It looks like you can bring a gun for hunting or competition and that's it. Please correct me if I am wrong.
Here's the actual
form .
See question 6.
6. Provide the reason for bringing firearms into Canada
O Hunting
O Competition
O In transit
O Protection against wildlife
O Other, specify
12 gauge with 3" rifled slugs , right behind .338 Winchester Magnum and .375 H&H Magnum, as recommended
here . And much easier to handle and more versatile, in my opinion.
Despite this link, it is ALWAYS better to avoid dangerous situations than to try to get out of them.