I have learned that basically you need to find out what your rifle and sights can do at 25, 50 and 100 yards.
Not 2 muzzles will shoot the same and any variation to the powder has an effect on point of impact. For a scoped rifle shooter it can get right down maddening but it's fun.
I started at 25 and went up from there, as soon as I got a bullet/powder combo that gave me the tightest group I was happy and kept it.
My limitation is 110 yards with open sights, I can hit a inside a paper plate all day long, for me that is as far as I feel confident in making a kill shot on a deer size animal.