I checked the Canadian regs.
It seems that I do not have to be either a citizen nor a resident to get a regular PAL ($60) or a PAL ($80) that includes restricted guns (handguns, AR's).
As a non-resident of Canada I can also simply get a NRFD (Non-Resident Firerms Declaration) good for a year for $50 and not have to register them, but instead just declare them at the border or port of entry.
The NRFD is good for unlimited crossings and entries. You just re-declare them to customs and a new number is issued. The NRFD acts as the temporary registation for your firearms while you are in Canada.
If you get a PAL you have to register them, but it doesn't expire in a year. You can also use it to buy guns while in Canada just like a Canadian.
Interestingly enough, in Canada percussion blackpowder weapons and airguns of a velocity of over 500fps are considered regular firearms, which they are not in the USA. In the USA, for instance, you can order percussion revolvers through the mail, no paperwork.
As a non-resident you can bring in 200 rounds of ammunition tax free, over that you pay duties on. Canadian residents can bring in 5000 rounds plus 5000 rounds in components including 8kg of powder.