![Under Lever Spring Piston Air Rifles](https://upload.wikimedia.org/wikipedia/commons/2/22/Under_Lever_Spring_Piston_Air_Rifles.jpg)
An air gun or airgun is a
gun
A gun is a ranged weapon designed to use a shooting tube (gun barrel) to launch projectiles. The projectiles are typically solid, but can also be pressurized liquid (e.g. in water guns/cannons, spray guns for painting or pressure washing, p ...
that fires
projectile
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in ...
s
pneumatic
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A central ...
ally with
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
or other
gas
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...
es that are mechanically pressurized ''without'' involving any
chemical reaction
A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...
s, in contrast to a
firearm
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions).
The first firearms originated in 10th-century China, when bamboo tubes ...
, which pressurizes gases ''chemically'' via
oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
of
combustible
A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...
propellant
A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...
s that generates propulsive energy by breaking
molecular bond
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...
s.
Air guns come in both
long gun
A long gun is a category of firearms with long barrels. In small arms, a ''long gun'' or longarm is generally designed to be held by both hands and braced against the shoulder, in contrast to a handgun, which can be fired being held with a single ...
(air rifle) and
handgun
A handgun is a short- barrelled gun, typically a firearm, that is designed to be usable with only one hand. It is distinguished from a long gun (i.e. rifle, shotgun or machine gun, etc.), which needs to be held by both hands and also braced ...
(air pistol) forms. Both types typically propel metallic projectiles that are either
diabolo
The diabolo ( ; commonly misspelled ''diablo'') is a juggling or circus prop consisting of an axle () and two cups (hourglass/egg timer shaped) or discs derived from the Chinese yo-yo. This object is spun using a string attached to two hand ...
-shaped
pellets or spherical
shot
Shot may refer to:
Arts, entertainment, and media
* ''Shot'' (album), by The Jesus Lizard
*''Shot, Illusion, New God'', an EP by Gruntruck
*'' Shot Rev 2.0'', a video album by The Sisters of Mercy
* "Shot" (song), by The Rasmus
* ''Shot'' (2017 f ...
s called
BBs, although in recent years
Minié ball
The Minié ball or Minie ball, is a type of hollow-based bullet designed by Claude-Étienne Minié, inventor of the French Minié rifle, for muzzle-loading rifled muskets. It was invented in 1847 and came to prominence in the Crimean War and ...
-shaped
cylindro-conoidal projectiles called
slug
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...
s are gaining more popularity. Certain types of air guns (usually air rifles) may also launch
fin
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...
-stabilized projectile such as
dart
Dart or DART may refer to:
* Dart, the equipment in the game of darts
Arts, entertainment and media
* Dart (comics), an Image Comics superhero
* Dart, a character from ''G.I. Joe''
* Dart, a ''Thomas & Friends'' railway engine character
* Dar ...
s (e.g.,
tranquilizer gun
A dart gun is an air rifle that fires a dart. The dart is tipped with a hypodermic needle and filled with a tranquilizer, vaccine, or antibiotic. A dart gun containing a tranquillizer is called a tranquillizer gun ( also spelled tranquilizer, tr ...
s) or hollow-shaft
arrow
An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers c ...
s (so-called "airbows").
The first air guns were developed as early as the 16th century, and have since been used in
hunting
Hunting is the human activity, human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products (fur/hide (skin), hide, ...
,
shooting sport
Shooting sports is a group of competitive and recreational sporting activities involving proficiency tests of accuracy, precision and speed in shooting — the art of using ranged weapons, mainly small arms (firearms and airguns, in forms such ...
and even in
warfare
War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regular ...
. There are three different power sources for modern air guns, depending on the design:
spring
Spring(s) may refer to:
Common uses
* Spring (season)
Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of ...
-
piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...
, pneumatic, or
bottled compressed gas (most commonly
carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
).
History
Air guns represent the oldest
pneumatic
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A central ...
technology. The oldest existing mechanical air gun, a bellows air gun dating back to about 1580, is in the
Livrustkammaren
The Royal Armoury ( sv, Livrustkammaren) is a museum in the Royal Palace in Stockholm, Sweden. It contains many artifacts of Swedish military history and Swedish royalty. It is the oldest museum in Sweden, established in 1628 by King Gustavus A ...
Museum in
Stockholm
Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, largest city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in Scandinavia. Approximately 980,000 people liv ...
. This is the time most historians recognize as the beginning of the modern air gun.
Throughout 17th to 19th century, air guns in .30 to .51
caliber
In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel Gauge (firearms) , bore – regardless of how or where the bore is measured and whether the f ...
s were used to
hunt big-game,
deer
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...
and wild
boar
The wild boar (''Sus scrofa''), also known as the wild swine, common wild pig, Eurasian wild pig, or simply wild pig, is a suid native to much of Eurasia and North Africa, and has been introduced to the Americas and Oceania. The species is no ...
. These air rifles were charged using a pump to fill an air reservoir and gave velocities from . They were also used in warfare, the most recognized example being the
Girandoni air rifle
The Girardoni air rifle was an air gun designed by Italian inventor Bartolomeo Girardoni circa 1779. The weapon was also known as the ''Windbüchse'' ("wind rifle" in German). One of the rifle's more famous associations is its use on the Lewi ...
.
At that time, they had compelling advantages over the primitive firearms of the day. For example, air guns could be discharged in wet weather and rain (unlike both
matchlock
A matchlock or firelock is a historical type of firearm wherein the gunpowder is ignited by a burning piece of rope that is touched to the gunpowder by a mechanism that the musketeer activates by pulling a lever or trigger with his finger. Before ...
and
flintlock
Flintlock is a general term for any firearm that uses a flint-striking lock (firearm), ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism its ...
musket
A musket is a muzzle-loaded long gun that appeared as a smoothbore weapon in the early 16th century, at first as a heavier variant of the arquebus, capable of penetrating plate armour. By the mid-16th century, this type of musket gradually d ...
s), and discharged much faster than
muzzle-loading guns.
