SpudFiles

Well I have already a lot of how-to's on making piston for my next project, a multi shot pneumatic, and decided that I would make a chamber sealing piston, because it's the one I understood the fastest. Here is m design, pretty self explanatory:

I didn't bother to animate it all the way to the end, but it's not realy neccesary.
And here's the basic design for my gun:
http://h1.ripway.com/Strangers007/Pics/ ... 3-shot.JPG

makes sense, will be a bit awkward to operate (you should find a three-way valve to replace the ball and sprinkler valves) and what are you planning on a breech reloading mechanism?

That design looks pretty good, but does that piston really need the guide rods?

The breech loading is for a hybrid golf /ping pong ball launcher:
http://h1.ripway.com/Strangers007/Pics/ ... ybrid.JFIF.
What I could do is replace the ball valve with a sprinkler valve, increase the gap between the valves, reorient the pressure gauge and use the brass for a stock and hold one blow gun in each hand.
I guess it would look something like this:

I don't know if it needs the guide rods, but I'm leaving them just to make sure.