i would follow the ballistics chart and be .70 at 25 yrds. this will make it easier to get the tighter pattern and you won't have to do as much walking it will also be easier with the spoting scope. But remember if you do it at 25yrds with a 1/4 moa you will have to multiply the clicks by 4. IF you do it at 50 i believe it is 3 times the amout of clicks