Safety (firearms)

In firearms, a safety or safety catch is a mechanism used to help prevent the accidental discharge of a firearm, helping to ensure safer handling.

Safeties can generally be categorized as either internal safeties (which typically do not receive input from the user) and external safeties (which the user may manipulate manually, for example, switching a lever from "safe" to "fire"). Sometimes these are called "passive" and "active" safeties (or "automatic" and "manual"), respectively. External safeties typically work by preventing the trigger from being pulled or preventing the firing pin from striking the cartridge.

Firearms which allow the user to select various fire modes may have separate controls for safety and for mode selection (e.g. Thompson submachine gun) or may have the safety integrated with the mode selector as a fire selector with positions for safe, semi-automatic, and fully automatic fire (e.g. M16 rifle).

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. These integral locking mechanisms are intended as child-safety devices during unattended storage of the firearm—not as safety mechanisms while carrying. Other devices in this category are trigger locks, bore locks, and gun safes.

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. Manual safeties are as varied as the designs of firearms themselves, but the two most common mechanisms are a block or latch that prevents the trigger and/or firing mechanism from moving, and a device that disconnects the trigger from the firing mechanism of the firearm. Other designs may block the hammer or striker from forward movement or act as a block to prevent them from contacting the firing pin. In addition some manual safeties such as the Ruger SR9 pictured lock the pistol's slide closed when in Safe position whereas, for example, S&W M&P manual safeties do not lock the slide closed. 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. The safety must be OFF to clear the weapon. In the M&P design, the slide can be manually actuated and a chambered round ejected with the manual safety in safe position. One possible benefit of the slide-safety lock may be that, upon holstering, the slide cannot be snagged and hung up out of battery. Manual Safeties are the oldest forms of "active" safety mechanism and are widely used; however, many "double-action" firearms such as revolvers do not have manual safeties as the longer, harder trigger pull to cock and fire double-action provides adequate trigger safety, while keeping the firearm in a more ready state.

A grip safety is a lever or other device situated on the grip of a firearm which must be actuated by the operator's hand, as a natural consequence of holding the firearm in a firing position, in order for the firearm to fire. It is usually similar to a manual safety in its function, but is momentary; the safety is deactivated only while the shooter maintains their hold on the grip, and is reactivated immediately once the shooter releases it. The M1911 design is a popular example of a handgun with a grip safety, while the Uzi submachine gun and the HS2000 (marketed in the US as the Springfield Armory XD) and its descendants are other notable examples of this type of safety.

A related grip-type safety is the decocking grip found on some H&K pistols like the P7 Series. The firearm is cocked and ready to fire only when the front of the grip is squeezed by the operator. When the grip is released, the firearm is decocked, and the single-action trigger will not cock the firearm, therefore it will not fire unless the grip is squeezed and the trigger pulled. Alternatively, the trigger can first be pulled and then it will fire when the grip is subsequently squeezed. Finally, if both the grip is squeezed and the trigger pulled simultaneously, the pistol will fire.

Another, unusual variant was found in the Ortgies semi-automatic pistols. To disengage the safety, a user would squeeze a lever until flush with the rear of the grip. The lever then would latch in the disengaged position until the user released it again by pressing a button under the slide, whereupon tension from the striker spring would push it back to the engaged position. Thus engaging the safety also relieved some tension in the striker spring. 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. Gripping the pistol tightly is all it takes to disengage the safety.