Why must ammunition be stored in a vented container?

Storing ammunition in a vented container is critical for reducing the risk of an explosive hazard during a fire. In the event of a fire, ammunition can heat up and potentially cook off, meaning the primer ignites and causes the round to fire. A vented container allows the heat and pressure to escape safely, minimizing the risk of the container bursting and creating shrapnel, or the ammunition itself cooking off in a dangerous manner.

Other options relate to convenience or appearance, but they do not address the safety implications associated with temperature changes and combustion. A vented design is specifically engineered to prioritize safety in hazardous situations, making it essential for the secure storage of firearms and ammunition.