Moreover, they were quieter than a firearm of similar caliber, had no muzzle flash, and were smokeless. Thus, they did not disclose the shooter's position or obscure the shooter's view, unlike the black powder muskets of the 18th and 19th centuries.
In the hands of skilled soldiers, they gave the military a distinct advantage. France, Austria and other nations had special
sniper
A sniper is a military/paramilitary marksman who engages targets from positions of concealment or at distances exceeding the target's detection capabilities. Snipers generally have specialized training and are equipped with high-precision r ...
detachments using air rifles. The Austrian 1770 model was named ''Windbüchse'' (literally "wind rifle" in German). The gun was developed in 1768 or 1769 by the
Tyrolean watchmaker, mechanic and gunsmith Bartholomäus Girandoni (1744–1799) and is sometimes referred to as the
Girandoni air rifle
The Girardoni air rifle was an air gun designed by Italian inventor Bartolomeo Girardoni circa 1779. The weapon was also known as the ''Windbüchse'' ("wind rifle" in German). One of the rifle's more famous associations is its use on the Lewi ...
or Girandoni air gun in literature (the name is also spelled "Girandony," "Giradoni" or "Girardoni".) The ''Windbüchse'' was about long and weighed , about the same size and mass as a conventional
musket
A musket is a muzzle-loaded long gun that appeared as a smoothbore weapon in the early 16th century, at first as a heavier variant of the arquebus, capable of penetrating plate armour. By the mid-16th century, this type of musket gradually d ...
. The air reservoir was a removable, club-shaped,
butt. The ''Windbüchse'' carried twenty-two .51
caliber
In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel Gauge (firearms) , bore – regardless of how or where the bore is measured and whether the f ...
(13 mm) lead balls in a tubular
magazine
A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...
. A skilled shooter could fire off one magazine in about thirty seconds. A shot from this air gun could penetrate a wooden board at a hundred paces, an effect roughly equal to that of a modern
9×19mm or
.45 ACP
The .45 ACP ( Automatic Colt Pistol) or .45 Auto (11.43×23mm) is a rimless straight-walled handgun cartridge designed by John Moses Browning in 1904, for use in his prototype Colt semi-automatic pistol. After successful military trials, it ...
caliber pistol.
Circa 1820, the Japanese inventor
Kunitomo Ikkansai developed various manufacturing methods for guns, and also created an air gun based on the study of Western knowledge ("
rangaku
''Rangaku'' (Kyūjitai: /Shinjitai: , literally "Dutch learning", and by extension "Western learning") is a body of knowledge developed by Japan through its contacts with the Dutch enclave of Dejima, which allowed Japan to keep abreast of Wester ...
") acquired from the
Dutch
Dutch commonly refers to:
* Something of, from, or related to the Netherlands
* Dutch people ()
* Dutch language ()
Dutch may also refer to:
Places
* Dutch, West Virginia, a community in the United States
* Pennsylvania Dutch Country
People E ...
in
Dejima
, in the 17th century also called Tsukishima ( 築島, "built island"), was an artificial island off Nagasaki, Japan that served as a trading post for the Portuguese (1570–1639) and subsequently the Dutch (1641–1854). For 220 years, it ...
.
The
Lewis and Clark Expedition
The Lewis and Clark Expedition, also known as the Corps of Discovery Expedition, was the United States expedition to cross the newly acquired western portion of the country after the Louisiana Purchase. The Corps of Discovery was a select gro ...
(1804) carried a reservoir air gun. It held 22 .46 caliber round balls in a tubular magazine mounted on the side of 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 staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...
. The butt served as the air reservoir and had a working pressure of . The rifle was said to be capable of 22 aimed shots per minute and had a rifled bore of and a groove diameter .
One of the first commercially successful and mass-produced air guns was manufactured by the William F. Markham's Markham Air Rifle Company in
Plymouth, Michigan
Plymouth is a city in Wayne County, Michigan, United States. The population was 9,370 at the 2020 census. The city of Plymouth is surrounded by Plymouth Township, but the two are administered autonomously. Plymouth is a western suburb of Metro ...
, US. Their first model air gun was the wooden ''Challenger'', marketed in 1886. In response, Clarence Hamilton from the neighboring Plymouth Air Rifle Company (later renamed to
Daisy Manufacturing Company in 1895) marketed their all-metal Daisy BB Gun in early 1888, which prompted Markham to respond with their ''Chicago'' model in 1888 followed by the ''King'' model in 1890. The ''Chicago'' model was sold by
Sears, Roebuck
Sears, Roebuck and Co. ( ), commonly known as Sears, is an American chain of department stores founded in 1892 by Richard Warren Sears and Alvah Curtis Roebuck and reincorporated in 1906 by Richard Sears and Julius Rosenwald, with what began a ...
for 73 cents in its catalog. In 1928, the name of the Markham company was changed to King Air Rifle Company after the company was purchased by Daisy in 1916 after decades of intense competition, and continued to manufacture the "King" model air rifle until 1935 before ceasing operation altogether in the 1940s.
During the 1890s, air rifles were used in
Birmingham, England
Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the West ...
for competitive
target shooting
Shooting sports is a group of competitive and recreational sporting activities involving proficiency tests of accuracy, precision and speed in shooting — the art of using ranged weapons, mainly small arms ( firearms and airguns, in forms su ...
