yeoman, best bet is to go out and shoot in no wind and then see what happens on a windy day for a given bullet/load. I wish I had more time to do that so I play around with these calculators. Mostof my hunting will be relatively close in, less than a 100 yards, so if the calculator seems to say that a bullet will drift less than 4 inches at 10 mile sper hour wind at 100 yards, it is something I will look at to test. If it proves out then I know I'm good to go, aim and shoot, to 100 yards regardless of the weather.