Maybe? Flintlock muskets were fairly new technology around the US revolution - less than 100 years before that, people would have been using match locks and arquebuses - relatively the difference is probably similar to the difference between a smith and wesson revolver and an AR-15.
Did “right to bear arms” ever include larger weapons like cannons? I’ve kind of wondered why the second amendment doesn’t cover larger and more destructive things.
Tough question to answer. Historically, privately owned artillery has been OK and was crucial during the Revolutionary War and all sorts of little skirmishes throughout the 19th century. It still is OK with the right tax stamps, but that doesn't say much about the natural right side of things... just because you can own them doesn't make ownership constitutionally protected. My pet theory that I've espoused on here before is that the 2A, in part, protects at minimum "bearable arms"- essentially a soldier's personal weapon. There's a very big gray area outside of that though, especially in regards to anything that explodes.
You can own a cannon today. I think you can own any type of cannon that was manufactured before like 1890 (memory is fuzzy here), a "saluting" cannon for funerals and what not and otherwise you have to pay for a tax stamp then wait for the paperwork to go through. State laws vary.
Cannons are pretty neat devices to construct, especially if you try to do bore drilling with any period accurate methods.
At the time, a militia was a whole-community thing. The town would have an armory, and the town militia would get together for exercises, check out weapons, and put them back, after. Carrying a gun around on daily business, you would be thought deeply peculiar, unless you needed it for work. "Concealed carry" would have seriously creeped people out.
And yes, the armory would have had cannon that would be practiced on.