Originally Posted by y0da900
I think that set up like that the valve may fart quite a bit, you are removing the bias from the front side of the shuttling piston when firing creating a bias to push it forward, even with the noid venting.
You might be right. The rearward bias of the back two piston seals might keep it held back, but if the transfer tube is too large the piston would move forward once pressure behind it significantly exceeded breech pressure.
I don't think it would fart though since the bolt would be traveling rearward before the piston started moving forwards.
It would look as if the piston flew back, hit the stop, moved forward, latched onto the bolt, then finally returned with it.
End result would just be a dump chamber that wasn't fully emptied. That might be a good thing though since it reduces pre-expansion inside the dump chamber, increasing efficiency.
If you really wanted to completely dump the chamber, the transfer tube could be moved to the back of the piston and the piston stops could be moved up.
(EDIT: Note the LPA and HPA tags on this image are incorrect. Both ports would be fed by the same source.)
Using LPA via a cheap regulator would waste even less gas through the vent, but possibly not enough to notice? It would have the added benefit of holding the bolt open longer ensuring the entire dump chamber was emptied.
The MQ's solenoid is smaller than originally thought so the back of the piston was shrunk. Additionally I also forgot the bolt backstops so those were added as well. The entire thing might be small enough to cram into an Ion?