if you have a licensed film production company a canadian retailer is legally allowed to rent guns to you, but you may not have in your possession more than 3 at any one time. this is contingent on you possessing a valid film production license as outlined at www.cfc.gc.ca
and you finding a retailer willing to rent them to you. you can try specarms as Will does that (or used to anyway) or any retailer who imports. if a retailer has a license to import prohibited devices for film production (the one everyone talks about for airsoft) then that license is for the express purpose of rental to ONLY licensed film production companies. if you don't have a registered company nor a licensed film production company then you're pretty much stuck buying at retail.