I'm comfortable to 75yds for whitetail. The bigger they are the closer I'll get.
The round ball loses energy/velocity far too quickly. If you want to take a longer shot then go with a good conical(there are many out there) bullet.
But then, type of projectile will depend on your rifle twist. 1:28 is common in most/all in-lines, 1:48 is ideal for conical & rnd ball. There are of course other rates of twist but these two are common.The .50 will drop all big game as long as you respect it's limitations.