Re: barrels for canadians?
I've had a few gunparts shipped from the USA to Canada, basically its all in how the product is labelled.
Fiberglass sporting goods (rifle stock) was one of my personal favorites
Telescope (rifle scope)
Also if the part has a value of less than $100 ;) then there is no problem either.
Some companies are really good and some just don't want to bother with selling north of the border, phone some companies and talk to them about it and see how they want to deal.