Ok, two quick bits of info.
First, there is legislation in Ontario against the acquisition of airguns by minors:
http://www.ontla.on.ca/web/bills/bil...gePrintId=1054
Second, the bylaw in your city prohibiting the use of airguns within your city limits:
http://www.haltonhills.ca/bylaws/pdf/1994-0074.pdf
You might have a permissive relation with your neighbors but a call from anyone passing by is going to land you in trouble.
You're looking at a fine and probable confiscation, and you expose yourself to a world of hurt under various federal firearm acts.