I recently bought a Leupold 4.5-14x40 AO Tactical w/ Mildots to put on my 700Police. I absolutely love the scope, I just have one question. On the power adjustment ring, there are 2 sets of numbers. One is pretty darn obvious, its the power you are set to....Duh. The other reads Yrds/M and is graduated in increments of one from 2 to 6 or 8 I think. What exactly is this for? Sorry if I sound like a putz but I havent a clue about this. Thanks!