What is a fundamental rule when handling firearms?

The fundamental rule when handling firearms emphasizes the importance of keeping your finger off the trigger until you are prepared to shoot. This rule is vital for ensuring that unintentional discharges do not occur. By keeping your finger outside the trigger guard, you maintain better control over the firearm and significantly reduce the risk of an accidental firing. This practice is essential whether the firearm is loaded or unloaded since it cultivates a habit that enhances overall safety at all times.

The other options do not embody this critical safety principle. Keeping the firearm unloaded is a good practice but does not account for the situations where firearms need to be loaded for use. Showing off a firearm undermines safety by promoting irresponsible handling and could lead to dangerous situations. Lastly, cleaning a firearm only when it jams neglects the importance of regular maintenance and inspection to ensure the firearm functions correctly and safely at all times.