Find what works for you. What I've discovered over the years is that when closer shots present themselves <100 yards or so I want it right on the crosshairs. I used to site in 2-3" high at 100 but discovered the hard way that when an opportunity appears at closer ranges it normally requires a VERY quick shot and with everything else to consider (safe back drop, is it the animal I want, any lead if running, etc) the last thing I wanna do is to have to figure in bullet RISE too. I've either shot high or worse - spine shot taking out precious back strap!
With that said, a couple years ago had a confirmed lasered shot @ 495, one shot into the bolier, three four steps and down, no followup needed. My take (and experience) is that IF I'm taking a longer shot at 200-300+ I'm giving myself plenty of time to get prone and VERY steady, allowing extra time to take everything else into consideration such as wind, angle, bullet drop, allowing time for animal to stop broadside, etc, and adding a couple more inches by being sighted in at 100 is NOT a big deal.
I now stick with zero @ 100 for everything, all the time - seems to work better for me and have my stepson (newer hunter) learning to do the same. We practice often, out at least once or twice a month always shooting at 50, 100, 200+, and just yesterday we set up targets at 500!! Regardless of where you sight in, it's important to practice often and at different distances and learn exactly what to expect at each, and memorize your ballistics based on the range you decide to sight in at.
It frustrates me to no end getting to elk camp and hearing all the guys who go out once a year a few weeks before opening day firing a few shots using a sled from the bench at a hundred yards and calling it good because they dont want to practice any more with thier super-duper hard kicking magnums!
