Lock time

A firing pin and firing pin spring, whose design can greatly affect the lock time of a firearm.

Lock time or action time refers to the time interval (often measured in milliseconds) from when the trigger of a firearm is activated until the firing pin strikes the primer, and depends on the design of the firing mechanism. A long lock time increases the probability of the shooter pulling the sights away from the target before the bullet has left the barrel, a common shooter error which can lead to poor hits or even misses. Shooters can therefore tend to experience better precision using firearms with a shorter lock time, and short lock times are especially sought after for shooting competitions which require high precision on small targets from unstable positions, such as the standing offhand position.