Canada's export is pretty free. The US import is the tight side from what I know, as long as its not an ITAR controlled item it should be free and clear. Usually things with cage codes. There is a Local guy here that has been making a very popular hand guard for Bushmaster ACR type rifles and 90% of his buyers are in the USA. Ive never heard of him having issues with his sales cross border.Any issues getting parts made for guns out of Canada?
Or making psrts for guns in Canada?