I suppose you could use a 50 for hunting deer, but you sure as hell better ensure your shot is backstopped appropriately. Probably mostly morons and the occasional marksman using them, try to stay safe.
Here in BC I'm pretty sure we can still use 22 if we choose to. A friend of my dad's used nothing but to hunt everything from grouse to moose with one up in the Caribou country back in the 1950s, but he was an uncanny shot.
