I have several small brass/bronze cannons, two from Dixie and one from Peach Bottom foundry. None exactly like that.
Take careful measurements of the inside of the bore and then compare to the outside. A reasonably safe rule is at least a bore size thickness all around the bore for breech thickness and wall thickness. the barrel looks beefy, but I can tell from the picture if there was drill run out when it was bored or for that matter how thick the breech material is around the cascabel. between the bottom of the bore and the narrow part between the barrel and the ball at the end. (That is where the full size Ft McHenry cannon was too thin and separated) Are the trunnions straight through or cast as part of the tube?
I shoot blank loads with powder and muzzle loading shot gun wads. Some people pack in paper, or whatever. Heard of so much paper being packed down a barrel that is acted like a bore obstruction. When I first fired my 1.25 inch bore cannon, I used a 1.25 wad punch to punch out thick leather wads from a piece of saddle skirting. I poured the powder and then put in the fuse and then rammed two leather wads down the bore. the air jetting out the fuse hole pushed the fuse out. so I stopped, reset the fuse and then much more slowly rammed the wads down. We fired it from the top of the hill on my farm. at dusk. We could see a giant 15 ft diameter smoke ring hovering about 40 ft out from the muzzle. We could see porch lights go on and folks coming out onto the porches all around expecting a fancy aerial fireworks display. We fired three more and my buddy noticed a police car with flashing lights racing along the top of a hill a few miles away. The cop was heading toward a dead end at the top of that hill and there he stopped for a few minutes, like he was looking for where we were located, The smoke was laying in a flat cloud over the hollow be that time. We just decided we did not need any hassles and packed things up. Heard a week or two later that a woman claimed her window had been broken by the boom and she called the cops. Now her house is about a half mile from where we fired and it was a rickety old farm house that was directly in front of us.. I seriously doubt we broke her window.
There was a big re enactor who was the former Mayor of Lancaster PA. he had several original full size cannons and a cannon get together at his farm in the southern part of that county. My farm is 12 miles as the crow flies on the other side of the river, and I can hear the cannons going off at his farm.
If you do fire your cannon, make sure that when you do, it can't roll anywhere. Was at a range near Davidsonburg MD, decades ago and a guy was shooting his little "Old Ironsides" style cannon. The loaded it up and had a firecracker fuse sticking out. The guy leaned against the loading bench when he struck a match. He shoved backward from the loading bench when he got back. Well the loading bench wobbled enough that the cannon rolled backwards and fell off the bench pointing back at the guys van. Yep it went off and right through the widow of his new van. (Don't know if he had Firemans' Fund Insurance, it would have been in one of their ads I suppose.)