The new leupold VX-III scopes with the wide duplex have a "range estimating" feature. The bottom post has a cutout that you center on a 16'' target and then zoom in on until the target then fills the cutout--numbers on the back of the zoom ring then estimate your range for you. Has anyone tried this system???? If so, how did it work. More importantly, for me at least, is this: If you went through the same process with an 8 inch target, would you be able to estimate your range by doubling the range given for a 16 inch target??? Any help would be greatly appreciated.