Mil range estimation is a lenghty subject. The reticle MilDots must be calibrated to a specific power (probably 10 on your Leupold) of in the focal plane that is non-magnifying. If you do a search here about mildot ranging you'll find a ton of info.
You can check your scope by painting or taping a few 4" stripes on a piece of cardboard or anything else and verify your mildots on it from 111 yards, or just paint or tape 3.6" marks and verify the mildots from 100 yards. You should verify ALL the mildots on your reticle (horizontal and vertical)...sometimes they're a little off from the Leupold factory (I had one like that).
Get a MilDot Master from Bruce Robinson... it'll be money well spent.