Just going to stick this.....
I think I am still going to play with it and see what it does in a DSG build. I am not expecting much out of it. But you never know. I think I will need to completely remake it though as I do not want to wreck my original one and make some tweaks to it. Hmm... half the volume, barrel... This project is going to be silly...I don't think it would be worth it (could be wrong). An AEG piston o-ring releases it's pressure once it has stopped moving forward and air can come from behind it. That is pretty much the same as the PDI Vacuum Piston.