http://www.cfc-cafc.gc.ca/compliance...letin-19_e.asp
Read and learn:
Air Guns and Air Soft Guns
Air guns with a velocity of less than 500 feet per second are not considered firearms for licensing and registration purposes. For most other purposes, however, these air guns are considered to be firearms rather than replicas if their projectiles can cause serious injuries. Air guns that look like real firearms but that cannot cause serious injury fit the definition of a replica. In some cases, ballistic studies may be necessary to determine if a particular air gun can cause serious injury.
Some devices commonly known as "air soft" guns may qualify as replica firearms. For example, following a thorough assessment and a review of ballistic studies, the Chief Scientist for Firearms at the RCMP's Central Forensic Laboratory has determined that a line of electric guns, spring guns and gas-powered guns produced by the Tokyo Marui company are replica firearms because:
They closely resemble real firearms in size, colour, appearance and configuration, and
The projectiles that they fire are not likely to cause serious bodily injury.
Again, various makes and models may have to be assessed on a case-by-case basis