Safety (firearms)

Some firearms manufactured after the late 1990s and early 2000s include a mandatory integral locking mechanisms that must be deactivated by a unique key before the gun can be fired.

The most common form of safety mechanism is a switch, button or lever that when set to the "safe" position, prevents the firing of a firearm.

The benefit of these design variances have not been clearly stated or pointed out by manufacturers, however, in the Ruger SR example, a chambered round cannot be ejected to empty the gun with the manual safety in the safe position.

[4] As the Ortgies is a pocket pistol meant for personal defense, this feature eliminates the problem of failing to disengage the safety when one needs to shoot.

[5] Most traditional semi-automatic double-action/single action (DA/SA) pistols are designed to be carried with the hammer down (uncocked) on a chambered round, with or without a manual safety engaged.

Striker-fired pistols, on the other hand, do not have a hammer, so the only way to return the trigger to its longer pull (safer) state is by means of a decocking or detensioning lever which actually releases the tension in the striker's spring without allowing firing pin full travel and internal safeties disengagement (such as the firing pin block which these types of firearms are generally fitted with).

That eliminates the need to pull the trigger or to control the fall of the hammer; however, since all mechanisms can fail, it is still necessary to keep the muzzle of the gun pointed in a safe direction while decocking.

A simpler "two-way" system was popularized by the Walther PP and is also commonly seen on the Beretta 92: engaging the safety also decocks the firearm.

Such safeties generally provide an obstacle to operation of the firing mechanism that is only removed when the trigger is pulled, so that the firearm cannot otherwise discharge.

However, a safety notch used to "half-cock" a firearm is an active feature that must be engaged, and does not positively prevent accidental discharges in all cases.

This prevents the firing pin from striking a chambered cartridge unless the trigger is pulled, even if the hammer is released due to a faulty sear or the gun is dropped or struck by another object.

It is a latch, block or other obstruction built into the action and normally positioned to prevent the hammer contacting the cartridge primer or firing pin when at rest.

Similar to the firing pin block, the obstruction to the hammer's travel is removed as a consequence of pulling the trigger.

Older pump-action shotguns such as the Winchester Model 12 did not have such a feature, and as a result if the trigger was held the newly chambered round would be fired as soon as the breech had been closed.

Such disconnects or interlocks are generally simple to incorporate, and in fact are a by-product of many firearms' actions; pulling the trigger while the breech is unlocked or open does nothing as the mechanism is not fully reset until cycling is complete.

Passing handguns or rifles to another person with the action open (known as "show clear") is recommended by elementary gun safety.

A Pro variant of the Ruger LC9s was introduced in December 2014, without a magazine disconnect, as a backup gun for law enforcement officers.

Such a design, made popular by Glock pistols but originally used in the 1897 Iver Johnson Second Model Safety Hammerless revolver, incorporates a trigger with a spring-loaded lever in its lower half.

Other designs include a spring-loaded pad that forms the upper portion of the trigger face and manipulates a similar lock.

Such devices have been in existence for decades;[21] strictly speaking, loaded chamber indicators are not safeties, nor are they efficacious with an untrained user.

[13] Another form of warning is an indicator behind the ejector port that does not rise enough to disrupt a shooter's sight picture, but enough to be easily seen or felt to alert a user that there is a round in the chamber.

It also prevents out-of-battery "slamfire" malfunctions that occur when a hammer follows the bolt carrier group forward as it closes.

The original designs, which dated to back before the US Civil War, had no internal safety to render them drop-safe, and were usually carried with an empty chamber under the hammer.

[22] Modern single-action revolvers, those made after the early 1970s, almost always have an internal safety, such as a hammer block or transfer bar.

[23] Most double-action revolvers have no external safety devices; a sufficiently firm trigger pull will always result in firing.

The heavy trigger pull required to cock and then fire the firearm usually prevents accidental discharges due to dropping or mishandling the gun.

Most modern double-action revolvers have an internal safety, either a hammer block or a transfer bar, that positively prevents firing without the trigger being pulled.

The only modern double-action revolvers with external safeties are unusual cases available only on special order or modified through aftermarket conversions.

The Winchester Model 94 originally utilized a "half-cock" notch safety but the design was revised in 1983 due to numerous inadvertent discharges.