There are probably more 200 pound black bears killed by hunters, than there are 500 pound bears, so my association of the challenges related to, and the cartridges that are suitable for, problem bears weighing half a ton, might be seem excessive...
Quarter ton???
My problem is the platform and bullet choice moreso than the cartridge.
Approximately 60-70% of bears harvested are displaced jeuvenile bears weighing well under 200 pounds.
Over the years we took more than our share of 400-600 pound bears and in all honesty on similar hits, recovery was pretty comparable to a 200 pound bear... take out the lungs and they don't go far.
Having said that, my experiences on bears, have lead me to camp with the heavy/slow crew as opposed to the light/fast crowd... not looking for a debate, just my opinion after handling 250+ client bears and 50+ of my own.