not sure about Canpar, but some couriers I've dealt with - Loomis for one, require a "1.4S hazardous goods" decal on the outside of the box. It's easy to copy the image from the internet and print and paste on a carton. they may also require MSDS. ( Material Safety Data) sheet. You can download that from ammunition manufacturers website. One more thing is to declare " limited quantity" which avoids much of the red tape and paperwork and Hazmat charges. If you meet those requirements more shippers will take the goods.