I used to think that I was pretty good at estimating ranges until I got a rangefinder and realized that the canyon I was missing shots in was 225 yards across not the 400 yards my guesstimate had been. Since then I've graduated to a Leica 1600 crf and there is no good excuse not knowing how far my target is away in even poor visibility conditions. Now the limiting factors are wind conditions past 300 and access limitations. I've had a bull elk on adjacent public ridges less than 400 yards away with no legal means of recovery from the public parcel I was sitting on watching him graze, and several times where you can see them but can't get to them in less than a few hours of walking and driving . But on those occasions where the ability to make a a 500 yard shot is the difference between coming home empty handed or with full coolers and horns the practice is very worthwhile. I'd like to go back 30 years before with the equipment and shooting skills I have today - but then again I'd like the eyesight I had in my 20's. Young guys today have better equipment by far - it is a piece of cake to make 500 yard shots at a reasonable cost. The farther out you go the higher the cost in equipment and practice required.