Altitude & Atmospheric Pressure in Long Range Shooting

Shooting at targets placed at very long distances from the shooter.

In the world of long range shooting, understanding the effects of altitude and atmospheric pressure on bullet trajectory is crucial. These environmental factors can significantly impact the bullet's flight path and ultimately, the accuracy of your shot. This article will delve into these effects and provide guidance on how to adjust your shooting techniques accordingly.

The Effects of Altitude on Bullet Trajectory

Altitude refers to the height above sea level. As you ascend in altitude, the air becomes thinner. This thin air offers less resistance to the bullet, allowing it to travel faster and drop less than it would at lower altitudes.

For example, a shot fired at 1,000 yards at sea level will drop more than the same shot fired at 1,000 yards in a high-altitude environment. This is because the bullet at higher altitude encounters less air resistance, allowing it to maintain a higher velocity for a longer distance.

The Impact of Atmospheric Pressure

Atmospheric pressure, often referred to as barometric pressure, is the force exerted by the weight of the atmosphere. It decreases as you ascend in altitude. Lower atmospheric pressure means less air resistance, similar to the effects of altitude.

Changes in weather can also affect atmospheric pressure. High-pressure systems often bring clear skies and calm weather, while low-pressure systems are associated with stormy weather. A drop in atmospheric pressure, whether due to altitude or weather changes, will result in less bullet drop.

Adjusting for Altitude and Atmospheric Pressure

To adjust for altitude and atmospheric pressure, shooters often use a ballistic calculator. These calculators allow you to input various factors, including altitude and atmospheric pressure, to provide a more accurate firing solution.

However, it's also important to understand the principles behind these adjustments. When shooting at high altitudes or in low-pressure conditions, you'll need to adjust your aim point lower than you would under standard conditions. This is because the bullet will drop less due to the reduced air resistance.

Understanding Density Altitude

Density altitude is a concept that combines the effects of temperature, altitude, and atmospheric pressure into a single variable. It's essentially the altitude at which the air would have the same density under standard conditions.

In long range shooting, understanding density altitude can help simplify adjustments for environmental conditions. Many ballistic calculators include density altitude in their calculations, providing an even more accurate firing solution.

In conclusion, altitude and atmospheric pressure play a significant role in long range shooting. By understanding their effects and learning how to adjust for them, you can greatly improve your accuracy and consistency in long range shooting.