Blank firing weapons are in a different class of law, and we were talking about a very specific group, not all. WW1, 2, and up are still fighting to get reasonable rules established. It's currently easyer for them to use a real Lee Enfield with a blank adaptor than getting a purely blank firing gun.
There is still lots of work to be done to change other things, but it worked for muskets.
The cannons I refer to are from the same era as the muskets, not modern cartridge guns; but they are operational. I've seen privately owned cannon up to 6-pounders. I can buy both with little effort, my PAL has nothing to do with it.
I did say, clearly, that nothing would happen right away. BUT... if we give it time, things can change as the past has proven.
Education; how often do I see real tactics in use at games? Hmmmm, you never do ambushes in your games? How about coordinated assaults? Sniping? Scouting? Convoying? Point defense? Planning? No?
If you dont do that already, what do you do? And where do you think those tactics came from?