Ballistics reference
Wind Drift Chart
Quick answer
A 10 mph full value crosswind pushes a .308 Winchester 168 grain match load about 7.48 inches off target at 300 yards and 22.57 inches at 500 yards, while a 6.5 Creedmoor drifts only 5.33 and 15.71 inches at the same distances because of its higher ballistic coefficient. Angle the wind off perpendicular and the true drift is smaller, following the wind clock table below.
Wind drift is the sideways push a crosswind gives a bullet over its time of flight. It depends far more on ballistic coefficient than bullet drop does, because drift accumulates with every second the bullet spends in the air rather than with distance alone: a slow, draggy bullet spends longer getting downrange and the wind has longer to act on it.
The figures below use the published lag time method, the same approximation behind most printed wind drift tables: drift equals wind speed multiplied by the difference between the bullet's actual time of flight and the time a bullet that never slowed down would have taken. It is the standard, honest approximation rather than a full three dimensional wind model, and it has a known limitation stated plainly further down this page.
Ballistic coefficient and muzzle velocity are each load's published catalogue figure. This site does not recommend or link ammunition; the cartridges are named only so the reader knows exactly what each row assumes.
How far does a 10 mph crosswind push each cartridge?
Full value means the wind is blowing at 90 degrees to the line of fire, the worst case for drift. Drift in inches, computed from each load's published ballistic coefficient and muzzle velocity through the lag time model, zeroed at 200 yards.
At 500 yards in a 10 mph full value wind, a .308 Winchester 168 grain match load drifts 22.57 inches while a 6.5 Creedmoor 140 grain match load drifts 15.71 inches over the identical wind and distance.
Sourced figure
| Cartridge | 200 yd | 300 yd | 400 yd | 500 yd | 600 yd | 800 yd |
|---|---|---|---|---|---|---|
| .22 LR | 20.85 in | 43.36 in | 73.29 in | 111.08 in | 157.41 in | 279.78 in |
| .223 Remington | 4.89 in | 11.80 in | 22.65 in | 38.41 in | 60.08 in | 122.05 in |
| 6mm ARC | 2.59 in | 6.01 in | 11.05 in | 17.87 in | 26.67 in | 51.05 in |
| .243 Winchester | 3.15 in | 7.38 in | 13.71 in | 22.44 in | 33.90 in | 66.54 in |
| 6.5 Creedmoor | 2.30 in | 5.33 in | 9.75 in | 15.71 in | 23.34 in | 44.25 in |
| .270 Winchester | 2.79 in | 6.50 in | 12.02 in | 19.57 in | 29.43 in | 57.30 in |
| 7mm Remington Magnum | 2.37 in | 5.49 in | 10.08 in | 16.28 in | 24.28 in | 46.43 in |
| .308 Winchester | 3.20 in | 7.48 in | 13.85 in | 22.57 in | 33.92 in | 65.66 in |
| .30-06 Springfield | 2.82 in | 6.56 in | 12.10 in | 19.62 in | 29.36 in | 56.45 in |
| .300 Winchester Magnum | 2.41 in | 5.60 in | 10.29 in | 16.62 in | 24.79 in | 47.42 in |
| .30-30 Winchester | 8.19 in | 19.80 in | 37.48 in | 61.12 in | 89.69 in | 158.87 in |
| .45-70 Government | 10.97 in | 23.59 in | 39.99 in | 59.83 in | 82.97 in | 139.04 in |
| .350 Legend | 10.16 in | 24.59 in | 45.94 in | 73.09 in | 104.95 in | 181.29 in |
Computed with the published lag time approximation, which is well documented as running roughly 10 percent optimistic (showing somewhat less drift than a bullet actually experiences) past about 600 yards, because it does not model the bullet's yaw and spin drift interacting with a long crosswind exposure. Treat the 800 yard column as a useful estimate rather than a precise figure.
What is the wind clock and how much does an angled wind actually cost?
Wind rarely blows exactly perpendicular to the shot. Shooters describe wind direction using a clock face, with 12 o'clock straight ahead down the line of fire and 3 or 9 o'clock directly crosswise. The value below is the fraction of the wind's full speed that actually acts as crosswind at each clock position, and it is exact trigonometry: the sine of the angle between the wind direction and the line of fire.
A full value wind at 3 or 9 o'clock counts at 1.0 times its speed, a wind at 2, 4, 8 or 10 o'clock counts at 0.87 times its speed, and a wind at 1, 5, 7 or 11 o'clock counts at 0.5 times its speed.
