SpudFiles

this is a pretty obvius design idea its very likley that some one has thought of this, infact the semiauto Eclipse is powered similarly, I have even thought of a potnial problem before: once the valve opens the presure is being lost almost and the (pnematic or metal) return spring may be reopened prematurely, having a strong return spring makes this worse, so I don't know why you would make it pneumatic cause that are usally for stronger aplications when you could just buy a metal spring at the hardware store

Did I say no one else had thought of it?

But normally, in the end, the credit goes to the person that builds the first working prototype, not the inventor.

Anyway, it's pneumatic because you can fine tune it exactly.

Use GGDT to estimate the pressure the chamber falls to when fired, take a bit off, and then set the mini reservior to this pressure. Also, a correctly built bolt could also provide extra force when pressure remains in the barrel. The problem you stated is by no means really a problem.

I think you would have to set that up with a regulator and a high volume of high pressure air if you want a repeater. If the small chamber is set at a specific pressure, the main chamber has to function at a constant as well. At least if I'm understanding the system correctly.
Mine will have to be a cruder system that basically slams the hell out of the bolt for the first few shots and then tapers off to optimum and then fades away.

duh thats why we have compressors