Factory Loads: Do They Perform Better At Higher Elevations Or Lower?

Ballistics Under Pressure

When hunting at higher elevations, factory loads may struggle to deliver optimal performance due to lower air pressure. This can lead to reduced ballistic coefficient, decreased range, and lower terminal velocity. For example, a 308 Winchester load that operates at 28.2 inches of mercury (inHg) at sea level may only deliver 26.5 inHg at 8,000 feet, resulting in a 5.7% decrease in performance.

Load Selection and Preparation

To mitigate this issue, hunters can select loads specifically designed for high-altitude hunting. These loads often feature lighter bullets or specialized propellants that maintain their ballistic performance at lower air pressures. For instance, a 308 Winchester load with a 150-grain bullet may be more suitable for high-altitude hunting than a 185-grain load. Additionally, hunters can also consult load tables and consult with manufacturers to determine the best load for their specific needs. This ensures that they are using the most effective load for the job, regardless of the location.

Pressure and Performance

It’s essential to note that some factory loads are designed to operate within a specific pressure range. If a load is designed to operate at 55,000 pounds per square inch (PSI) at sea level, it may not perform optimally at higher elevations where the air pressure is lower. In such cases, hunters may need to select a load with a lower PSI rating to ensure optimal performance. By understanding the relationship between air pressure and load performance, hunters can make informed decisions about which loads to use in different environments.