READING THE WIND

Whatever your load, hitting at distance hinges on your ability to read wind, then predict its effect. Alpine slopes often deny you a look at moving leaves and grass. Drifting snow is a sometime thing. Ditto dust. A pinch of talcum powder from a squeezebulb can help you sneak close to a ram; but the feathery currents that might carry your scent to nearby game have no effect on bullets sent out yonder.

Boat-tail or tapered-heel bullets offer little advantage in wind at normal hunting ranges: Started at 2,700 fps, flat-base 140-grain 7mm bullets cover 100 yards as fast as boat-tail 140s. At 200, the flat-base clocks 2,305 fps, the boat-tail bullet 2,320. At 350 yards, the boat-tail bullet leads by 35 fps. Difference in drop is only half an inch. Ditto for drift in a 10-mph wind. A because the bullet’s form and speed enter as variables.

Calculating drift can leave you scrambling, mentally, when a ram is making its way into oblivion over yon ridge. Better to immerse yourself in atmospheric rivers early. After zeroing in calm air, leave the bench and humble yourself on windy days, watching bullets bend to the blow. WS

Mirage is your friend. Visible as heat waves rising from the earth, mirage reveals the speed and direction of moving air. It’s essentially absent on cold, dark days, and not easily seen through low-power optics. Slow, bumpy mirage indicates a light breeze. Flat, fast mirage is chased by brisk wind. Mirage that vanishes with no change in light conditions often belies a strong blow. Mirage that boils vertically signals a still condition. A lull in strong wind can be your chance to fire; but beware. A boil in mirage commonly precedes a pick-up, or a reversal in wind direction.

Mirage shows up best at the distance an optic is focused. Moving your binocular or rifle-scope to see different backgrounds, you may well find one shows mirage better than the rest.

Deviously, mirage can show you what isn’t there, “floating” an image from its true position in the direction air currents are moving. WS