Heavier ball, less prone to being thrown off by high winds, Packs more punch at the receiving end.
I dont even bother looking at 50's anymore. From now on i've gone .54cal+

.50cal roundball is 177 grains while the .54 is around 230 grains.

Just traded for a 58cal too.

73 huh? Well you know the saying, The older the bull, The stiffer the Horn