The longest that system has worked for me was the 2000 Alaska hunt when it nailed a 1000 yard moose and a 800 yard caribou. Also got a 500 yard chip shot caribou the same way on that trip. All one shot kills. Most of my shots are probably in the 400-600 yard range and it is deadly within those ranges. Most people who do this a lot have there own system that works best for them. The main thing is lots of practice to become comfortable with it. I turn clicks when he stays still long enough but it is always good to have a plan "B" cdefg, etc. Impossible to do this with a cheap scope. Must have exceptional clarity, resolution, etc.