Fire Cracker Cannons

I have the 9" 60mm green artillery cannon like in the stock photo below.

I guess my cannon is actually illegal to use here in Minnesota. I was at a firework tent a few years ago when a cop was sitting in there handing out safety pamphlets with notices of what is legal and what is not when he asked me at the checkout "are you doing any firecrackers and bottle rockets this year?" knowing they are illegal, I of course said "no, I have a toy carbide cannon that makes a nice loud firecracker like sound" he said "oh no, don't shoot that off, those are actually illegal to use here as well, but knowing it is not advertised well, I'll let you know now that shooting it off could get you in the same trouble as using illegal fireworks". I just thought "dammit, buzzkill". I have used it anyway since then, never got caught, neither have I ever been caught using illegal fireworks LOL. The neighbors have been caught before, although they use shells that fly up and emit some large bright balls of sparks that kind of making them a large target.

I have taken a gallon bucket that was used for driveway sealant and placed a bowl of water under it, mixed some calcium carbide in the water, let it sit for a minute and then used a modified outdoor lighter to emit a spark under the bucket. That bucket shot up a good 3 feet. I did it 3-4 times until the plastic bucket cracked down the side. I would have used a metal bucket or can but I didn't have that around then.