For the past yr. or so now i've been checking out something that's been working pretty good so far. While i was looking into the mil-relation formula, i started wondering if the system could be used with any reticle with a stadia out of the optical center of the scope once it's subtension was known. Turns out it works just fine, especially when all a shooter has is just a plex reticle. Here's how it works-- just substitute the stadia subtension measurement for the mil reading, i.e. target size x 100/stadia/# stadia units. For example i was using a 4-12X Burris Mini on a 17 Mach IV XP for coyotes. The plex gap measures 5.7" @ 12X, so plugging the #'s in figuring a 10" back-brisket coyote gives, 10 x 100/5.7/# stadia units (SU), or 1 SU= 175 yds. .9= 200 .8= 220 .7= 250 .6= 290 .5 (x-hair)= 350 etc. Seems to be working pretty good for me so far. Anybody ever use anything similar.