Does it matter? There is very little rhyme or reason to our laws. Someone probably saw them in Gun Digest and said that looks like it should be illegal et voila.
Prohibited Devices
Former Prohibited Weapons Order, No. 9
1 Any electrical or mechanical device that is designed or adapted to operate the trigger mechanism of a semi-automatic firearm for the purpose of causing the firearm to discharge cartridges in rapid succession.
2 Any rifle, shotgun or carbine stock of the type known as the “bull-pup” design, being a stock that, when combined with a firearm, reduces the overall length of the firearm such that a substantial part of the reloading action or the magazine-well is located behind the trigger of the firearm when it is held in the normal firing position.
https://laws-lois.justice.gc.ca/eng/regulations/sor-98-462/fulltext.html
