Safety (firearms)
Encyclopedia
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...
s, a safety or safety catch is a mechanism used to help prevent the accidental discharge
Accidental discharge
Accidental discharge is the event of a firearm discharging at a time not intended by the user. Perhaps most commonly, accidental discharges occur when the trigger of the firearm is deliberately pulled for a purpose other than shooting—dry-fire practice, demonstration,...
of a firearm, helping to ensure safer handling.
Safeties can generally be divided into subtypes such as internal safeties (which typically do not receive input from the user) and external safeties (which typically allow the user to give input, for example, toggling a lever from "on" to "off" or something similar). Sometimes these are called "passive" and "active" safeties (or "automatic" and "manual"), respectively.
Firearms with the ability to allow the user to select various fire modes
Selective fire
A selective fire firearm has at least one semi–automatic and one automatic mode, which is activated by means of a selector which varies depending on the weapon's design. Some selective fire weapons utilize burst fire mechanisms to limit the maximum or total number of shots fired automatically in...
may have separate switches for safety and for mode selection (e.g. Thompson submachine gun
Thompson submachine gun
The Thompson is an American submachine gun, invented by John T. Thompson in 1919, that became infamous during the Prohibition era. It was a common sight in the media of the time, being used by both law enforcement officers and criminals...
) or may have the safety integrated with the mode selector as a fire selector with positions from safe to semi-automatic to full-automatic fire (e.g. M16
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
).
Some firearms manufactured after the late 1990s include 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 lock
Trigger lock
A trigger lock is a device designed to prevent a firearm from being discharged while the device is in place. Generally, two pieces come together from either side behind the trigger and are locked in place, which can be unlocked with a key or combination. This physically prevents the trigger from...
s, bore locks, and gun safes.
Manual safety
The most common form of safety mechanism is a switch that, when set to the "safe" position, prevents a pull of the trigger from firing the firearm. Designs of such 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. These 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.Grip safety
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. The Uzi submachine gun is another example of a firearm with a grip 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.
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.
Decocker
Most traditional double-action semi-automatic (DA/SA) pistols are designed to be carried with the hammer down (uncocked) on a chambered round, with or without a manual safety engaged. The pistol is considered safe in this state as the "double-action" pull that both cocks and fires the firearm is both longer and heavier than the "single-action" pull that simply releases the cocked hammer. However, the act of cycling the action (slide or bolt) on such a firearm (as a natural consequence of discharging the firearm, or to chamber the first round) will leave the hammer cocked in single-action mode. To return the pistol to its safe state, it is necessary to uncock (decock) the hammer, usually by holding the hammer spur, carefully pulling the trigger, and then slowly lowering the hammer on the firing pin. This process is dangerous if done carelessly or in adverse conditions, and violates the third rule of gun safetyGun safety
Gun safety is a collection of rules and recommendations that can be applied when handling firearms. The purpose of gun safety is to eliminate or minimize the risks of unintentional death, injury or damage caused by improper handling of firearms....
; "keep your finger off the trigger until you are on target and ready to fire".
A decocker or manual decocking lever allows the hammer to be dropped on a live cartridge without risk of discharging it, usually by blocking the hammer or retracting or covering the firing pin
Firing pin
A firing pin or striker is part of the firing mechanism used in a firearm or explosive device e.g. an M14 landmine or bomb fuze. Firing pins may take many forms, though the types used in landmines, bombs, grenade fuzes or other single-use devices generally have a sharpened point...
before releasing the sear
Sear (firearm)
In a firearm, the sear is the part of the trigger mechanism which holds the hammer or striker back until the correct amount of pressure has been applied to the trigger; at which point the hammer or striker is released to discharge the weapon...
. This eliminates the need to control the fall of the hammer although, since all mechanisms can fail, it is necessary to keep the muzzle of the gun pointed in a safe direction while decocking.
