The Talon SS is a cool rifle. If you can swing it , I'd get the CO2 adapter too. On Co2 you'll get around 675fps with an 8g pellet ; which should be perfect for killing rats . I would use 9oz bottles , because of the diameter of the larger bottles creates a need for even taller rings . You'll need the bottle adapter which should come with the scuba tank set you've got coming to fill with any type of air. the adapter will fit a pump , and you would have to rig up something to fit a compressor line. BTW what type of compressor are you talking about? a regular air compressor will not work , it won't go high enough to do you any good. The Talon is a great backyard gun , it always drew too much attention in public places for me , it's a little too tactical looking .kirby