Sure, they still make 10 ga. saluting "cannons" for the yachting crowd.
Last I saw they were a couple of hundred for the low-end, went up from
there as cosmetics were added. See:
http://www.bellmorejohnson.com/
Looks like they've about doubled in price since I last looked at them.

Copies of the original Winchester design. A whole lot safer than
trying to make your own out of gas pipe and firecrackers, AKA
"grenade".

Stan