Steve -
I finally had some time to chase through the links that you posted.
THANKS - it has influenced my thinking on what I want to build in several directions!
First to build anything under 3/4 inch didn't seem worth it until I saw some of the small bore handgonnes pictured in the links.
Second, there were some early, more hand cannons rather than pole gonnes that looked like they'd be fun to build and shoot.
I was, and guess I still do recommend using 1-1/2" diameter stock for a handgonne - only because it just feels right in weight and balance. Don't be afraid of the 0.90 bore - the kick on a 1" piece of 3/4" copper tubing isn't at all brutal - it could be lots more and still fun to shoot.
So do both - one in about an inch and another in about 1/2" bore!
I'm glad you like the links. I find handgonnes interesting since they're from the dawn of BP gunnery before guns & artillery diverged. It seemed like the difference beween a gonne and cannon was really a matter of size than anything else.
Two or more sizes might be a great option. I'll bet tyhe lighter sizes were for more mobile forces and the larger were more for siege situations. It might be a cost saver to make the multiple gonnes in the same design - just scaled up and down.
These are rally exercises in lathework more than anything since trunnions hadn't yet been invented. If this project gets rolling, the members could be checked to see if there is an interest in larger sizes. Early cannon were just fastened to their carriage/platform. One really ineresting early carriage design was a split carriage with a top and bottom half. The barrel was on the top half which raised and lowered with a metal piece in the back with holes for pegs. The upper hald would have its rear rest on that.
In the US we tend to prefer Revolutionary or Civil War designs. It would be so cool to show up with a really ancient design at a cannon shoot.
Steve