The problem is each sheet is only good for those conditions and the particular zoom setting. When you change magnification, the ranges change. If you go up or down in elevation, the ranges change. If the temp outside changes, the ranges change. So a guy either becomes dependent upon carrying a mobile device and rerunning the parameters, or he carries a DOPE book full of read-out prints and has to match up his current conditions with their respective ranges for the reticle markings.

Or a guy buys a proper ranging reticle scope with regular intervals between markings and simply has to record how his load responds at different temps and elevations, or remember a rule of thumb for temp and elevation effects.