What happens when the decocking/safety lever is moved to the down position?

When the decocking/safety lever is moved to the down position, it safely lowers the hammer of the pistol without discharging the weapon. This function is crucial because it allows the shooter to safely carry the M9 Service Pistol while ensuring that the firearm is not in a cocked and ready-to-fire state. As the hammer is released in this manner, it significantly minimizes the risk of unintentional discharges, making it a critical safety feature for handling the weapon. Being able to decock the hammer while maintaining control of the firearm is essential for safe firearm practices within military and law enforcement protocols.

The other choices do not accurately reflect the function of the decocking/safety lever; the lever does not transform the weapon into a fully automatic firearm, nor does it lock the slide in place or render the trigger unresponsive. Understanding the operation of the decocking/safety lever is fundamental for anyone training with the M9 Service Pistol, as it directly impacts safety and handling procedures.