Okay, As op asked....Would it be okay if he or his friend exports/brings it in to Canada from a post box...You are talking about something totally different, you are referring to the ITAR $500USD exemption on some parts ( which some firing pins may fall under) which can only be used and claimed by a DDTC Registered Exporter (not just any business, nor a foreign individual traveling in the US).
just curious, couldn't source one in Canada? bet western gunparts has them
A couple of months ago I was in need of a firing pin for my '92. Searched all over online Canada and US outlets. Brownell wouldn't ship to Canada (I know they do for some things but firing pins are not one of them). I went with Numrich. The total cost - including shipping, taxes, and whatever else they charge - came in less than I could get it anywhere in Canada and the estimated delivery time was a week quicker. It came in 12 days quicker than the estimate from an outlet in Edmonton and $43 cheaper.