An variable scope can be used as a crude rangefinder on broadside animals- You just need to know how large the animal is. Say it's a deer, about 18- 20" top of back to bottom of chest, and you are using a 3-9 scope.
You put a 18" target at various distances, and record it in comparioson to your reticle. So say it's at 200 yards, and it fills the top of the post to the crosshairs at 3X. Record that. Do it again at 300 yards. It's 5X. Record it. Etc. Then hold accordingly, because you already know your bullet drop, rigth?
This works pretty good, but probably loses precision at distances over 400 yards.
Mildots and extra crosshairs work pretty good, too. But you still need to know the distance, and they are not 100% precise, since the manufacturer of the scope doesn't know if you are using a 300RUM with a sleek bullet or a 308 with a jelly bean. Mildots sure work for "ranging" if you can see the bullet impact and the corresponding dot.
I think the easiest, least complicated and most precise method is to use a rangefinder, know your bullet trajectory, and use turrets on your scope.
Range, adjust turret, point and shoot. No guesswork, no memorization, no need to see the animal broadside to check the range.