Shooter convention
| Clock position | Angle off the line of fire | Crosswind value | Effective speed of a 10 mph wind |
|---|---|---|---|
| 12 or 6 o'clock | 0 degrees, headwind or tailwind | 0.0 | 0.0 mph |
| 1, 5, 7 or 11 o'clock | 30 degrees | 0.5 | 5.0 mph |
| 2, 4, 8 or 10 o'clock | 60 degrees | 0.87 | 8.7 mph |
| 3 or 9 o'clock | 90 degrees, full value | 1.0 | 10.0 mph |
The multiplier itself is exact, the sine of the angle off the line of fire. What is convention is quantizing a real, gusting wind into a clean clock position at all: field wind rarely sits exactly on one of these four values, and reading it is closer to judgment than measurement.
Why does a higher ballistic coefficient matter more for wind than for drop?
Drop is mostly a function of how long gravity has to act, which is set by time of flight and is fairly similar for two loads with comparable velocity even at different ballistic coefficients. Drift compounds with the same time of flight, but a low ballistic coefficient bullet also slows down faster, which stretches its time of flight further still. The two effects reinforce each other, which is why the 6.5 Creedmoor's drift advantage over the .308 Winchester in the table above (15.71 inches against 22.57 inches at 500 yards) is proportionally larger than its drop advantage at the same distance.
How do I actually read wind in the field?
Range and wind speed are the two inputs this whole page depends on, and both are estimated far more often than measured. A laser rangefinder such as the Vortex Viper HD 3000 Laser Rangefinder removes the range guess entirely, which matters because a wind hold computed for the wrong distance is wrong twice over. Wind speed itself is read from mirage, vegetation and flags, a skill that takes practice and is covered step by step on the how to read wind for shooting guide.
Sources
- Lag time wind drift approximation, the standard method behind published wind drift tables
- Published factory load specifications: muzzle velocity and G1 ballistic coefficient for each cartridge listed
- Exact trigonometric sine values for the wind clock multipliers
Frequently asked questions
How much does 10 mph of wind push a bullet at 500 yards?
It depends entirely on the load. A .308 Winchester 168 grain match bullet drifts about 22.57 inches in a full value 10 mph wind at 500 yards, while a higher ballistic coefficient 6.5 Creedmoor 140 grain match load drifts only about 15.71 inches in the identical wind. Ballistic coefficient, not caliber, decides most of the difference between two loads.
What does "full value" wind mean?
A wind blowing at exactly 90 degrees to the line of fire, from 3 or 9 o'clock on the wind clock. It produces the maximum possible drift for a given wind speed. Any other angle produces less drift, scaled by the sine of the angle off the line of fire, which the wind clock table above gives directly for the common clock positions.
Is the wind clock's 0.5 and 0.87 exact?
The multipliers themselves are exact trigonometry, the sine of 30 and 60 degrees. What is not exact is treating a real, gusting field wind as sitting precisely on one of those clean angles. The clock is a useful mental shortcut for a genuinely messy input, not a measurement instrument, and it should be read that way.
Why does wind drift use a different method than bullet drop?
Drop comes directly from integrating the trajectory. Drift is added afterward using the published lag time method: wind speed multiplied by how much longer the real bullet took to arrive than a bullet that never slowed down would have. It is the standard approximation behind most printed wind charts, and it is honest about being an approximation rather than a full simulation.
Why does this chart say it runs optimistic past 600 yards?
The lag time method does not account for the bullet's yaw and spin drift interacting with a long crosswind exposure, an effect that grows with time of flight. Published discussion of the method generally puts the resulting gap at around 10 percent past 600 yards, meaning the true drift is somewhat more than the table shows, not less.
Does a rangefinder help with wind calls?
Indirectly but significantly. Wind drift scales with time of flight, which depends on the actual distance to the target, so an accurate range makes the wind hold that follows it accurate too. A rangefinder removes the distance guess; reading wind speed and angle correctly is still a separate skill that has to be learned and practiced.
Researched, not professional advice. This page is compiled from published manufacturer specifications, published optical and ballistic formulas, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are shooter convention rather than sourced numbers, and they are labelled that way wherever they appear. Ballistic figures come from a point mass model using the ballistic coefficient the maker publishes, so treat them as a starting point and confirm them on paper at a measured distance. Confirm your firearm is unloaded with the action open before you mount, level, torque or bore sight anything. Verify a zero only on a supervised range or a safe, legal backstop, know what lies beyond your target, and follow the law where you hunt and shoot, including rules on land access and permitted cartridges.