Re: HORUS VISION
Take your dope in MOA if you have it, and divide it by 3.438 and that will give you your dope in Mils, to which you can simply hold the appropiate line on the reticle.
Or you can use a free ballistic program and input your caliber, MV, etc and have it output in Mils and that is the line you use.
for a 308 you basically use,
200 - .5
300 - 1.5
400 - 2.2
500 - 3.5
roughly, etc...