I’ve been told in Newfoundland not to have my shotgun in my car outside hunting season without a permit specific to the carry. It became an issue when I wanted to set up a private trap for a few friends to shoot skeet.
My understanding, in Newfoundland at least, is that rifles and shotguns can only be transported during hunting season, and that includes such things as sighting your gun - have to wait for the season to open.
On the other hand, when I’m in Ontario, I don’t think twice about taking my shotgun to my local skeet club regardless of season. It’s clearly legal, but maybe the destination matters.