That's actually a bloody good idea... you'd want to 'sandwich' a transfer port between the barrel and air cylinder, and your loading bolt would need to push the pellet far enough into the bore so that the pellet skirt passed the transfer port 'hole'... if you were really smart, the same 'bolt action' could also cock the trigger, just like a real gun... gets a bit complicated then, because the trigger would need to release some kind of a spring loaded hammer or striker - to knock on an exhaust valve...
Nah, too complicated. It'll never catch on.