Everything else in a firing solution can be measured. Distance with a rangefinder, velocity with a chronograph, pressure and temperature with a sensor, angle with a clinometer. Wind is different: it varies along the flight path, changes between the moment you read it and the moment you fire, and you can only sample it where you happen to be standing.
Clock positions, and which way they point
The clock face is the standard shorthand. You are at the centre facing the target at 12 o'clock. The hour names the direction the wind is coming FROM — the same convention a weather report uses, and the one the app uses.
| Wind from | Component | Effect on the bullet |
|---|---|---|
| 12 o'clock | Full headwind | No drift; slightly more drop |
| 3 o'clock | Full crosswind from the right | Pushes the bullet left |
| 6 o'clock | Full tailwind | No drift; slightly less drop |
| 9 o'clock | Full crosswind from the left | Pushes the bullet right |
| 1, 5, 7, 11 o'clock | Half value | Half the drift of a full crosswind |
| 2, 4, 8, 10 o'clock | About 87 per cent | Usually treated as full value in the field |
The last row surprises people. An oblique wind at 2 o'clock still carries 87 per cent of the crosswind of a full 3 o'clock wind. There is no meaningful difference between a 2 o'clock and a 3 o'clock wind for practical purposes — but there is a large difference between 1 o'clock and 2 o'clock, because that is where the cosine curve is steep.
Head and tail winds barely matter
A headwind does slow the bullet slightly and increase drop, and a tailwind does the reverse, but the magnitudes are small — typically a fraction of the effect the same wind would have as a crosswind. If you are choosing where to spend your attention, spend it on the crosswind component.
The app decomposes your clock reading into both components and applies each, so you do not have to do this arithmetic. You only have to give it an honest hour and an honest speed.
Estimating speed without a meter
| Indication | Approximate speed |
|---|---|
| Smoke drifts, you feel nothing on your face | 1–3 mph / 0.5–1.5 m/s |
| Felt on the face, leaves rustle | 3–7 mph / 1.5–3 m/s |
| Leaves and small twigs in constant motion | 8–12 mph / 3.5–5.5 m/s |
| Small branches move, dust and loose paper lift | 13–18 mph / 6–8 m/s |
| Small trees sway | 19–24 mph / 8.5–11 m/s |
A wind meter at the firing line is worth owning, but understand what it gives you: the wind at the shooter, at ground level, at one instant. It does not describe the wind at 400 m where the bullet spends the middle of its flight.
Mirage: the best instrument on the range
Heat shimmer viewed through a spotting scope moves with the air. Focus the scope short of the target — roughly two thirds of the way — and read the shimmer there rather than at the target itself.
- Boiling straight up — wind is very light or directly along the line of fire.
- Flowing steadily left or right — a crosswind; the faster the flow, the stronger it is.
- Flattened into near-horizontal streaks — around 8–12 mph; above this, mirage flattens out and stops resolving speed.
- Mirage disappears — either the wind is strong enough to break it up or the air has cooled. Fall back on vegetation.
Mirage is most useful precisely where a wind meter is least useful: out along the flight path, where you cannot stand.
Wind is not one number
The wind at your position, the wind in the dip at 300 m, and the wind on the far bank at 700 m may be three different winds. A solver takes a single value and applies it uniformly, which is a simplification you must manage.
Two working rules make it manageable. First, the wind's effect is weighted toward the early part of the flight, when the bullet is still fast and the small sideways push has the whole remaining flight time to accumulate into displacement. Second, terrain funnels wind — a valley, a treeline, a berm all change local direction, sometimes reversing it.
- Read the wind at the targetIt tells you the direction the last part of the flight sees, and it is where the miss will be scored.
- Read the wind at your positionCheap and precise, and it dominates the early flight, where drift is generated.
- Look for what disagrees between themFlags, grass, dust, mirage. A reversal halfway down means you are averaging two winds, not measuring one.
- Call the average, then favour the stronger indicatorIf you must be wrong, be wrong on the side of the wind that acts earliest.
- Note what you called and what you gotThe only way wind calling improves is by writing down the call and the actual impact, shot after shot.
What good looks like
Nobody calls wind perfectly. The realistic goal is a call that puts you inside the target on the first round and lets you correct from the splash. Shooters who hit consistently at distance are not reading wind more accurately than everyone else — they are bracketing it better, and they are correcting faster.
Structured practice helps more than theory here. The wind calling drill turns each shot into a recorded prediction, which is the only way to find out whether your estimates are biased high or low.
Frequently asked
Does the clock position mean where the wind comes from or where it goes? +
Where it comes from. Wind at 3 o'clock is blowing from your right, which pushes the bullet to the left. This matches weather reporting and it is the convention the app uses.
Why does a headwind increase drop? +
It increases the bullet's speed relative to the air, which increases drag, which means the bullet arrives later and gravity has acted for longer. The effect is real but much smaller than crosswind drift.
Should I dial wind or hold it? +
Hold it, in almost every case. Wind changes between shots and a held correction can change with it, while a dialled one has to be turned back. Dialling wind makes sense only for a long, stable, known condition.