More than once I’ve heard a shooter mutter, “WTF?” (not the PG-13 version), after missing a shot at the range. This is backward, however. We should say “WTF” before pulling the trigger. It’s what my friend Frank Galli, a former Marine scout sniper and shooting instructor, teaches his students. Short for “wind, trajectory, and fundamentals,” it is the mental checklist to use when prepping for a shot. Wind comes first because it’s by far the trickiest.
Rule of Thirds
Start by dividing the wind into three segments: at the muzzle, midway between muzzle and target, and at the target. Any wind at the muzzle will push the bullet in that direction for its entire flight. In the middle, the bullet is at its maximum height, where wind speeds tend to be greater, so you may need to account for a faster wind gradient. Near the target, the bullet is slowing down, and wind will push it around more easily.
Measuring wind speed and direction at your location is the easiest. A handheld wind meter, which can be had for less than $20, is a vital tool. Direction can be determined with a piece of flagging tape, a wind checker, or the hygienically questionable standby, licking your finger.
Determining wind speed at the other two distances requires observation. The classic rule of thumb says a 5 to 8 mph wind gently moves leaves and grass; at 8 to 12 mph, dust gets kicked up; from 12 to 15 mph, smaller trees will sway; and at higher speeds, water will show whitecaps. This is a useful guide, but it comes with an important caveat. It takes more to push around trees and bushes growing in windswept regions, like the Great Plains and Rocky Mountains, than it does the broad-leafed oaks of the East and Midwest. So your mental map of how wind affects the environment needs to be calibrated to the terrain.
If the wind appears consistent in each of the three segments, use the value taken at the shooting position. If not, bump the value up or down depending on what you see at the middle and longer distances.
On the Clock
Figuring out wind direction downrange is tough, but if there’s any mirage you’re in luck. I learned this trick from Emil Praslick, one of the best wind callers in the world of long-range shooting. Using your binocular or spotting scope, pivot until the mirage boils straight up and down. On that vector, the wind is either heading straight toward you or straight away. Compare that to the direction of the shot, and you’ve established the angle of the wind relative to the bullet’s flight.
Now, what percentage of that wind speed do you use in your calculations? If the wind is blowing directly toward (12 o’clock) or away from the target (6 o’clock), the answer is zero—the wind will have no effect on the bullet. A crosswind (3 or 9 o’clock) uses 100 percent of the value. But what about wind angling somewhere between these points?
The solution is somewhat nonintuitive. The biggest mistake is to think that a 45-degree wind (coming from 1:30, 4:30, 7:30, or 10:30 on our clock face) has a 50 percent value. It doesn’t. Instead, 12 o’clock uses zero percent of the wind value; 12:30 is 25 percent; 1 o’clock is 50 percent; 1:30 is 75 percent; 2 o’clock is 90 percent; and anything from 2:30 to 3 is 100 percent. So, if you have a 10 mph wind coming from 12:30, calculate your windage based on a 2.5 mph wind. A 1:30 wind at 10 mph uses a value of 7.5 mph, and so on.
This relationship between wind angle and wind value remains valid at all points on the clock face. Any wind between 8:30 and 9:30 and 2:30 and 3:30 is 100 percent. Winds at 12:30, 11:30, 5:30, and 6:30 are all 25 percent, etc. I keep a drawing of this wind rose with my dope card at all times for reference.
Next you need to figure out the speed of your rifle. Use an online ballistics calculator for this. Both Federal and Hornady have good ones. If you shoot in mils, find the 90-degree crosswind that causes your bullet to drift .6 mils at 600 yards. In the case of my 6mm Creedmoor shooting a 108-grain ELD-M at 2960 fps, that’s a 5 mph wind, meaning I have a 5 mph gun. At 500 yards, the bullet drifts .5 mils; at 400 yards, .4 mils; 300 yards, .3 mils, and so on. With this simple 1:1 relationship, I can figure out my wind hold in a flash. At 10 mph, these values double. At 2.5 mph they’re halved.
For MOA shooters, the drill is similar, except you find the wind hold for a 3 MOA drift at 600 yards. When you run the numbers for your rifle, you’ll have to round up or down a touch, but don’t sweat it. Make a chart and tape this to your stock, too.
Once you get beyond 600 yards, the wind holds increase and the 1:1 relationship doesn’t hold. But the calculations are still pretty simple. Going back to the 6 Creed, at 700, I have a .7 mil hold at 5 mph; at 800 and 900, I add an extra .1 (.9 and 1 mil, respectively); and at 1,000 I add an extra .2 for a 1.2 mil hold at 5 mph.
Keep this data on hand, practice observing the wind, and you’ll find yourself saying “WTF” before the shot instead of after.