The difference between the ball and conical is that the conical can be made heavier and as such it will carry ENERGY farther downrange.
From what I read before getting into rock knocking, 400lbs is what you want to hit a deer with. Dont know if it is true, but you have to start somewhere. A .50 will carry that to a bit over 100 yards, (120ish if I remember)with a fairly stout load. A conical or larger round ball will carry 400ft/lbs farther.
Now if you figure out what your bullet drop is with your load using a ballistic table and or shooting at different ranges, you can figure out where you want to hit at a given range to keep the ball in the kill zone. Ex, my long home range is 127 yds over a valley, and the short is a max of 40. I dont have good 50, 75, 100 yard ranges to play at, so I found a table and figured about 4 in below point of aim at 127 is within a kill zone from 0-125 yds.
My personal max is 100 shooting PRB, even though I know that the bullet will not drop out of the zone, AND I know that the bullet has plenty of steam over that range, I like a little wiggle room, and a shot at 100yds or close to that will only be with a rest. I shot the only deer I have ever taken in 4 seasons of flintlocking at about 75-80yds from a rest. I took her in the neck and the bullet passed through right to left.
I shoot a lot of open and peep sights and only got a rifle with a scope on it when I was in my mid 30's. Open sights are not a problem IF you practice with them.
So if you want to take the base numbers and add wiggle room, 100 yards with a 50 caliber is perfectly do-able. Conicals could extend that range but you would have to figure your drops and that would be a pain in the woods.
Our forfathers were shooting a lot farther at things that shot back. However the idea was to put a hole anywhere in the target, due to lack of medical knowledge it was a kill. We are trying to punch a hole into a 6 inch circle to do enough damage to take a animal quickly.