. Matches were held in
public house
A pub (short for public house) is a kind of drinking establishment which is licensed to serve alcoholic drinks for consumption on the premises. The term ''public house'' first appeared in the United Kingdom in late 17th century, and was ...
s, which sponsored shooting teams. Prizes, such as a leg of
mutton
Lamb, hogget, and mutton, generically sheep meat, are the meat of domestic sheep, ''Ovis aries''. A sheep in its first year is a lamb and its meat is also lamb. The meat from sheep in their second year is hogget. Older sheep meat is mutton. Gen ...
for the winning team, were paid for by the losing team. The sport became so popular that in 1899, the
National Smallbore Rifle Association
The National Small-bore Rifle Association, the NSRA, is the national governing body for all Small-bore Rifle and Pistol Target Shooting in the United Kingdom, including Airgun and Match Crossbow Shooting.
The NSRA is based at The Lord Roberts C ...
was created. During this time, over 4,000 air rifle clubs and associations existed across
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
, many of them in Birmingham. During this time, the air gun was associated with
poaching
Poaching has been defined as the illegal hunting or capturing of wild animals, usually associated with land use rights.
Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set a ...
because it could deliver a shot without a significant
muzzle report.
Use
Air guns are used for
small game
Game or quarry is any wild animal hunted for animal products (primarily meat), for recreation (" sporting"), or for trophies. The species of animals hunted as game varies in different parts of the world and by different local jurisdictions, thou ...
hunting
Hunting is the human activity, human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products (fur/hide (skin), hide, ...
,
pest control
Pest control is the regulation or management of a species defined as a pest; any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the damage done and will range ...
, recreational
shooting
Shooting is the act or process of discharging a projectile from a ranged weapon (such as a gun, bow, crossbow, slingshot, or blowpipe). Even the acts of launching flame, artillery, darts, harpoons, grenades, rockets, and guided missiles can ...
(commonly known as
plinking
Plinking refers to informal target shooting done for pleasure, typically at non-standard targets such as tin cans, logs, bottles, or any other homemade or naturally occurring target.
Practice
In contrast to shooting done at established targe ...
) and competitive sports such as the
Olympic
Olympic or Olympics may refer to
Sports
Competitions
* Olympic Games, international multi-sport event held since 1896
** Summer Olympic Games
** Winter Olympic Games
* Ancient Olympic Games, ancient multi-sport event held in Olympia, Greece b ...
10 m Air Rifle and
10 m Air Pistol events.
Field Target (FT) is a competitive form of
metallic silhouette shooting
Metallic silhouette shooting is a group of target shooting disciplines that involves shooting at steel targets representing game animals at varying distances, seeking to knock the metal target over. Metallic silhouette is shot with large bore rif ...
in which the targets are animal-shaped steel
targets
''Targets'' is a 1968 American crime thriller film directed by Peter Bogdanovich, produced by Roger Corman, and written by Polly Platt and Bogdanovich, with cinematography by László Kovács.Stephen Jacobs, ''Boris Karloff: More Than a Monster' ...
with a "kill zone" cut-out.
Hunter Field Target (HFT) is a variation, using identical equipment, but with differing rules. The distances FT and HFT competitions are shot at range between for HFT & for FT, with varying sizes of "reducers" being used to increase or decrease the size of the kill zone. In the UK, competition power limits are set at the legal maximum for an unlicensed air rifle, i.e. . Air rifle benchrest is an international shooting sport where the objective is to hit a (small) bulls eye target at shooting distance. There are two divisions ARLV and ARHV .
The increasing affordability of higher-power pre-charged pneumatic (PCP) rifles has allowed large projectiles and further target distance for competition purposes. For instance, the Extreme Benchrest competition held annually in
Green Valley, Arizona
Green Valley is an unincorporated community and census-designated place (CDP) in Pima County, Arizona, United States. The population was 22,616 at the 2020 census.
Geography
Green Valley is located along the western side of the Santa Cruz Ri ...
allows calibers up to at 75 yd (68.58 m) while the Big Bore Benchrest arm of the same competition at other localities engages targets at .
Powerplant
The component of an airgun that provides the gas pressure needed to propel projectiles is called its ''powerplant''. which uses internally stored pressurized gas; and ''compressed gas'' (most commonly
CO2), which uses external sources of pressurized gas.
Spring-piston
![Air rifle collection 2](https://upload.wikimedia.org/wikipedia/commons/5/57/Air_rifle_collection_2.jpg)
A spring-piston air gun (also known as a spring gun or simply a "springer") operates by means of a
spring
Spring(s) may refer to:
Common uses
* Spring (season)
Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of ...
-loaded
piston pump
A piston pump is a type of positive displacement pump where the high-pressure seal reciprocates with the piston. Piston pumps can be used to move liquids or compress gases. They can operate over a wide range of pressures. High pressure operation ...
assembly contained within a compression chamber separate from the
gun barrel
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure ...
. Traditionally, a
grease-lubricated steel
coil spring
A selection of conical coil springs
The most common type of spring is the coil spring, which is made out of a long piece of metal that is wound around itself.
Coil springs were in use in Roman times, evidence of this can be found in bronze Fib ...
is used as the powerplant main spring. Before shooting, the user needs to manually cock the gun by flexing a lever connected to the pump assembly, which pulls the pump piston rearwards and compresses the main spring until the rear of the
piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...
engages the
sear
The Sahar Elevated Access Road, abbreviated to SEAR, is a dedicated, elevated, express access road in Mumbai that connects the Western Express Highway (WEH) near Hanuman Nagar junction in Vile Parle, with the forecourts of Terminal T2 of the C ...
