I've never noticed a dime's wort of difference between anybody's swaged balls. Cast balls are a bit different. I've seen some that were almost Lyman number 2 alloy they were so hard. My own cast balls are as pure a lead as I can find.
No problems with taking whitetails at 100 yards using a .50. Sight dead on at 100, and as said above, trajectory will be flat enouh to hold dead on at any range up to 100.
I've never had a deer run more than 40 yards with any round ball, and most don't make it 5 yards.