I would love to have that in my back yard just so I could say hello to the neighbors every morning. I made a much smaller (home made)version that mounted in the back of a truck bed. We used regular black powder andsmall to meduim ball bearingsfrom salvaged oil field equipment as the projectile.
I watched a program on tv once about shooting cannons and motars, it looked like it would be a lot of fun. If anything, it sure would smell up the area with all that blackpowder.
Join the North-South Skirmish Association. A number of teams have artillery crews. The cannons range from smoothbore to rifled. Some teams also have mortar crews. Check out their website. Plenty of cool pictures.