I used a Leupold 6.5x20 with the varmint reticle on my custom 7STW. I sighted the crosshairs in @ 200yds. Then I moved over to the 500 yd range and shot using the appropriate crosswire for that range. I had to adjust the magnification ring slightly to get the bullet impacts to fall exactly where I wanted them but it was pretty easy.
Two weeks later I spotted a whitetail that was walking across a dirt trail and stopped just long enough for me to get a laser reading. The deer was at 469 yds. and continued to walk across. I was able to steady my rifle and squeeze off a shot before the deer vanished into the brush. Point of impact was on the money and just in a nic of time.
Sometimes dialing up may cost you a shot opportunity. I like the multi wire reticles for some types of shooting. They are fasssst.
Zeiss has a Rapid Z 800 reticle that will take you out to 800 yds. They have a ballistic calculator on their web site which will show you where the magnification ring should be for various bullets and muzzle velocities. Obviously, this set-up can not account for changes in temperature, altitude, barametric pressure, etc.