What does prolonged exposure to heat do to ammunition?

Prolonged exposure to heat can cause a significant degradation of ammunition effectiveness. High temperatures can lead to chemical changes within the propellant, potentially causing it to become less stable and unreliable. This might result in reduced velocity, poor ignition, or even misfires. Furthermore, heat can adversely affect the integrity of components like primers and casing materials, contributing to safety hazards and compromising overall performance.

While some options suggest changes that may occur due to heat exposure, none inherently lead to improved ammunition performance, making the option that states it becomes less effective the most accurate in portraying the impact of excessive heat on ammunition reliability.