The slide on the majority of fully/

semi-automatic pistol A semi-automatic pistol (also called a self-loading pistol, autopistol, or autoloading pistol) is a repeating firearm, repeating handgun that automatically ejects and loads cartridge (firearms), cartridges in its chamber (firearms), chamber afte ...

s is the upper part that reciprocates ("slides") with

recoil Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, for according to Newton's third law the force requ ...

during the gun's operating cycle. It serves as the bolt carrier group (BCG) and partly as the receiver, and generally houses the

firing pin A firing pin or striker is a part of the firing mechanism of a firearm that impacts the primer in the base of a cartridge and causes it to fire. In firearms terminology, a striker is a particular type of firing pin where a compressed sprin ...

/ striker, the extractor and frequently also the

barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden stave (wood), staves and bound by wooden or metal hoops. The word vat is often used for large containers ...

, and provides a mounting platform for

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

and optical sights. Through the principles of

short recoil Recoil operation is an operating mechanism used to implement locked-breech autoloading firearms. Recoil operated firearms use the energy of recoil to cycle the action, as opposed to gas operation or blowback operation using the pressure of the ...

or simple blowback operations, the slide is moved backwards with each shot by the energy of expanding gasses caused by the combusting

propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicle ...

(often a

nitrocellulose Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...

-based

smokeless powder Finnish smokeless powder Smokeless powder is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to black powder. Because of their similar use, both the original black powder formula ...

, very rarely

black powder Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate, potassium ni ...

). Because the slide is spring-loaded, once at the rearmost position, the spring tension will push it back towards the front. Generally, this slide movement cycle serves three functions: the extractor will empty the chamber by pulling out the spent casing from the previous shot (which then gets removed out of the gun by the ejector), the slide

inertia Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes the velocity to change. It is one of the fundamental principles in classical physics, and described by Isaac Newto ...

will cock the

hammer A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nail (fastener), nails into wood, to sh ...

/ striker to prepare for the next shot, and the bolt will push a new cartridge from the

magazine A magazine is a periodical literature, periodical publication, print or digital, produced on a regular schedule, that contains any of a variety of subject-oriented textual and visual content (media), content forms. Magazines are generally fin ...

into the chamber when the slide comes back forward. This

action Action may refer to: * Action (philosophy), something which is done by a person * Action principles the heart of fundamental physics * Action (narrative), a literary mode * Action fiction, a type of genre fiction * Action game, a genre of video gam ...

cycle will be repeated for continued firing as long as the magazine contains rounds and there is no failure to extract/ eject (which causes

stovepiping In intelligence gathering, stovepiping is the presentation of information without proper context. It can be caused by the specialized nature or security requirements of a particular intelligence-collection technology. Alternatively, the lack of c ...

and double-feeding), failure to feed, or out-of-battery malfunction. Fully/semi-automatic air pistols' slides operate with similar principles as

firearm A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originate ...

s, except they utilize

pneumatic Pneumatics (from Greek 'wind, breath') is the use of gas or pressurized air in mechanical systems. Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A centrally located a ...

energy from

compressed gas Bottled gas is a term used for substances which are gaseous at standard temperature and pressure (STP) and have been compressed and stored in carbon steel, stainless steel, aluminum, or composite containers known as gas cylinders. Gas sta ...

(usually

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

, ,

propane Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum ref ...

refrigerant A refrigerant is a working fluid used in the cooling, heating, or reverse cooling/heating cycles of air conditioning systems and heat pumps, where they undergo a repeated phase transition from a liquid to a gas and back again. Refrigerants are ...

s) instead of burning propellants. Because air pistols typically have much lower

muzzle energy Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle (firearm), muzzle of a firearm. Without consideration of factors such as aerodynamics and gravity for the sake of comparison, muzzle energy is used as a rough indi ...

than firearms, there is less recoil that can be used to operate the slide. However, because airgun pellets/ shots have no casings that needed to be extracted (unlike firearm cartridges), a very brief slide movement is sufficient to cycle the action and load the subsequent shot, so only a small amount of energy is needed to move the slide. On most modern designs, once the

is empty, a

slide stop A slide stop, sometimes referred to as a slide lock, slide release, slide catch, or bolt hold open, is a function on a semi-automatic handgun that both visually indicates when it has expended all loaded ammunition Ammunition, also known a ...

will catch and lock the slide at its rearmost position, and will only be released to move back forward after the slide release is depressed. Having the slide automatically loading the chamber and cocking the hammer/striker with each prior shot is essential for the function of double-action/

single-action A trigger is a mechanism that actuates the function of a ranged weapon such as a firearm, airgun, crossbow, or speargun. The word may also be used to describe a switch that initiates the operation of other non-shooting devices such as a t ...

pistols.

Hammerless A hammerless firearm is a firearm that lacks an exposed hammer (firearm), hammer or hammer spur. Although it may not literally lack a hammer, it lacks an external hammer that the user can manipulate directly. One of the disadvantages of an expo ...

and striker-fired pistols, lacking an external hammer that can be directly manipulated, need to have the whole slide manually pulled back to cock the hammer/striker if the gun is not already cocked for firing.

References

{{Firearms Firearm components

See also

References