There is a simulator program you can demo and buy at Shooter Ready. I do not know how exact the program is, but it will provide hands on experience using mildots for ranging, plus other variables of long range shooting such as wind and atmospheric conditions. Bare in mind that it may not translate exactly to your scope or rifle/cartridge combination. You should try it if you want to learn how to properly use mildots. One thing you should learn is that even with many of the parts of the equation known, it is no simple task to be able to hit the long range target in the desired location. It takes practice.