. When shooting, the
trigger
Trigger may refer to:
Notable animals and people
;Mononym
* Trigger (horse), owned by cowboy star Roy Rogers
;Nickname
* Trigger Alpert (1916–2013), American jazz bassist
* "Trigger Mike" Coppola (1900–1966), American gangster
;Surname
* Bru ...
is pulled and disengages the sear, allowing the main spring to decompress and release its stored
elastic potential energy
Elastic energy is the mechanical potential energy stored in the configuration of a material or physical system as it is subjected to elastic deformation by work performed upon it. Elastic energy occurs when objects are impermanently compressed, s ...
, pushing the piston forward, thereby compressing the air in the pump cylinder. Because the pump outlet (located to the front of the pump) is directly behind the pellet seated in the barrel
chamber
Chamber or the chamber may refer to:
In government and organizations
* Chamber of commerce, an organization of business owners to promote commercial interests
*Legislative chamber, in politics
* Debate chamber, the space or room that houses delib ...
, once the air pressure has risen enough to overcome the
static friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of t ...
and/or barrel restriction holding back the pellet, the pellet is propelled forward by an expanding column of pressurized air. All this takes place in a fraction of a second, during which the air undergoes
adiabatic heating
In thermodynamics, an adiabatic process (Greek: ''adiábatos'', "impassable") is a type of thermodynamic process that occurs without transferring heat or mass between the thermodynamic system and its environment. Unlike an isothermal process, an ...
to several hundred degrees and then cools as the air expands. This can also cause a phenomenon referred as "dieseling", where flammable substances in the compression chamber (e.g., petroleum-based lubricant) can be
ignited by the compression heat like in a
diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...
, and lead to an
afterburner
An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and comba ...
effect with (often unpredictable) additional thrusts. This often results in combustion smoke coming out of the
muzzle and potential pressure damage to the rubber
O-ring
An O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more par ...
seal
Seal may refer to any of the following:
Common uses
* Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly:
** Earless seal, or "true seal"
** Fur seal
* Seal (emblem), a device to impr ...
s inside the gun. Dieseling can be made to occur ''intentionally'' to increase power, by coating the pellet with lubricant or
petroleum jelly
Petroleum jelly, petrolatum, white petrolatum, soft paraffin, or multi-hydrocarbon, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25), originally promoted as a topical ointment for its h ...
, although this is normally not recommended as it may result in a more severe damage to the rubber seals.
Most spring-piston guns are
single-shot
Single-shot firearms are firearms that hold only a single round of ammunition, and must be reloaded manually after every shot. The history of firearms began with single-shot designs, then multi-barreled designs appeared, and eventually many ce ...
breechloader
A breechloader is a firearm in which the user loads the ammunition (cartridge or shell) via the rear (breech) end of its barrel, as opposed to a muzzleloader, which loads ammunition via the front ( muzzle).
Modern firearms are generally breech ...
s by nature, but multiple-shot
repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some ...
s with
magazine
A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...
feeders have been introduced in recent years by manufacturers such as
Gamo,
Umarex
Umarex Sportwaffen GmbH & Co. KG is a German manufacturer of air guns (including Umarex air pistols such as the Beretta Elite II), tear gas, tear-gas and signal pistols, paintball markers under the RAM brand and airsoft guns, based in Arnsberg, No ...
and Hatsan.
![Air Pistol](https://upload.wikimedia.org/wikipedia/commons/a/ab/Air_Pistol.jpg)
Spring-piston guns, especially the high-powered "magnum" guns, are able to achieve muzzle velocities near or exceeding the
speed of sound
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At , the speed of sound in air is about , or one kilometre in or one mile in . It depends strongly on temperature as w ...
. The effort required for the cocking stroke is usually related to the designed power of the gun, with higher muzzle velocities requiring a stiffer spring and hence a greater cocking effort. Spring-piston guns have a practical upper limit of for
.177 cal (4.5 mm) pellets, as higher velocities cause unstable pellet flight and loss of accuracy. This is due to the extreme
buffeting
Aeroelasticity is the branch of physics and engineering studying the interactions between the inertial, elastic, and aerodynamic forces occurring while an elastic body is exposed to a fluid flow. The study of aeroelasticity may be broadly classi ...
caused when the pellet reaches and surpasses
transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transonic ...
speed, then slows back down and goes through
sound barrier
The sound barrier or sonic barrier is the large increase in aerodynamic drag and other undesirable effects experienced by an aircraft or other object when it approaches the speed of sound. When aircraft first approached the speed of sound, th ...
again, which is more than enough to destabilize the pellet's flight. Shortly after leaving the barrel, the supersonic pellet falls back below the speed of sound and the shock wave overtakes the pellet, causing its flight stability to be disrupted. Drag increases rapidly as pellets are pushed past the speed of sound, so it is generally better to increase pellet weight to keep velocities subsonic in high-powered guns. Sonic crack from the pellet as it moves with supersonic speed also makes the shot louder sometimes making it possible to be mistaken for firearm discharge. Many shooters have found that velocities in the range offer an ideal balance between power and pellet stability.