A decock/safety is a combination manual safety switch and decocking lever. Two popular variants exist. In the "three-way" system, made popular by Heckler & Koch
Heckler & Koch
Heckler & Koch GmbH is a German defense manufacturing company that produces various small arms. Some of their products include the SA80, MP5 submachine gun, G3 automatic rifle, the G36 assault rifle, the HK 416, the MP7 personal defense weapon, the USP series of handguns, and the high-precision...
pistols, the handler may decock the firearm by pushing down on the safety lever from the "Fire" setting, or engage the safety (even on a cocked firearm) by pushing the lever upwards. A simpler "two-way" system was popularized by the Walther PP: engaging the safety also uncocks the firearm.
The Sig Sauer line of pistols, such as the SIG P226
SIG P226
The SIG P226 is a full-sized, service-type pistol made by SIG Sauer. It is chambered for the 9×19mm Parabellum, .40 S&W, .357 SIG, and .22 Long Rifle. It is essentially the same basic design of the SIG P220, but developed to use higher capacity, staggered-column magazines in place of the...
, frequently feature decocking levers. The earliest use of a single-action decocker was the Vis Wz 35 redesign in 1932 to enable horsemen to safely holster their firearm with one hand. The earliest use of a cocking/decocking lever is the Sauer 38H
Sauer 38H
The Sauer 38H or often just H was a small semi-automatic pistol made in Nazi Germany from 1938 until just after the end of World War II by J. P. Sauer & Sohn, then based in Suhl, Germany. The "H" in the model number denotes "hammerless"—the pistol uses an internal hammer.-Development:Sauer...
from 1938. Ruger
Sturm, Ruger
Sturm, Ruger & Company, Incorporated is a Southport, Connecticut-based firearm manufacturing company, better known by the shortened name Ruger. Sturm, Ruger produces bolt-action, semi-automatic, full-automatic, and single-shot rifles, shotguns, semi-automatic pistols, and single- and double-action...
until 2007 manufactured "decock-only" variants of its P-series pistols, and the "two-way" decocking safety has been available on these pistols since their introduction.
Drop safeties
Many jurisdictions such as the State of CaliforniaCalifornia
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
require some form of "drop safety" on all new firearms, designed to reduce the chance of a firearm accidentally discharging when dropped or roughly handled. 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. Drop tests were introduced with the federal Gun Control Act of 1968
Gun Control Act of 1968
The Gun Control Act of 1968 , by president Lyndon Johnson, is a federal law in the United States that broadly regulates the firearms industry and firearms owners...
for imported guns.
Safety notch
A safety notch is one of the oldest forms of drop safety, used on older single-action revolvers manufactured before the invention of the hammer block, some lever action rifles, 1911-pattern guns, and hammer-fired semi-automatics that were designed before the invention of the firing pin block. The safety notch is a relief cut made in the tumbler that is connected mechanically to the hammer that allows the sear to catch and hold the hammer a short distance from the pin or cartridge primer, in a "half-cockHalf-cock
Half-cock is a technical firearms term referring to the position of the hammer where the hammer is partially but not completely cocked. Many firearms, particularly older firearms, had a notch cut into the hammer allowing half-cock, as this position would neither allow the gun to fire nor permit...
ed" position. The safety notch works first by allowing the handler to retract the hammer a short distance from the firing pin or primer, such that dropping the firearm on its hammer will not result in an energy transfer to the pin or spur, which could then discharge a chambered cartridge. A second purpose is to allow the sear to "catch" a hammer that is falling when the trigger has not been pulled, such as in cases where a drop jarred the sear loose or when the hammer was not fully cocked before being released. 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. A certain amount of manual dexterity and familiarity with a firearm is also required to "half-cock" a firearm; unfamiliarity with how to engage the "half-cock" position can result in accidental discharges.
Firing pin block
A firing pin block is a mechanical block used in semi-automatic firearms and some revolvers that, when at rest, obstructs forward travel of the firing pinFiring pin
A firing pin or striker is part of the firing mechanism used in a firearm or explosive device e.g. an M14 landmine or bomb fuze. Firing pins may take many forms, though the types used in landmines, bombs, grenade fuzes or other single-use devices generally have a sharpened point...
