Better read again. Page 79 of the ON hunting regs.
Firearms
If you are hunting small game in an area where there is an open
season for deer, moose, elk, or black bear, you may not possess or use
a rifle of greater muzzle energy than 400 foot-pounds or shells loaded
with ball or with shot larger than No. 2 shot (or if using non-toxic
shot, you may not use steel shot larger than triple BBB steel shot, or
bismuth shot that is larger than double BB bismuth shot), unless you
possess a valid licence to hunt deer, moose, elk or black bear as the
case may be.
A person hunting small game may not carry or use a rifle of
greater calibre than a .275-calibre rifle, except a muzzle-loading
gun, in the geograhic areas of Brant, Chatham-Kent, Durham,
Elgin, Essex, Haldimand, Halton, Hamilton, Huron, Lambton,
Middlesex, Niagara, Norfolk, Northumberland, Oxford, Peel,
Perth, Toronto, Waterloo, Wellington or York.
