Wind can deflect a bullet 1-4 inches at 100 yards, depending on velocity, bullet weight, and crosswind speed
A 10 mph crosswind shifts a typical .223/5.56mm bullet ~2 inches at 100 yards, while heavier .308/7.62mm rounds drift ~1 inch. Wind impact scales with bullet flight time, profile, and wind speed. Even mild breezes demand compensation for precision shooting.
Key Factors Influencing Wind Drift
- Bullet velocity: Faster rounds (e.g., 3,000+ fps) spend less time in wind, reducing drift.
- Bullet weight/ballistic coefficient (BC): Higher BC (e.g., 0.5+) resists wind better than low-BC (e.g., 0.2) bullets.
- Wind angle: 90° (full crosswind) causes max drift; 45° reduces effect by ~70%.
- Wind speed: Drift doubles as speed doubles (e.g., 5 mph → 1", 10 mph → 2").
- Distance: Drift increases exponentially; 100-yard drift is ~1/10 of 1,000-yard drift.
Wind Drift Comparison at 100 Yards (10 mph Crosswind)
| Bullet Type | Weight (gr) | Muzzle Velocity (fps) | BC (G1) | Estimated Drift (inches) |
|---|---|---|---|---|
| .22 LR | 40 | 1,200 | 0.125 | 3.8-4.5 |
| .223 Rem / 5.56 NATO | 55 | 3,200 | 0.250 | 1.8-2.2 |
| .308 Win / 7.62 NATO | 168 | 2,700 | 0.450 | 0.9-1.2 |
| 6.5 Creedmoor | 140 | 2,800 | 0.550 | 0.7-0.9 |
How to Compensate for Wind at 100 Yards
- Estimate wind speed: Use flags, vegetation, or a wind meter. Rule of thumb:
- 3-5 mph: Leaves rustle lightly.
- 8-12 mph: Flags extend fully.
- 15+ mph: Small branches sway.
- Determine wind value: Divide speed by 10 for MOA adjustment (e.g., 10 mph = 1 MOA).
- Hold off or dial:
- Hold-off: Aim into the wind (e.g., 2" left for 10 mph right crosswind with a .223).
- Dial scope: Adjust windage turret (1 MOA = ~1" at 100 yards).
- Shoot during lulls: Wind gusts vary; fire when speed drops for tighter groups.
Common Wind Reading Mistakes
- Ignoring mirage: Heat waves distort wind reading; prioritize flags or electronic tools.
- Overcorrecting: At 100 yards, adjustments are subtle-1-2 MOA max for most winds.
- Assuming constant wind: Wind shifts direction/speed; recheck between shots.
- Neglecting bullet drop: Wind affects vertical plane slightly; focus on horizontal first.
Tools to Measure Wind Effectively
- Wind flags: Lightweight fabric flags show direction/speed at the range.
- Anemometers: Handheld devices give precise mph readings.
- Ballistic apps: Input wind data for real-time drift calculations (e.g., 10 mph = 1.8" for .223).
- Spotter feedback: Observe bullet trace or splash for post-shot corrections.