, but is linked to the trigger mechanism and clears the obstruction to the pin just before the hammer or striker is released. 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 pin is dropped or struck by another object.
Hammer block
A hammer block is similar to a firing pin block. 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. This allows the hammer to contact the primer or firing pin only when the trigger is pulled.Transfer bar
A transfer bar is also used in revolvers, but works the opposite way from a hammer block. The transfer bar has the spur that would otherwise be on the hammer, or encloses a firing pin similar to autoloading designs. The hammer itself cannot contact a loaded cartridge, but must instead strike the transfer bar, which then contacts the cartridge primer with the spur or pin. The transfer bar is normally positioned out of line with the hammer's travel, but is moved into place by the normal action of the trigger, providing similar "drop safety" to a firing pin block.Bolt interlocks and trigger disconnects
Popular on bolt, pump and lever-action firearms such as shotguns and rifles, a bolt interlock disengages or blocks the trigger if, for any reason, the bolt/breech is not in its fully closed, ready position. A variation is the trigger disconnect which prevents the gun from firing until the gun has not only been fully and completely cycled, but the trigger is released and squeezed again. This defines the behavior of semi-automatic firearmSemi-automatic firearm
A semi-automatic, or self-loading firearm is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine...
s which require a separate trigger pull to fire each successive cartridge and ready the next, and this is the preferred mechanism of disengaging the trigger on repeating-action firearms. 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. As such these features are often not considered "true" safeties, although the interlock helps prevent misfires due to a bullet not being fully in the breech when its primer is struck by the pin (known as firing "out of battery"), and passing handguns or rifles to another person with the action open (known as "show clear") is recommended by elementary gun safety
Gun safety
Gun safety is a collection of rules and recommendations that can be applied when handling firearms. The purpose of gun safety is to eliminate or minimize the risks of unintentional death, injury or damage caused by improper handling of firearms....
.
Magazine disconnects
A magazine disconnect is an internal mechanism that engages a mechanical safety such as a block or trigger disconnect when the firearm's magazine is removed. This feature was first used with the Browning Hi-PowerBrowning Hi-Power
The Browning Hi-Power is a single-action, 9 mm semi-automatic handgun. It is based on a design by American firearms inventor John Browning, and completed by Dieudonné Saive at Fabrique Nationale of Herstal, Belgium. Browning died in 1926, several years before the design was finalized...
pistol. As with any firearm feature, there is debate regarding the necessity of a magazine disconnect. Historically, most magazine-capable firearm designs have had no magazine disconnect. There are exceptions, notably Ruger
Sturm, Ruger
Sturm, Ruger & Company, Incorporated is a Southport, Connecticut-based firearm manufacturing company, better known by the shortened name Ruger. Sturm, Ruger produces bolt-action, semi-automatic, full-automatic, and single-shot rifles, shotguns, semi-automatic pistols, and single- and double-action...
rimfire rifles and some of their newer handgun designs, and the U.S. State of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
passed legislation in 2006 requiring magazine disconnects on all new handgun designs sold in the state starting January 1, 2007, which has resulted in their widespread availability in other jurisdictions as well.
The arguments in favor of a magazine disconnect are that if the gun cannot fire without a magazine, then an accidental discharge can be prevented if someone removes the magazine but forgets that a round has been chambered. Also, if losing possession of the firearm is imminent, the operator can render the firearm useless by removing the magazine.
The arguments against a magazine disconnect are that without a magazine the firearm is useless except as a club. Without the feature, if a magazine was lost or otherwise not available, then at least the gun could be chambered with a single round to be used as a single shot firearm. From a technical standpoint, a magazine disconnect adds extra parts to a firearm and thus increases complexity which creates additional risk of component failure while potentially increasing production costs. In some cases, the disconnect adversely affects trigger feel, and hence affects accuracy.
