My uncle has a 72 caliber Bess and I can certainly say when I saw it I was in awe many years ago. I wanted to fire it and he made me a bet that I could not hit a sheet of 4x8 plywood at 60 yards. I said absoluetly I could. We loaded it up and here I go to shoot and miss it!! I spent all fall raking up his leaves in his yard and learned a valuable lesson about smooth bores.
That show is a good one and here are other ones to watch.

http://military.discovery.com/videos/triggers-videos/