Okay, I have decided to make a piston valve coax and am making the piston driven by a smaller piston as the exhaust valve. I am near completion of it and will start a new thread for it when complete.

But for me they have very limited mobility.

Tech I was thinking about a piston cannon or maybe an advanced combustion. I can't decide which I want to do because I can only fire the piston cannon near to my compressor but if I make a combustion I can transport it wherever I want and still fire it.

Here are some damage shots and picture of the paint scheme. I was shooting at 3/4 inch MDF because that is what I had laying around. I took three consecutive shots without having to make new ammo. It didn't do as good of damage as I had hoped but I was using air compressor pressure so it was only at ...

I don't really plan on servicing it. If it breaks or fails I can just make another one. It wasn't expensive enough to worry about. I'm working on ammo for it now and once I come up with something I'm happy with I'll try to get a video of it in action, or at least some pictures of the damage.

I am a new member here and after looking around for a couple of days I found this post http://www.spudfiles.com/forums/viewtopic,p,282119.html#282119 which was a question about a design for a coax cannon. I have made simple combustion cannons in the past but wasn't really familiar with the other ...