And in other countries, they make no distinction between a black-powder blunderbuss and fully automatic military weapons - they're both equally hard to obtain, so the people who do get a gun end up with a select-fire rifle.
Pistols are often more heavily regulated than rifles, because they're concealable.
In the USA you can just buy a black-powder cannon if you want. Artillery not so much if it is autoloading. The "own a musket for home defense" copy pasta comes to mind.
Is this... common? Can't imagine why anyone would want one.
(It's probably $5k to $10k to get a working cannon, and most owners are probably reenactors and movie-proppers.)
There was also a tradition at our high school to shoot off a cannon each time our football team scored a point at home games (just the powder no projectile).
Oddly, crossbows are also restricted, though may be licensed as above; as I understand it this is due to a legislative error which no-one has gotten around to fixing.