When you use Co2, it is placed in your bottle as a liquid, but expands into a gas before reaching the marker, the marker does not "turn liquid into gas". You never want liquid making it into your marker. That's why it's advisable to use an expansion chamber and anti-siphon tube, so that you eliminate as much of the liquid reaching your marker as possible. Many people with 'cockers and impulses use Co2 and air interchangeably. Nothing wrong with it as long as you run an anti-siphon tank and set yourself up with a good reg for Co2 (like the Stabilizer or Maxflo). While air and Co2 are totally different, they're not so in the way that you believe they are. I'm not sure how much you know about 'cockers, but given the symptoms, I'd be very much inclined to believe that the problem for this person is sear lug timing.
