Open a trace and load or enter the parameters for the ammo you are shooting, the range you are currently zeroed at, and the conditions that existed when you zeroed. Of these conditions the most important are altitude and temperature. It's OK if you don't know all this, just remember the more accurate the input is the more accurate the output will be.

In this example we have a factory 30-06 load zeroed at 100 yards and we would like to change the zeroed range to 150 yards. We are using a scope with the usual 1.5 inch (line of sight to center of bore) height, which is set in the Sight Height parameter...