A firing pin or striker is part of the firing mechanism used in a firearm or explosive device, designed to ignite combustions/detonations by delivering an impact force to shock-sensitive compounds known as primers. Firing pins may take many forms, though the types used in fuzes for single-use devices (such as landmines, artillery shells, cluster munitions and grenades) generally have a sharpened point. In contrast, firing pins used in firearms usually have a small, rounded portion designed to strike the primer of a cartridge, detonating the priming compound, which then ignites the propellant (inside) or fires the detonator and booster.
Typically, firing pins or strikers are made from steel, aluminum or titanium. However, for specialist applications such as zero metal mines, non-metallic materials are used such as glass ceramic.
A firing pin per se is a lightweight rod which only serves to transfer the momentum received from a spring-loaded hammer, in the same fashion a punch/chisel will relay the blow from a mallet. A striker is a hybrid piece directly connected to a spring, and is usually heavier and bulkier, without needing a separate hammer. Striker mechanisms are generally simpler, since they combine both functions of hammer and firing pin in one piece.
The firing pin or striker is generally located in the bolt of a repeating firearm. Firearms that do not have bolts, such as revolvers and many types of single-shot firearms, generally have a very short firing pin in the action frame, or else attached to the hammer itself. These types of firearms are almost never striker-fired, as there is insufficient space to house a striker mechanism. Strikers are most commonly found in semi-automatic pistols and bolt-action firearms.
The typical firing pin is a small simple rod with a hardened, blunted/rounded tip that strikes and crushes the primer. The rounded end ensures the primer is indented rather than pierced, as would otherwise happen if the firing pin were sharply pointed. Most firing pins are connected to a return spring to pushes them back and out of contact with the primer, and often will have an integrated passive safety mechanism such as a catch that blocks them from moving forward unless the trigger is depressed, or a transfer bar (also trigger-actuated) that must be in place to allow the hammer to impact the firing pin. This integrated safety is in addition to any manually operated safety mechanisms that deactivate the trigger or hammer.
Handguns with reciprocating actions such as semi-automatic pistols, will often use a firing pin that is too short to project when depressed flush by the hammer. This type of firing pin, called an inertial firing pin, must be struck by a full fall of the hammer to provide enough forward momentum to reach and strike the primer. If the hammer is down, resting on the firing pin, it is very unlikely that an external blow to the rear will provide enough kinetic energy to the firing pin to detonate the primer. Most variants of the M1911 pistol use this type of firing pin.
Many firing pins are stamped from sheet steel, forming a rectangular cross-section rather than a round one. These will often have a cylindrical section at the front rather than a hemispherical one and are fairly common in rimfire firearms. Sturm, Ruger & Co., for example, uses sheet metal firing pins in its 10/22 carbine and Mark II pistol.
High performance firing pins are often made from materials lighter than steel, such as titanium. The lighter mass increases the travel speed nd reduces the lock time, i.e. the time from trigger pull to the bullet leaving the barrel. There is some controversy as to whether or not such firing pins are really necessary, with some claiming them to impact more weakly than the regular steel ones.
Strikers are basically spring-loaded firing pins, generally of a one- or two-piece construction. In the one-piece striker, the striker is turned on a lathe out of a round bar of metal, much larger in diameter than a firing pin, to provide the mass required to detonate the primer. Two-piece strikers generally consist of a firing pin attached to a heavier rear section—in essence a hammer attached to the base of a firing pin. Two-piece strikers are commonly found in bolt-action rifles, while single-piece strikers are found in pistols, such as the Glock.Some self-loading rifles, like the vz. 58, AN-94, and VSS Vintorez (as well as its derivative AS Val) use one or two-piece striker mechanisms rather than a rotating hammer.
Mechanisms involving firing pins can be used also in other pyrotechnical systems, ranging from hand grenades to chemical oxygen generators.
The percussion cap or percussion primer, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzleloader firearm locks enabling them to fire reliably in any weather condition. This crucial invention gave rise to the caplock mechanism or percussion lock system using percussion caps struck by the hammer to set off the gunpowder charge in percussion guns including percussion rifles and cap and ball firearms. Any firearm using a caplock mechanism is a percussion gun. Any long gun with a caplock mechanism and rifled barrel is a percussion rifle. Cap and ball describes caplock firearms discharging a single bore-diameter spherical bullet with each shot.
A booby trap is a device or setup that is intended to kill, harm, or surprise a human being or an animal. It is triggered by the presence or actions of the victim and sometimes has some form of bait designed to lure the victim towards it. The trap may be set to act upon trespassers that enter restricted areas, and it can be triggered when the victim performs an action. It can also be triggered by vehicles driving along a road, as in the case of improvised explosive devices (IEDs).
