Just make an air reservoir in the back, with a solenoid that will let the pressure through in the nozzle, with a switch in the trigger. Easy. Then you could run the gas line through the back of the bolt, through the handle.
You could even do it, you own a lathe, and steel is fairly cheap right now at mcmaster...
You could even do it, you own a lathe, and steel is fairly cheap right now at mcmaster...