I was wondering how you guys used your SFP NP-R1 for holdovers-unders at different powers. Mine is the 3.5-15 with each hash mark being 1moa on elevation and 2moa on wind at 15 power. Now, you would think they would have a 7.5X mark that would easily double each mark from 1-2 and 2-4, Correct?? I'm just wondering if anyone has come-up with a simple formula for changing magnifications. Thanks