Calculating the proper elevation and windage adjustments necessary to score an accurate follow up shot is one of the most basic calculations you need to understand in order to be able to score good hits in any type of scored or real life scenario. Although these adjustments are generally second nature for many shooters, I came a cross what I thought was a simple and easy to remember expression that can help a shooter of any level but especially new shooters quickly determine their site changes at variosu disctances.
Credit belongs to both Retired Nay SEAL Master Chief Jim Kauber, and Gunsite Grad Frank Zaruger and the expression is called
The Doctor is In ...
CORRECTION (in inches)
––––––––––––––––- = MOA CHANGE
DISTANCE (in hundreds of yards)
Instead of dealing with three different expressions for each of the three variables.
M * D
IN = Inches of change on target
M = Minutes of Angle
D = Distance in hundreds of yards
To use Frank's method, just place your fingertip over the factor you want to
determine, which tells you to multiply or divide the other two factors, to learn the
third factor. Let's say you want to see how many inches 5 MOAs are at 200
yards: Just place a fingertip over "IN" and you see that you must multiply the
MOAs by the Distance, which means 5 MOAs times 2 (Distance in hundreds of
yards). Therefore, the answer is 10 inches. And if you're trying to determine how
many MOAs to crank your scope when you want to raise the bullet impact ten
inches at 200 yards: put a fingertip on the "M" (for MOA), and you see you must
divide the inches by the distance. Frank's graphic formula is simple and easy to