I don't expect any rangefinder, even the Vectronix Terrapin-the other unit I am considering, to actually range a chuck at that range, but it does need to range the ground, or rock, the critter happens to be standing on. I've been happy with my Leica thus far, but I am now moving beyond its' capabilities. So far, in this thread as well, the folks who are actually using them seem to speak highly of them.