[quigly]

I don't think it would be possible with the CO2 conversion. How ever, if you had a CAD program, and access to CNC equipment, or just out source to a metal shop, you could make your own mech using the base of some kind of GBB pistol. It would be a lot of work but the end product would be hell of a lot better quality, and way more bad ass. This would take a lot of time and money though. That's the main issue with builds like this. $$$$$

 

[quigly]

It's all about design, then trial and error. There are ways to make it shoot hotter by adjusting different ports and such.

 

[quigly]

For sure. Try looking for CAD videos of GBB pistols, and it can help you with the basic design a lot. It's always better to start with a basic design and build up then starting from scratch.