Spring guns are typically cocked by one of the following mechanisms:
* Break-barrel — like a
break action
Break action is a type of firearm action in which the barrel or barrels are hinged much like a door and rotate perpendicularly to the bore axis to expose the breech and allow loading and unloading of cartridges. A separate operation may be require ...
firearm, the barrel is hinged at the junction with the
receiver and is flexed downwards to expose the
breech
Breech may refer to:
* Breech (firearms), the opening at the rear of a gun barrel where the cartridge is inserted in a breech-loading weapon
* breech, the lower part of a pulley block
* breech, the penetration of a boiler where exhaust gases leav ...
and serves as the cocking lever
* Fixed-barrel – the barrel is fixed to the receiver, and the cocking is done with a separate cocking lever
** Underlever – the cocking lever is located underneath the barrel or the receiver and is flexed downwards during cocking
** Sidelever – the cocking lever is located to the side (usually the right side) of the receiver and is flexed sideways during cocking
** Overlever – the cocking lever is located above the barrel and is flexed upwards during cocking, seen in some air pistols
* Motorized cocking powered by a rechargeable battery (rare)
Spring-piston guns, especially high-powered ("magnum") models, do still
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, as according to Newton's third law the force requ ...
as a result of the mainspring pushing the piston forward. Although the recoil is less than that of some
cartridge
Cartridge may refer to:
Objects
* Cartridge (firearms), a type of modern ammunition
* ROM cartridge, a removable component in an electronic device
* Cartridge (respirator), a type of filter used in respirators
Other uses
* Cartridge (surname), a ...
firearms, it can make the gun difficult to shoot accurately as the spring recoil is in effect while the pellet is still within the barrel. Spring gun recoil also has a sharp forward component, caused by the piston hitting the front end of the pump chamber when the spring has fully decompressed. These rapid double-jerking movements are known to damage
scopes not rated for spring gun usage. In addition, the spring often has unpredictable collateral transverse vibrations as well as
torquing, both of which can cause accuracy to suffer. These vibrations can be controlled by adding features like close-fitting spring guides or by aftermarket tuning done by "air gunsmiths" who specialize in air gun modifications, a common one being the addition of viscous
silicone grease
Silicone grease, sometimes called dielectric grease, is a waterproof grease made by combining a silicone oil with a thickener. Most commonly, the silicone oil is polydimethylsiloxane (PDMS) and the thickener is amorphous fumed silica. Using this ...
to the spring, which both lubricates it and damps vibration. Some shooters hold the gun in a very loose grip (coined as the "artillery hold") that allows the gun to vibrate in a natural and consistent manner. There are also newer models with a floating receiver design that allows the
action
Action may refer to:
* Action (narrative), a literary mode
* Action fiction, a type of genre fiction
* Action game, a genre of video game
Film
* Action film, a genre of film
* ''Action'' (1921 film), a film by John Ford
* ''Action'' (1980 fil ...
to slide over the
stock
In finance, stock (also capital stock) consists of all the shares by which ownership of a corporation or company is divided.Longman Business English Dictionary: "stock - ''especially AmE'' one of the shares into which ownership of a company ...
autonomously, thus making the gun less hold-sensitive.
The better quality spring guns can have very long service lives, being simple to maintain and repair. Because they deliver the same mechanical energy output on each shot, external ballistics are quite consistent. Most
Olympic
Olympic or Olympics may refer to
Sports
Competitions
* Olympic Games, international multi-sport event held since 1896
** Summer Olympic Games
** Winter Olympic Games
* Ancient Olympic Games, ancient multi-sport event held in Olympia, Greece b ...
air gun competitions through the 1970s and into the 1980s were shot with spring-piston guns, often of the opposing-piston recoil-eliminating type. Beginning in the 1980s, guns powered by compressed/liquefied
carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
began to dominate the competition. Today, the guns used at the highest levels of competition are powered by
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
.
Gas spring
Some newer generation air guns incorporate a
gas spring
A gas spring is a type of spring that, unlike a typical mechanical spring that relies on elastic deformation, uses compressed gas contained within an enclosed cylinder sealed by a sliding piston to pneumatically store potential energy and withs ...
(commonly referred to as a ''gas piston'', ''gas ram'', ''gas strut'' or ''nitro piston'') instead of a mechanical spring. The spring itself is essentially a stand-alone enclosed
piston pump
A piston pump is a type of positive displacement pump where the high-pressure seal reciprocates with the piston. Piston pumps can be used to move liquids or compress gases. They can operate over a wide range of pressures. High pressure operation ...
without outlets and with pressurized air or
inert gas
An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to ...
(such as
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
) held tightly sealed within the
cylinder
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infin ...
. When the gun is cocked, the gas inside the cylinder gets further compressed by the piston, stores
potential energy
In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.
Common types of potential energy include the gravitational potentia ...
and acts in effect as a
pneumatic
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A central ...
accumulator. Gas spring units require higher precision to manufacture since they require a low-friction sliding seal that can withstand the high pressures within when cocked. The advantages of the gas spring include the ability to keep the gun cocked and ready to fire for extended periods of time without long-term spring
fatigue
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
, no twisting
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
(caused by coil spring expanding) exerted onto the gun, smoother recoil pattern and faster "lock time" (the time between pulling the trigger and the pellet being discharged), which all result in more consistent accuracy. Gas springs perform more reliably in cold climates than coil springs, because metallic coil springs need to be coated with
lubricating grease which often thickens in low temperatures causing the gun to "freeze up". Gas springs also have less lateral and longitudinal vibrations than coil springs, hence are usually less "hold-sensitive", making it easier to achieve consistent
shot grouping
In shooting sports, a shot grouping, or simply group, is the collective pattern of projectile impacts on a target from multiple consecutive shots taken in one shooting session. The ''tightness'' of the grouping (the proximity of all the shots to ...
s.
