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Headwind, Tailwind and Aerodynamic Jump: The Vertical Part of the Wind

A 10 mph headwind barely moves a 6.5 Creedmoor at 1,000 yards. A 10 mph crosswind moves it vertically more. How much head and tail winds change elevation, how crosswind jump works, and which way it goes.

6 min readSolved with the Ballista engineUpdated October 2026

Shoot a 6.5 Creedmoor at 1,000 yards into a 10 mph headwind and it needs 0.06 mil more elevation than in still air. Turn the same wind 90° so it blows across the range, and the vertical change is 0.10 mil. For this rifle, a crosswind moves the impact up or down more than a headwind does at every range out to 1,000 yards. The vertical part of the wind comes mostly from the side.

Headwinds and tailwinds: small, and growing late

A headwind adds its speed to the speed of the bullet through the air. Ten miles per hour is 14.7 fps, small next to a 6.5 bullet that leaves at 2,710 fps and still travels 1,485 fps at 1,000 yd. The bullet feels slightly more drag, slows slightly sooner and spends slightly longer falling. A tailwind does the reverse.

Out to 700 yd neither rifle needs as much as a tenth of a mil, even at 20 mph. Head and tail winds are also symmetric: in this solution a tailwind takes away the same elevation a headwind adds, to within 0.02 mil.

A useful way to size it: at 1,000 yd, a 10 mph headwind has the same effect on elevation as muzzle velocity about 8 fps lower for the 6.5 and 13 fps lower for the .308. The muzzle velocity versus BC article shows what that kind of velocity error does further out.

So the field rule is simple. Ignore head and tail winds inside about 700 yd. Past that, a strong one is worth a click with a lower-BC bullet. A quartering wind carries both a crosswind and a head or tail part; the wind angles article splits them.

Aerodynamic jump: why a crosswind moves the impact vertically

A spinning bullet that leaves the muzzle into a crosswind meets air coming slightly from the side. Its nose yaws toward the relative wind. A spinning bullet doesn’t simply swing back; its yaw circles around the flight path while it settles, and that circling motion near the muzzle leaves the bullet on a slightly different vertical angle. The angle then stays the same for the whole flight. McCoy covers the theory of aerodynamic jump; Litz measured it for long-range bullets and published a simple model.

The Ballista engine uses that model:

jump (MOA) = (0.01 × Sg − 0.0024 × length in calibers + 0.032) × crosswind (mph)

Sg is the gyroscopic stability factor. For the 6.5 it is 1.63 and the bullet is 5.26 calibers long, so the formula gives 0.0357 MOA per mph, or 0.104 mil at 10 mph. The .308, with Sg 2.40, gets 0.135 mil. Those are the dashed lines in the chart. Run the same crosswind with jump switched off and elevation doesn’t change to the thousandth of a mil, so the vertical effect of a crosswind is all jump.

Because jump is a constant angle (the engine’s value varies by less than 0.001 mil from 100 to 1,000 yd), it grows in inches in a straight line with distance: 0.37 in at 100 yd and 3.7 in at 1,000 for the 6.5.

Which way it goes

The direction depends on two things: the side the wind comes from and the barrel’s twist.

With right-hand twist, as on both reference rifles, wind from the right moves impacts down and wind from the left moves them up. A left-hand barrel reverses both. The size is set by the crosswind component, so a quartering wind gives the matching fraction.

Where jump shows up: short range and stringing

Jump looks trivial at 1,000 yd, where it’s a few inches next to many feet of drift. At short range the comparison flips.

At 100 yd a 10 mph crosswind moves the 6.5 71% as far vertically as horizontally. In a gusting crosswind, groups at short range string on a diagonal: with right-hand twist and wind from the right, harder gusts throw shots left and low, lulls right and high. Benchrest and zeroing sessions are where this bites. A vertical string on a windy 100 yd zero day may be wind, not the rifle or the shooter.

The zero itself can carry it too. Zero a 6.5 at 100 yd in a steady 10 mph wind from the right and you correct for 0.37 in of jump that won’t be there on a calm day. That’s 0.10 mil of elevation built into your zero, about 3.7 in high at 1,000 yd once the wind drops. Zero in calm air, or with the wind straight down the range.

What the app shows

Ballista includes jump in the elevation answer whenever there is a crosswind and the profile has the bullet’s length and the barrel twist. It’s on by default; the switch is “Aerodynamic jump” under Corrections in Settings. When the jump moves the answer by half a click or more, the Sources sheet (tap the elevation or wind card) explains it with a line such as “Includes wind jump: UP 0.37 MOA from the 10 mph crosswind.” Head and tail winds are not counted as jump.

In the field

1. Ignore head and tail winds for elevation inside about 700 yd. Past that, add a click for a strong headwind with a low-BC bullet, or let the solver do it.
2. Expect a crosswind to move your elevation by a fixed angle: about 0.1 mil per 10 mph for the 6.5 here, more for the .308. Down for wind from the right with right-hand twist.
3. When a group strings diagonally in a gusty crosswind, read it as wind before you blame the rifle.
4. Zero in calm air or with the wind from 12 or 6 o’clock.