It's natural to carry heavy tools on the shoulder, like picks, shovels, belt-fed machine guns. It provides some variation when carrying a break action shotgun open and unloaded, especially one with 30 inch barrels.
When I carry a rifle or shotgun on the shoulder loaded, it is muzzle up, with my hand on the grip. If anyone else's muzzle even comes close to pointing at me, I don't hesitate to push it away with my hand.
