Hello,
I have taken muskox and moose with a .243 but I live in the Arctic and smaller calibers, short open ranges (usually), and head/neck shots are the norm when hunting.
In S Ont, a larger caliber is probably best. If you are a new shooter, recoil may be a consideration, but dirt/range time will make you more comfortable with recoil and improve your shooting/handleing of the firearm.
IMHO.
Lou