What safety measure should be taken in case of a misfire with the M203?

In the event of a misfire with the M203, the appropriate safety measure is to wait for a specified amount of time before attempting to check or address the situation. Waiting 30 seconds is recommended because this duration allows for any lingering rounds that may have delayed ignition to potentially fire. This precaution helps ensure that a round does not accidentally discharge while the user is in a potentially dangerous position, reducing the risk of injury.

By adopting this practice, personnel maintain safety and follow proper protocols when dealing with misfires. The other choices may not provide sufficient waiting time for safety, or they suggest actions that could expose the individual to risk. Therefore, waiting 30 seconds is the most effective approach in maintaining safety during a misfire incident with the M203.