There’s a hilarious description with pictures here:
http://www.docsmachine.com/nonPB/mortar.html
of a guy who built himself a black-powder mortar that launches bowling balls a good 600 yards downrange.
Once upon a time I went Shootin at Lion Den Dans place. one of his pals had a 4”. blew beautiful hole in a fridgerator bout 200yds down range! cool stuff!
https://www.youtube.com/watch?v=Sx6876ERbiY
There’s quite a few bowling ball canon and mortar videos on Youtube. I love America.