A 308 with a 180 monolith (Barnes, Etip, GMX Trophy Copper etc...) will kill any moose or smaller critter with a clean, accurate, broadside shot anywhere inside of 400yds. (& yes big bears have been taken with it but prudence says when the game might get pissed & come looking for you, use MORE gun than is necessary!)

As for the 50cal mzldr, with a plethora of loads & bullets available today, you can kill ANYTHING on the planet given reasonable distances & proper bullet placement!