Geezuz! Again? It's not all of Southern Ontario. Only some counties and townships/municipalities. Some say nothing greater than .275 for small game only. Some say .270 for hunting anything. And it goes by the cartridge name, not the bullet diameter. Daft? You bet.
"...needs to be changed to a 223 or lighter..." So you think a .223 won't kill? Or travel as far as a .270?
"...what the regulations are out west..." Which Province? Every Province has its own rules. Alberta says nothing less than .23 calibre for big game. And no muzzle loaders less than .44 calibre.
"...how f**ked up and backwards the Ontario laws are..." Written by civil servants who know nothing. I particularly like the Etobicoke by-law that regulates bath water temperature. Mind you, that's to ensure tenants have hot water. Guelph, on the other hand, doesn't require a landlord to provide hot water at all.
Like SuperCub says, there are stupid laws everywhere. No logic to any of 'em. Pennsylvania, for example, doesn't allow semi-auto's for hunting. Another State(forget which one. Indiana, I think.) doesn't allow rifles at all.