Some experienced firearms operators see little value in having a magazine disconnect due to their belief that proper firearm handling and care offer equal safety. Some also see magazine disconnects being introduced as a way to appease anti-gun politicians, while lessening firearm accuracy, reliability, and safety (for always keeping a defensive weapon ready to fire, even during a tactical reload during a firefight).
Integrated trigger safeties
These safeties, similar to grip safeties, are de-activated as a natural consequence of the shooter firing the firearm, but are engaged in most other circumstances. The trigger is composed of two interdependent parts, and the shooter in firing the firearm manipulates both parts of the trigger. Conversely, unintentional pressure or a strike against the trigger is unlikely to do so, and such an action will not fire the firearm. Such a design, made popular by Glock pistolGlock pistol
The Glock pistol, sometimes referred to by the manufacturer as Glock "Safe Action" Pistol, is a series of semi-automatic pistols designed and produced by Glock Ges.m.b.H., located in Deutsch-Wagram, Austria. The company's founder, engineer Gaston Glock, had no experience with firearm design or...
s, incorporates a trigger with a spring-loaded lever in its lower half. This lever which protrudes from the trigger face must be fully depressed in order to disengage a lock that allows the main trigger body to move. Unintentional pressure against the top of the trigger without pressing the lever does not disengage the lock and the trigger will not move. Other designs include a spring-loaded pad that forms the upper portion of the trigger face and manipulates a similar lock. This design has more moving parts, but is advantageous in that accidental pressure on the lock release has reduced leverage thus requiring more force to pull the main trigger, where force against the lower portion does not release the lock and will not move the trigger.
Other safeties
Examples of the variety of typical semi-auto mechanisms are a stiff double-action trigger pull with the safety off (Beretta 92F/FSBeretta 92
The Beretta 92 is a series of semi-automatic pistols designed and manufactured by Beretta of Italy. The model 92 was designed in 1972 and production of many variants in different calibers continues today...
), a double-action with no external safety (SIG Sauer P-series, or Kel-Tec P-32
Kel-Tec P-32
The Kel-Tec P-32 is a compact semi-automatic pistol using the short-recoil principle of operation. Chambered in .32 ACP, it is popular for concealed carry in the United States. It was designed by George Kellgren, the Swedish firearms designer associated earlier with the Husqvarna, Intratec, and...
), or a crisp single action trigger pull with a manual safety engaged (M1911, FN Five-seven and certain configurations of the HK USP
Heckler & Koch USP
The USP is a semi-automatic pistol developed in Germany by Heckler & Koch GmbH of Oberndorf am Neckar as a replacement for the P7 series of handguns.-History:...
). An alternative are striker-fired or "safe action
Safe action
The "safe action" is a firing pin lock system which Glock developed to be used in the vast majority of their pistols. The action is very similar to the quick action used by Walther and other pistol manufacturers....
" type firearms which have a consistent trigger pull requiring force greater than required by a single-action design, but lighter than needed for a double-action trigger. Many such firearms do not have an external safety or external hammer (Glock pistol
Glock pistol
The Glock pistol, sometimes referred to by the manufacturer as Glock "Safe Action" Pistol, is a series of semi-automatic pistols designed and produced by Glock Ges.m.b.H., located in Deutsch-Wagram, Austria. The company's founder, engineer Gaston Glock, had no experience with firearm design or...
s and the Walther P99
Walther P99
The Walther P99 is a semi-automatic pistol developed by the German company Carl Walther GmbH Sportwaffen of Ulm for law enforcement, security forces and the civilian shooting market as a replacement for the Walther P5 and the P88...
and variants). In both cases, the action is very simple—a trigger pull always sends a discharge—and there are internal safeties to prevent non-trigger-pull discharge (e.g., dropping the gun).