Pneumatic
![New Benelli Kite](https://upload.wikimedia.org/wikipedia/commons/2/26/New_Benelli_Kite.jpg)
Pneumatic airguns propel the projectiles by utilizing the
pneumatic potential energy within
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
, which is pressurized beforehand and stored inside the gun, and then released through valves during shooting. Single-stroke and multi-stroke pump guns utilize an on-board
hand pump
Hand pumps are manually operated pumps; they use human power and mechanical advantage to move fluids or air from one place to another. They are widely used in every country in the world for a variety of industrial, marine, irrigation and leis ...
to pressurize air in an internal reservoir, while pre-charged pneumatic guns' reservoirs are filled from an external source using either a high-pressure
stand pump or by decanting air from a larger
diving cylinder
A diving cylinder or diving gas cylinder is a gas cylinder used to store and transport high pressure gas used in diving operations. This may be breathing gas used with a scuba set, in which case the cylinder may also be referred to as a scu ...
.
Pump pneumatic
Pump pneumatic air guns, or pump guns, use a lever-operated onboard air pump to pressurize an internal reservoir, and then discharge the stored compressed air during shooting. Depending on the design, pump guns can be either single-stroke or multi-stroke.
* In ''single-stroke'' pneumatic air guns (also known as "single pump") a single motion of the cocking lever is all that is required to mechanically compress the air. The single-pump system has always dominated the casual plinking market, and is usually found in target rifles and pistols, where the higher muzzle energy of a multi-stroke pumping system is not required. Single-stroke pneumatic rifles dominated the national and international
ISSF 10 metre air rifle shooting events from the 1970s to the 1990s, until being outperformed by the introduction of pre-charged pneumatic (PCP) guns (discussed
below
Below may refer to:
*Earth
*Ground (disambiguation)
*Soil
*Floor
*Bottom (disambiguation)
Bottom may refer to:
Anatomy and sex
* Bottom (BDSM), the partner in a BDSM who takes the passive, receiving, or obedient role, to that of the top or ...
).
* ''Multi-stroke'' pneumatic air guns (also known as "multi-pump") use multiple pumpings to achieve variable power levels in order to adapt for both long or short-range shooting. These air guns are usually single-shot, where each shot requires approximately 5 strokes. However, up to five shots are possible, usually requiring approximately 10 to 20 strokes, as long as the air reservoir is capable of storing higher pressure. For safety reasons, most multi-stroke guns are usually designed to have their pump lever jam when the reservoir has reached its maximum pressure limit, so the user can no longer pump the gun until it's discharged. The maximum pressure limit for the reservoir is approximately 20 to 30 strokes.
Pre-charged pneumatic
Pre-charged pneumatic air guns (PCPs) have their internal reservoir pre-filled from an external air source (such as a
diving cylinder
A diving cylinder or diving gas cylinder is a gas cylinder used to store and transport high pressure gas used in diving operations. This may be breathing gas used with a scuba set, in which case the cylinder may also be referred to as a scu ...
or
air compressor
An air compressor is a pneumatic device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces ...
, or by manual charging with a high-pressure
stand pump), and remain pressurized until depleted after repeated shooting. During shooting, the hammer strikes the reservior's release valve, allowing a set volume of the pressurized air to be discharged into the chamber and propel the projectile. Depending on the release valve design, PCP air guns can be categorized into two types – ''unregulated'' and ''regulated'' (which has either a mechanical or electronic
regulator valve). In addition to
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
, custom PCP models using compressed pure
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
and even compressed
helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...
have also been recently developed.
Because of the need for cylinders or charging systems, PCP guns have higher initial costs but much lower operating costs when compared to CO
2 rifles, and have superior performance over ordinary pump guns. Having no significant movement of heavy mechanical parts during the discharge cycle, PCP airgun designs produce lower
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, as according to Newton's third law the force requ ...
, and can shoot as many as 100 shots per charge depending on the tank/reservoir size. The ready supply of air has allowed the development of semi- and fully automatic air guns. PCP guns are very popular in
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
because of their accuracy and ease of use. They are widely utilized in
ISSF 10 metre air pistol and rifle shooting events and the sport of
Field Target shooting, and are usually fitted with
telescopic sight
A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate po ...
s.
Early stand pump designs encountered problems of fatigue (both human and mechanical), temperature warping, and condensation – none of which are beneficial to accurate shooting or the airguns' longevity. Modern stand pumps have multi-stage chambers and built-in air filtration systems and have overcome many of these problems. Using
scuba
Scuba may refer to:
* Scuba diving
** Scuba set, the equipment used for scuba (Self-Contained Underwater Breathing Apparatus) diving
* Scuba, an in-memory database developed by Facebook
* Submillimetre Common-User Bolometer Array, either of two in ...
-quality air decanted from a diving cylinder provides consistently clean, dry, high-pressure air.
During the typical PCP's discharge cycle, the hammer of the rifle is released by the sear to strike the
bash valve
A bash valve is a valve within a piston engine, used to control the admission of the working fluid.[B ...](_blank)
. The hammer may move rearwards or forwards, unlike firearms where the hammer almost always moves forward. The valve is held closed by a spring and the pressure of the air in the reservoir. The pressure of the spring is constant, and the pressure of the air released (which is also known as the ''working pressure'') decreases with each successive shot. As a result, when the reservoir pressure is high, the valve opens less fully and closes faster than when the reservoir pressure is lower, resulting in a similar total volume of air flowing past the valve with each shot. This results in a degree of partial self-regulation that gives a greater consistency of velocity from shot to shot, which corresponds to the middle "plateau" phase of the gun's shot-to-shot
muzzle velocity
Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately to i ...
profile (also known as the ''power curve'' ). Well-designed PCP will display good shot-to-shot consistency over a long period, as the air reservoir is being depleted.
Other PCP rifles and pistols are regulated, i.e. the firing valve operates within a secondary chamber separated from the main air reservoir by the regulator body. The regulator maintains the pressure within this secondary chamber at a set pressure (lower than the main reservoir's) until the main reservoir's pressure drops to the point where it can no longer do so. As a result, shot-to-shot consistency is maintained for longer than in an unregulated rifle, and the gun can also output more shots due to reduced waste of reservoir pressure.
