Before there were liberals a person could own cannons.
You can own anything you want. Liberals be damned.
Just be sure to keep it secret so they don't know about it until it's too late. (-;
Liberals or not you can still own a muzzle loading cannon with no restriction. A breech loader takes a little more paperwork but it can be done. Just to make the point one of my neighbors owns an 8” M115 howitzer that he restored to firing condition. And I still say a person of sound mind should be able to own anything the police or a municipality can own. One of our local ski slopes has a 105 howitzer on loan from the gummint to prevent avalanches. And I want one too.