If I'm shipping my personal firearms to say a gunsmith, etc...I usually try to ship them in a padded hard gun case, which is then placed inside another cardboard shipping carton. Makes it non-descript and makes sure my firearm is protected from the worst that Canada Post can dish out. Use lots of packing tape and I now use extra duct tape on all corners. Have received too many parcels from Canada Post with stuff hanging out of them because the cardboard was damaged, or in winter, soaked apart from snow, slush or standing water.