OK, Dick. Maybe in another 39 years of exclusive handgun hunting I might have a clue what's going on.
You're gonna love the BPlex. I shot a groundhog a few days ago at 412 with my 6mmAI Encore. Ranged him, put the plex that matched 400 slightly above him and dead 'hog. Pretty easy.
A little clue, for most calibers below .30, if you sight in 2 1/2" high at 100 you'll be dead on at 250. Each Plex is another 50 yds. and top the bottom crosshair is around 500. Not exact, but pretty close, depending on the round.
For anything over .30, use the 2 1/2" high at 100, then dead on at 200, and each Plex is 50 with the bottom crosshair 400.
.30 cal. is the only cal. that doesn't fit this exactly.
It's really cool with my .375/.284 to shoot deer and groundhogs from 350 to 400 with witnesses. They can't believe a round that big will do things like that at those distances. I live and breath this stuff. Helps keep me young.