Originally Posted by NO.SPD.LIMIT
Most of the time a welding supply company will have "bulk" 50 pound cylinders. They are very expensive to buy so most paintball businesses rent them. Look in the phone book under welding supply.
Just to add to this:
You will want to ask for High Pressure Bottles
either 3000 PSI, 4500 PSI or 6000 PSI
You will also need the proper hoses, adaptors and fill station.
Remember that Nitrogen might be a little less expensive to buy from them.