See my post #9. If you told her you bought it for her, you might still be married. And you'd have the cannon.
I was at the Battle Of Secessionville reenactment today and there wasn’t much there except for this live fire I managed to get.
http://tysonneil.smugmug.com/History/Civil-War-Reenactment/19681765_XhKFfd#!i=1909475535&k=M4MTg9w
The cannon is almost to the point it is too expensive to operate (namely powder) according to one of the gun crewmen.
I did get a few short clips of some pre-load/load/afterwards that are in the shutterstock approval queue.
Here is a civil war oddball some of may have seen before called a Williams Cannon or Repeating Cannon that I got to see a while back.
http://www.youtube.com/watch?v=9-3Fsjf1iwE