At what temperature can 6.5-284 Norma performance degrade?

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Temperature Effects on Ballistics The 6.5-284 Norma, a popular cartridge among long-range shooters, exhibits noticeable temperature-related performance degradation. At temperatures between 90°F (32°C) and 100°F (38°C), you can expect a 5-10% reduction in bullet velocity and a corresponding decrease in kinetic energy. This translates to slightly reduced long-range accuracy and increased bullet drop.
Temperature-Related Accuracy Issues To understand the impact of temperature on accuracy, consider the following: a 10°F (5.6°C) increase in temperature can cause a 1-2 MOA shift in bullet trajectory. For example, at 100 yards, a 10°F (5.6°C) temperature increase can result in a 1-2 inch bullet shift. This may not seem significant, but at extended ranges (beyond 500 yards), temperature-related accuracy issues can become a critical consideration.
Ballistic Coefficient and Temperature Sensitivity The 6.5-284 Norma’s ballistic coefficient (BC) plays a significant role in determining its temperature sensitivity. The BC measures a bullet’s aerodynamic efficiency, with lower BCs indicating greater temperature sensitivity. By selecting a bullet with a lower BC, you can mitigate temperature-related accuracy issues, but this often comes at the cost of reduced kinetic energy and range. A compromise must be struck between BC and kinetic energy, taking into account the specific application and environmental conditions.