Compressed gas
![BB gun with CO2 and BBs](https://upload.wikimedia.org/wikipedia/commons/9/9e/BB_gun_with_CO2_and_BBs.jpg)
Compressed gas guns, also known as ''CG gun's, are essentially pneumatic airguns utilizing detachable
pressure reservoirs in the form of prefilled external
gas cylinder
A gas cylinder is a pressure vessel for storage and containment of gases at above atmospheric pressure. High-pressure gas cylinders are also called ''bottles''. Inside the cylinder the stored contents may be in a state of compressed gas, vapor ...
s (often with built-in
regulator valves), and are commonly referred to as ''CO
2 gun''s due to the ubiquitous commercial use of
bottled liquid carbon dioxide
Liquid carbon dioxide is the liquid state of carbon dioxide (), which cannot occur under atmospheric pressure. It can only exist at a pressure above , under (temperature of critical point) and above (temperature of triple point). Low-temperatu ...
. However, more recent high-end models sometimes use larger
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
/
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
(known as HPA or "N
2") cylinders, which have higher operating pressures and better thermal stability.
CO2
![Crossman-2240](https://upload.wikimedia.org/wikipedia/commons/c/c8/Crossman-2240.jpg)
CO
2 guns, like other pneumatic guns using compressed air, offer power for repeated shots in a compact package without the need for complex pumping or filling mechanisms. The ability to store power for repeated shots also means that repeating arms are possible. There are many replica revolvers and semi-automatic pistols on the market that use CO
2 power. Most CO
2 guns use a disposable cylinder called a "
Powerlet
Crosman Corporation is an American designer, manufacturer and supplier of shooting sport products, with a long-standing presence in airgun design and a tradition of producing pellet and BB guns. Crosman is also a producer of many varieties of ai ...
" cartridge, that is often purchased with of pressurized CO
2 gas, although some, usually more expensive models, use larger refillable CO
2 reservoirs like those typically used with
paintball marker
A paintball marker, also known as a paintball gun, paint gun, or simply marker, is an air gun used in the shooting sport of paintball, and the main piece of paintball equipment. Paintball markers use compressed gas, such as carbon dioxide (CO2) ...
s.
CO
2 guns are popular for training, as the guns and ammunition are inexpensive, relatively safe to use, and no specialized facilities are needed for safety. In addition, they can be purchased and owned in areas where firearms possession is either strictly controlled or banned outright. Most CO
2 powered guns are relatively inexpensive, and there are a few precision target guns available that use CO
2.
High-pressure air
High-pressure air
Paintball is an equipment-intensive sport and in order to safely conduct a game, every player requires a paintball marker, marker with propellant to fire the paint, a mask to protect the eyes and face, Paintball equipment#Paintballs, paintballs, a ...
(HPA) system, or ''N
2'', was originally developed for
paintball markers
A paintball marker, also known as a paintball gun, paint gun, or simply marker, is an air gun used in the shooting sport of paintball, and the main piece of paintball equipment. Paintball markers use compressed gas, such as carbon dioxide (CO2) ...
as a replacement for CO
2 cartridges, and uses Powerlet interface-compatible
diving cylinder
A diving cylinder or diving gas cylinder is a gas cylinder used to store and transport high pressure gas used in diving operations. This may be breathing gas used with a scuba set, in which case the cylinder may also be referred to as a scu ...
s filled with either pure
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
or
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
(which is 78% nitrogen). Because nitrogen is more
inert than CO
2, it remains in the
gas
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...
eous state longer when compressed; when it expands, it cools due to the
Joule-Thomson effect but at a far lower rate than
liquid CO2 because there is no change in
state
State may refer to:
Arts, entertainment, and media Literature
* ''State Magazine'', a monthly magazine published by the U.S. Department of State
* ''The State'' (newspaper), a daily newspaper in Columbia, South Carolina, United States
* ''Our S ...
from liquid to gas. This
thermostability
In materials science and molecular biology, thermostability is the ability of a substance to resist irreversible change in its chemical or physical structure, often by resisting decomposition or polymerization, at a high relative temperature.
...
reduces the variation in output pressure associated with rapid successions of firing cycles, improving accuracy and reliability in extreme climates. However, because compressed air is stored at higher pressures (up to ) than liquid CO
2 (stored at around ), HPA cylinders are more expensive. Cylinders smaller than may not even last as long as a standard CO
2 cartridge when subjected to frequent uses.
It is also possible to power an HPA-compatible gun directly from a plug-in
air compressor
An air compressor is a pneumatic device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces ...
without using a gas cylinder, though this type of setup is rare.
Air cartridge system
First developed in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
during the 1980s as the Saxby-Palmer Ensign, and then by Brocock as the "Brocock Air Cartridge System" (BACS) and later into the "Tandem Air Cartridge" (TAC),
this variation of the pre-charged pneumatic design have no pressure reservoir built into the gun, but instead use removable and reusable metallic
gas cylinder
A gas cylinder is a pressure vessel for storage and containment of gases at above atmospheric pressure. High-pressure gas cylinders are also called ''bottles''. Inside the cylinder the stored contents may be in a state of compressed gas, vapor ...
s often known as "Brocock cartridges" after its British manufacturer. Each air cartridge is essentially a self-contained gas reservoir housed inside a
cartridge case
A cartridge or a round is a type of pre-assembled firearm ammunition packaging a projectile ( bullet, shot, or slug), a propellant substance (usually either smokeless powder or black powder) and an ignition device ( primer) within a metal ...
