Understanding bullet drop is crucial for accurate long-range shooting. This guide provides a detailed bullet drop chart for the popular .308 Winchester caliber using 168-grain bullets, along with explanations to help you interpret and utilize this data effectively. We’ll also explore factors influencing bullet drop and how to adjust for optimal accuracy.
Understanding Bullet Drop
Bullet drop refers to the vertical distance a bullet falls from its initial trajectory due to gravity. Ignoring wind and other environmental factors, a bullet fired horizontally will immediately begin to arc downwards. The heavier the bullet and the faster its muzzle velocity, the less pronounced the drop will be at shorter ranges. However, at longer ranges, bullet drop becomes a significant factor that needs to be accounted for to achieve accurate shots.
Factors Affecting Bullet Drop
Several factors beyond gravity influence bullet drop:
- Muzzle Velocity: A higher muzzle velocity translates to less bullet drop at any given range.
- Bullet Weight: Heavier bullets generally experience less drop than lighter bullets fired at the same velocity. The 168-grain bullet is a popular choice for its balance of velocity and ballistic coefficient.
- Ballistic Coefficient (BC): BC measures a bullet's aerodynamic efficiency. A higher BC means less drop and drift due to improved air resistance.
- Altitude: Higher altitudes result in decreased air density, leading to less bullet drop.
- Temperature: Higher temperatures generally decrease air density, similarly affecting bullet drop.
- Wind: Wind significantly impacts bullet trajectory, causing both horizontal and vertical drift. This is a critical factor for long-range shooting.
- Barrel Twist Rate: The rifling twist rate affects bullet stability, which indirectly impacts bullet drop. A properly matched twist rate ensures optimal accuracy.
Sample Bullet Drop Chart: 308 Winchester 168 Grain Bullet (Approximate Values)
Disclaimer: The following chart provides approximate values. Actual bullet drop can vary depending on the specific ammunition, rifle, environmental conditions, and other factors. Always use a ballistic calculator with your specific ammunition data for precise calculations.
| Range (yards) | Drop (inches) |
|---|---|
| 100 | 2 |
| 200 | 8 |
| 300 | 18 |
| 400 | 32 |
| 500 | 50 |
| 600 | 72 |
| 700 | 98 |
| 800 | 128 |
| 900 | 162 |
| 1000 | 200 |
Note: This chart assumes standard atmospheric conditions (sea level, 59°F, no wind). Windage is not included.
Utilizing the Bullet Drop Chart
The chart provides a visual representation of how much your bullet will drop at different ranges. To compensate for bullet drop, you need to aim higher than the target. This is typically done by adjusting your scope's elevation turret.
Using a Ballistic Calculator
For accurate long-range shooting, using a ballistic calculator is strongly recommended. These calculators account for various environmental factors and your specific ammunition data to provide highly accurate drop calculations. Many free and paid ballistic calculators are available online and through dedicated ballistics apps.
Conclusion
Understanding bullet drop is fundamental to accurate long-range shooting with a .308 Winchester and 168-grain bullets. While this chart provides a useful reference, always remember that environmental factors significantly influence bullet trajectory. Using a ballistic calculator and practicing on the range are essential for mastering long-range shooting. Remember to always prioritize safety and follow responsible firearm handling practices.
