Those cannons are sold without a touch hole for liability issues. They aren't meant to be shot.
Go to this website muzzleloadingforum.com
Click on ;cannon.
Click on ; miniature napoleon cannon. Have look at the barrel in particular,quite a difference in wall thickness and the steel that was used.
There is also a thread about cannon disasters, not very current though, no mention of the youngster than was hit in the head by a chunk of barrel, 100 ft away from the exploding cannon.
Dixie gunworks, sell a working cannon much like yours, more expensive, defiinatly the safest route to go .
Cheers nessy.