Jot down and memorize the 10 mph, full-value data, and you can do the rest in your head. Say your target is 400 yards, and the wind is 5 mph, blowing from 2 o'clock. Since 13 inches is the drift for 10 mph, halve it for 5 mph—6.5 inches—and round it to 7 inches. The wind's at 2 o'clock, so go with 3⁄4 value—about 4 inches. Therefore, you should aim 4 inches into the wind to drift your bullet to the intended point of impact. (See Step 3.)
Shoot at the Right Time
When you encounter multiple winds of varying speeds, time your shot so it's calm near you and compensate for the far wind. Similarly, if one wind is gusting and another steady, shoot between gusts, with compensation for the steady wind. Master the wind, and you may well have mastered long-range shooting.