This all assumes that your scope 'clicks' are as advertised... many are not exactly 1/4 or 1/8 MOA, which can confound the above techniques.
Take your gun, at 100yds, and shoot a group. Dial on 5 minutes of elevation, and shoot another. Should be (shooter ability allowing) centered exactly 5" above the center of the first group. If it's not, say it's 6" (like my Sightrons) for 1/8 moa clicks, then it works out to abut 0.150" per click at 100yds instead of 0.125 (1/8"). Then you get to futz around generating click charts for various ranges, since you can't just dial on 9 'minutes' as indicated on the turret, as it would _really_ be more like 10.8 minutes (9 'minutes' * 8 clicks per minute * 0.150 MOA click per minute)... PITA, to say the least. *Very* important to determine what your 'true' click values are before going any further.
Monte