An explosive booster is a sensitive explosive charge that acts as a bridge between a conventional detonator and a low-sensitivity explosive such as TNT. By itself, the initiating detonator would not deliver sufficient energy to set off the low-sensitivity charge. However, it detonates the primary charge, which then delivers an explosive shockwave that is sufficient to detonate the secondary, main, high-energy charge.
A semi-automatic pistol is a type of repeating single-chamber handgun (pistol) that automatically cycles its action to insert the subsequent cartridge into the chamber (self-loading), but requires manual actuation of the trigger to actually discharge the following shot. As a result, only one round of ammunition is fired each time the trigger is pulled, as the pistol's fire control group disconnects the trigger mechanism from the firing pin/striker until the trigger has been released and reset.
A breechblock is the part of the firearm action that closes the breech of a weapon at the moment of firing.
The Gammon bomb, officially known as the No. 82 grenade was a British hand grenade used during World War II.
The British No. 69 was a hand grenade developed and used during the Second World War. It was adopted into service due to the need for a grenade with smaller destructive radius than the No. 36M "Mills bomb". This allowed the thrower to use a grenade even when there was little in the way of defensive cover. In contrast, the much greater destructive radius of the Mills bomb than its throwing range forced users to choose their throwing point carefully, in order to ensure that they would not be wounded by the shrapnel explosion of their own grenade.
A trigger is a mechanism that actuates the firing sequence of a firearm, airgun, crossbow, or speargun. A trigger may also start other non-shooting mechanisms such as a trap, a switch or a quick release. A small amount of energy applied to the trigger causes the release of much more energy.
Anti-personnel mines are a form of mine designed for use against humans, as opposed to anti-tank mines, which are designed for use against vehicles. Anti-personnel mines may be classified into blast mines or fragmentation mines, the latter may or may not be a bounding mine.
The PMN series of blast anti-personnel mines were designed and manufactured in the Soviet Union. They are one of the most widely used and commonly found devices during demining operations. They are sometimes nicknamed "black widow" because of their dark casings.
An anti-handling device is an attachment to or an integral part of a landmine or other munition such as some fuze types found in general-purpose air-dropped bombs, cluster bombs and sea mines. It is designed to prevent tampering or disabling, or to target bomb disposal personnel. When the protected device is disturbed, it detonates, killing or injuring anyone within the blast area. There is a strong functional overlap of booby traps and anti-handling devices.
The Model L is a Spanish 5.56×45mm NATO assault rifle developed in the late 1970s at the state-owned small arms research and development establishment CETME located in Madrid. The rifle retains many of the proven design elements the institute had used previously in its CETME Model 58 battle rifles.
The following are terms related to firearms and ammunition topics.
The Type 4 70 mm AT Rocket Launcher was a Japanese rocket launcher used during the last year of World War II. It was to be used in the Japanese mainland in case of an invasion by the Allies.
In military munitions, a fuze is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze designs can be seen in cutaway diagrams.
A grenade is an explosive weapon typically thrown by hand, but can also refer to an shell shot out by a rifles or a grenade launcher. A modern hand grenade generally consists of an explosive charge ("filler"), a detonator mechanism, an internal striker to trigger the detonator, and a safety lever secured by a linchpin. The user pulls the safety pin before throwing, and once thrown the safety lever gets released, allowing the striker to trigger a primer that ignites a fuze, which burns down to the detonator and explodes the main charge.
An artillery fuze or fuse is the type of munition fuze used with artillery munitions, typically projectiles fired by guns, howitzers and mortars. A fuze is a device that initiates an explosive function in a munition, most commonly causing it to detonate or release its contents, when its activation conditions are met. This action typically occurs a preset time after firing, or on physical contact with or detected proximity to the ground, a structure or other target. Fuze, a variant of fuse, is the official NATO spelling.
A contact fuze, impact fuze, percussion fuze or direct-action (D.A.) fuze (UK) is the fuze that is placed in the nose of a bomb or shell so that it will detonate on contact with a hard surface.
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.
The Type 99 81 mm mortar was a Japanese mortar used primary by Imperial Japanese Army during World War II. The Type 99 designation was given to this gun as it was accepted in the year 2599 of the Japanese calendar (1939). The Type 99 81 mm mortar is typical of the Stokes-Brandt type mortar. The Type 99 81 mm mortar differs from the Type 97 81 mm infantry mortar in the shortness of its tube and in the method of firing. The differences between the Type 99 and the US 81-mm mortar, M1 are pronounced.