Non-Restricted firearms (longguns) in Canada are exempted from additional transportation documents, except PAL firearms license and registration certificates issued by Canada Firearms Centre, prooving legal ownership of such.
Opposite to longguns, handguns can be stored only at the location, where it is registered. Also, in order to transport any restricted firearm (handguns) in Canada individuals must obtain ATT (Autorization to Transport). There are two different types of ATTs: permanent and temporary.
Permanent one will be issued by CFC for a period of up to 3 years, after you became a member of certified shooting sport jurisdiction (gun club) , and usually will be renewed with your membership in it. You can also get temporary ATT, by phoning Canada Firearms Centre at 1-800-7314000 and by providing reasons for it, such as: relocation, visit to a gunsmith, participation in auction or museum activity.