What should be observed when squeezing and releasing the trigger during the function check?

During the function check of an M9 Service Pistol, observing that the firing pin block moves is crucial for confirming the proper operation of the safety mechanism in the firearm. The firing pin block is designed to prevent the firing pin from moving forward unless the trigger is fully pulled. This means that when squeezing and releasing the trigger, the movement of the firing pin block indicates that the safety feature is functioning as intended. If the firing pin block does not move, it could suggest a malfunction in the safety mechanism, which can lead to unsafe conditions if the firearm is handled incorrectly.

The observation of the firing pin block moving is significant because it validates that the firearm is capable of preventing accidental discharges, enhancing overall safety. Proper function of this component is an essential aspect of a reliable firearm, as it ensures that no unintended discharge occurs when the trigger is not fully activated. A thorough understanding of this aspect of the function check helps ensure the operator is aware of the weapon's safety features and is crucial for maintaining safe and responsible handling of the pistol.