At this present time, owning a cannon would be frowned upon, but after it has all gone to hell in a hand cart & there is no longer any law enforcement to protect us, then anything goes, right? So, if you are looking for some big guns, now is the time to get them. You can pick up hydraulic rams for a song second hand, sometimes totally free. It will take very little modification to turn one of these into a Black Powder cannon. I am sure if you look at the images below you will instantly see the potential: Just remove the piston!