Yep, I have some cannons with a 2" bore and a plumber or jeweler's acetylene torch (I make jewelry). I sometimes fill a cannon barrel with acetylene and touch it off. Makes a good bang although not as good as loading with black powder. There are also "Bangsite" cannons which have a thin steel barrel and a place you put calcium carbide and water in which releases acetylene gas and a little friction igniter sparks the cannon off. They have made the Bangsite cannons for over a hundred years and still make them today. Pretty good bang without using gunpowder. Of course the modern way to make a bang is to put a chunk of dry ice in a plastic soda bottle, add some water cap tightly and get away or toss it away from people. AMAZING bang!! There are youtube videos of the dry ice trick, pretty cool bang without gunpowder. Easier to get dry ice than acetylene or gunpowder. And no smoke or fire.