. if you were to use prefilled paintball equipment, you should look on ebay for a large(over 90 or 110 ci)(if you can find any of the really REALLY big ones, they are cheaper, who wants to carry those huge monsters on the back of a gun all day) nitrogen paintball tank, preferably with either an adjustable reg, or a low pressure reg (low pressure regs are present and non adjustable, putting out approx 250-300 psi where high pressure presets put out a failry consitent 800-850 depending on the preset) nitrogen(or hpa high pressure air(scuba air)) is much cheaper than co2, as you will pay 6-7 bucks for a fill on a 20oz co2 as compared to a buck per 1000 psi on a hpa tank, which are rated at 3000, 4500, or 5000 psi, and you can get them filled at diving shops as well as most any paintball field... just make sure to put a REALLY GOOD on off valve in line....
oh, and in case you are wondering, i am volunteer ref and airsmith at dothan survival games in dothan alabama.. i specialize in spyders, and if i say so myself, i can do the best trigger job on any electronic spyder or spyder clone in 100 miles.. i'm also learning how to work on cockers and cocker clones (i just build my first fake cocker from parts..)
wally
