What environmental factors influence bullet performance in .458 Lott?

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Atmospheric Conditions Atmospheric conditions play a crucial role in determining bullet performance. Temperature is a critical factor, as it affects the expansion of gases behind the bullet. A 10°F increase in temperature can result in a 0.3% increase in bullet velocity. Conversely, a 10°F decrease in temperature can result in a 0.4% decrease in bullet velocity. For example, a .458 Lott bullet fired at 70°F (21°C) might achieve a velocity of 2,200 ft/s, but at 50°F (10°C), it might lose 70 ft/s, resulting in a velocity of 2,130 ft/s.
Humidity and Air Pressure Humidity and air pressure are also significant factors that can affect bullet performance. In humid environments, the air is more dense, which can reduce bullet velocity. For instance, a .458 Lott bullet fired at 80% humidity might lose 50 ft/s compared to firing in dry conditions. Similarly, changes in air pressure can affect the bullet’s trajectory. A 10-inch Hg decrease in air pressure can result in a 2-inch increase in bullet drop at 500 yards.
Wind Resistance Wind resistance is another critical factor that can affect bullet performance. The wind can deflect the bullet, resulting in a loss of accuracy and penetration. In strong winds, it is essential to adjust the bullet’s trajectory accordingly. For example, in a 20-mph crosswind, a .458 Lott bullet fired at 500 yards might be deflected by 10 inches. To compensate for this, hunters can adjust their aim by 5-7 inches, depending on the wind direction and bullet characteristics.