I just bought a VX-III with a Varmint Hunters Reticle. I have yet to put it on my rifle and shoot it, but I spent 3 months trying to find the 'right' scope. The concept behind this type of scope is sound, but depending on the caliber you are shooting depends on what power you have to have the scope set at. The system works on bullet drop at 500 yards and the calibers are seperated into 3 groups. You can look at the caliber groups at this link http://www.leupold.com/products/BAS/BG_Cartridge_Chart.swf
Because this Leupolds system includes so many calibers they can't be exact for all calibers. I can't wait to puttheVX-III on my AR.