If you want to shoot fast, air is the way to go. Not only will it deliver a more consistent pressure, but it wont freeze your gun into a block of ice.
Most electro guns will only run on air, anyway. It is possible to run some on CO2, such as the impulse, but again high rates of fire will not be as achievable.
Most electro guns will only run on air, anyway. It is possible to run some on CO2, such as the impulse, but again high rates of fire will not be as achievable.