Pistols
Almost all modern semi-automatic handguns, except some exact replicas of antique models, have some form of safety mechanism including a "drop safety" that requires a trigger pull to discharge a cartridge. Single-action designs such as the Colt 1911 virtually always incorporate a manual safety, while traditional double-action pistols incorporate a decocker, manual safety, or both. However, the exact configuration depends on handgun type, year, make, and model. Double-action only (DAO) pistols, which usually use designs similar to traditional double-action but without the ability to remain cocked, do not usually have external safeties.Single-action revolvers
Single-action revolversRevolver
A revolver is a repeating firearm that has a cylinder containing multiple chambers and at least one barrel for firing. The first revolver ever made was built by Elisha Collier in 1818. The percussion cap revolver was invented by Samuel Colt in 1836. This weapon became known as the Colt Paterson...
have no external safeties, and they usually have no internal safeties, such as a hammer block or transfer bar, to render them drop-safe. Most single action revolvers have a half-cock "safety" notch on the hammer, but many of these are not drop-proof. Real antiques are in this category; modern non-exact replicas may have internal hammer blocks. Carrying such firearms with a loaded chamber under the hammer, rather than with the hammer left down on an empty chamber, is not safe.
However, some single-action revolvers have relief cuts in between cylinder bores that allow the hammer to be rested directly upon the cylinder with no chance of interacting with loaded cartridges or primers. These are also known colloquially as "safety notches." They are usually found on black-powder revolvers, but there are also cartridge-firing revolvers with safety notches.
Double-action revolvers
Most double-action revolversRevolver
A revolver is a repeating firearm that has a cylinder containing multiple chambers and at least one barrel for firing. The first revolver ever made was built by Elisha Collier in 1818. The percussion cap revolver was invented by Samuel Colt in 1836. This weapon became known as the Colt Paterson...
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 double-action revolvers with external safeties are unusual cases available only on special order or modified through aftermarket conversions.
Glock Semi-automatic pistols
Pistols made and imported by GlockGlock
Glock Ges.m.b.H. is a weapons manufacturer headquartered in Deutsch-Wagram, Austria, named after its founder, Gaston Glock...
incorporate a design with three levels of integrated safety, known as safe action
Safe action
The "safe action" is a firing pin lock system which Glock developed to be used in the vast majority of their pistols. The action is very similar to the quick action used by Walther and other pistol manufacturers....
; there are no external safety switches on these handguns. First, an integrated trigger latch prevents the trigger body from moving unless the trigger is positively squeezed. Second, the gun's striker-firing mechanism is locked in place by an extension bar linked to the trigger; the striker cannot move unless the trigger is depressed. Third, a firing pin block actuated by the same extension bar prevents the pin coming into contact with the primer unless the trigger is pulled to clear the block. Although not generally considered a safety feature, the resting state of the gun (excluding a dry/misfire) has the striker in a "half-cocked" state; pulling the trigger will fully cock the weapon before releasing the striker, and the mechanism is designed to have insufficient force to ignite the primer of an active cartridge from this state even if the sear lock and firing pin block both fail.
Rifles
Rifles come with various safeties. Some use a cross-bolt safety button, others a wing safety at the rear, or even a "half-cock" notch (such as found on older lever action rifles.) The M1 GarandM1 Garand
The M1 Garand , was the first semi-automatic rifle to be generally issued to the infantry of any nation. Called "the greatest battle implement ever devised" by General George S...
created a safety with a metal rocking lever at the front of the trigger guard that is now called the Garand-style safety, used in the Ruger Mini-14 rifle and Marlin Camp Carbine
Marlin Camp Carbine
The Marlin Camp Carbine is a self-loading carbine chambered for either 9mm Parabellum or .45 ACP, formerly manufactured by Marlin Firearms Company of North Haven, Connecticut. The carbine has been discontinued since 1999....
.
Some bolt action rifle safeties have three positions: "fire" which allows the gun to fire, "safe" which does not allow the gun to fire or the action to open, and an intermediate third position which cannot fire but allows the action to be opened to unload the rifle.