I doubt that it's a Mossberg as they typically had a left/right thumb safety at the rear of the bolt. This gun seems to not have a safety.

Further the thumb screw is typical of some of the Savage single shots.

There were some Winchester branded shotguns made in Canada.....while I'm doubtful this is a Winchester I wouldn't rule it out....I'm not aware of any Winchester bolt shotguns.

Thx guys for ur help, here are some additional pics that show the markings on the shotgun

Here are additional pics that also show the markings on the shotgun