Many good comments here. I agree with speedbump's approach of KNOWING the size of your intended target, and with p dog shooters suggestions. I now use my laser rangefinder for most of my ranging, the exception being the quick glance made through my ranging reticle to verify if an elk is within 300 yards, in which case a dead on hold is all thats required. I use a figure of 27" top of back to bottom of chest for a mature bull. Thats 1.5 mil at 500 yards, which is also the hold over with my rifle for 500 yards.