You should look at all ballistic chart data. Then choose the 1 you like. I use the "point blank" method. This takes the guess work out while you are in the field hunting and it is tried and true for thousands of hunters. Remember you have to hit an 8" vital zone of deer sized or larger animal. You sight in 3 1/4" to 3 1/2" high @ 100 yds. This allows you to hit the vital zone from top to bottom @ any distance out to about 350 yds. This is like zero @ 200 yds but you only need a 100 yr range and it is much easier. Jim