I'm by no means an expert in this area but I do have a Nikon 800 that will get upgraded asap. It readily picks up and gives good readings out to 450 yds. Occasionally, it does pretty good out to 500, sometimes 600 if the light is just right. Rarely will it pick up out to 700 or beyond. It is quiet aggravating when you want/need to range a deer or groundhog and can't get anything but "- - -".
In its defense, it will give readings if the object is big enough, say a barn or a vehicle but who shoots at or toward those? The animals don't stand by those objects! It usually picks up evergreen trees pretty good too. Deer at 600 yards? could be hit or miss, most of the time, miss.
Save yourself some hassle and get a Swaro or Leica. More money but better electronics/glass, from what I've read/heard.
There may be others out there that I'm not aware of. JohnnyK.