RE: TORONTO shooting range....
I think your going to have a hard time finding a range that will let you rent time, they survive because of the membership. I know of only 3 rifle ranges near Toronto, one is in Cambridge off Hwy 25 and 9th concession (can't remember the name), the other is in the Niagara/St. Catherine's area (no idea where it's located, but I have heard it refered to as Silverado???) and the last is the Oshawa Gun Club off of Ritson Rd and Coates (not 100% sure of the location). Sorry I can't be more specific. I would try emailing the clubs to see if a member would help you out.
Its a pain in the butt to sight in a gun around Toronto, most hunters wait till they head up to camp but that doesn't provide practice time.
I haven't looked into the costs but I hear its a good buck.
Good Luck,