I am glad they put something out there. There is already a rather unknown model artillery organization, with some specified safety rules. The NMLRA could use this to attract some new members and to perhaps avoid some safety issues. There is a lot of expensive junk out there sold as blank cannons and some dangerous looking mortars used to fire bowling balls. I know of two fatalities over the last 20 years within 200 miles and there was a rather alarming "catastrophic failure" at Ft McHenry just a few years back. I see several posts a month on face book pages concerning small decorator cannons that people claim they fire, or bought for firing. And some of the stuff sold on ebay truly scares me. I don't have anything large. But between cannons, thunder mugs and salute pistols, I have a dozen pieces to liven up the fourth of July.
25 yrs ago, I attended a rendezvous that had a cannon match. It was extremely interesting and fun to watch, but not very well planned. The target was a 4 x 8 sheet of plywood set up on a sandbar out on the Missouri river. Firing was done from shore to the target, perhaps 2 tenths of a mile out. Seeing the cannon balls bouncing on the water was rather spectacular. However, the farmer out working is field on the other side of the river was not amused by cannon balls bouncing through his fields, especially with him in those fields. I remember him pulling in with his truck horn blowing and the door was open and one foot down before the truck even stopped. His vocabulary and tone certainly indicated a highly excited attitude. Now considering the trip north to the nearest bridge and then back south, it probably took him 10 minutes at 80 or 90 miles per hour to arrive at the rendezvous grounds. As I recall, the remaining artillery matches were called off.
I have worked and trained under A group here in MN, that has been around since 1863(do not want to say group right now). And I/WE do live fire demo's, yes there is a rigid training program, and a test to take. Me and my wife have passed it, so I do live fire demo's now. Just don't make a mistake or you will know about it.