(usually in the size of a
.38 Special
The .38 Special, also commonly known as .38 S&W Special (not to be confused with .38 S&W), .38 Smith & Wesson Special, .38 Spl, .38 Spc, (pronounced "thirty-eight special"), or 9x29mmR is a rimmed, centerfire cartridge designed by Smith & ...
), with an internal
bash valve
A bash valve is a valve within a piston engine, used to control the admission of the working fluid.[B ...](_blank)
designed to release the content when the base of the cartridge is struck. Prior to shooting, each cartridge is pre-filled with sufficient
compressed air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...
for one shot (typically via a multi-stroke
hand pump
Hand pumps are manually operated pumps; they use human power and mechanical advantage to move fluids or air from one place to another. They are widely used in every country in the world for a variety of industrial, marine, irrigation and leis ...
) and has a
.177/
.22 caliber .22 caliber, or 5.6 mm caliber, refers to a common firearms bore diameter of 0.22 inch (5.6 mm).
Cartridges in this caliber include the very widely used .22 Long Rifle and .223 Remington / 5.56×45mm NATO.
.22 inch is also a popular ...
pellet pre-seated to its front slot, and the entire cartridge is then inserted into a
chamber
Chamber or the chamber may refer to:
In government and organizations
* Chamber of commerce, an organization of business owners to promote commercial interests
*Legislative chamber, in politics
* Debate chamber, the space or room that houses delib ...
in the
gun barrel
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure ...
. When shooting, 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 nails into wood, to shape metal (as w ...
hits the rear of the air cartridge, mimicking the function of a
centerfire ammunition
Two rounds of .357 Magnum, a centerfire cartridge; notice the circular primer in the center
A centerfire cartridge is a firearm metallic cartridge whose primer is located at the center of the base of its casing (i.e. "case head"). Unlike rimf ...
. This allows the airgun to be constructed and operated in similar fashions to genuine firearms. It also allows for higher shot consistency because each cartridge can be easily filled to an identical air charge, essentially removing the "power curve" of conventional PCP guns and bypassing any need for
regulators. It also simplifies the magazine feed design and eliminates the risk of deforming the projectiles when the
action
Action may refer to:
* Action (narrative), a literary mode
* Action fiction, a type of genre fiction
* Action game, a genre of video game
Film
* Action film, a genre of film
* ''Action'' (1921 film), a film by John Ford
* ''Action'' (1980 fil ...
seats each pellet, as the soft lead pellet is protected from contact with the action probe by the harder cartridge casing.
The air cartridge system, both in the
rifle
A rifle is a long-barreled firearm designed for accurate shooting, with a barrel that has a helical pattern of grooves ( rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with ...
and
revolver
A revolver (also called a wheel gun) is a repeating handgun that has at least one barrel and uses a revolving cylinder containing multiple chambers (each holding a single cartridge) for firing. Because most revolver models hold up to six roun ...
forms, was at the peak of its popularity throughout the 1990s. The popularity of the Brocock range was such that, by 2002, estimates put the number of air cartridge guns in circulation around 70,000-80,000.
However, a small number of incidents relating to the alleged illegal conversion of (mainly) Brococks to
allow them to discharge live ammunition sparked a
media frenzy
Media circus is a colloquial metaphor, or idiom, describing a news event for which the level of media coverage—measured by such factors as the number of reporters at the scene and the amount of material broadcast or published—is perceived to ...
. In early 2002, the
BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
...
showed converted Brococks accounted for 35 per cent of all guns recovered by the police, and David McCrone, firearms adviser to the Association of Chief Police Officers and Deputy Chief Constable of
'' "there is evidence which would justify banning them". After the
in the United Kingdom. Brocock subsequently ceased production of all air cartridge systems and turned to focus primarily on PCP airguns.
. Lead is
(whether inhaled or swallowed), affecting almost every organ and system in the human body. For this reason, lead-free pellets are becoming increasingly popular, and are available in all major shapes and styles, just like traditional lead pellets.
By far the most popular shape is the
pellet, which has two sections – a solid front portion called the "head", which contains the
rear portion called the "skirt", which expands and fully engages the bore to provide a good
and thus allows maximal efficiency in pellet propulsion during shooting. In flight, the skirt has greater
-to-weight ratio than the head and exerts a rearward pull behind the center of mass, similar to that of a
. This produces a phenomenon known as ''drag stabilization'', which helps to counteract
. However, the diabolo shape also means that the overall pellet will have poor
tips. A variety of lead-free pellets are offered by all major pellet manufacturers, including H&N Sport, RWS, JSB, Gamo, and others. Since lead is very dense, it has a higher ballistic coefficient than lightweight alternatives such as tin, copper, or plastic. At the present time, the airgun industry does not mass-produce dense alternatives to lead with a high ballistic coefficient for long-range shooting.
" pellets for the more powerful modern PCP air rifles. Compared to the commonly used diabolo pellets, these slug pellets resemble
s and have more contact surface with the bore and hence need greater propelling force to overcome friction, but have better
barrel for spin stabilization in flight. They are also made of lead, and precautions should be taken when handling them, or preparing animals for food, as lead fragments can be easily missed inside the meat.
was once the most common airgun ammunition in the US, thanks to the popularity of
’s line of BB airguns. A BB is a small metallic ball in 4.5 mm/
, typically made of steel (with a copper or zinc coating) or lead. Originally called the "
s, which the first BB gun invented in 1886 was designed to shoot. Steel BBs can be acceptably accurate at short distances when fired from properly designed
barrels. Lead #3 buckshot pellets can be used in .25" caliber airguns as if they were large BBs.
Due to the hardness of the steel, steel BBs cannot "take" to rifled barrels, which is why they are undersized (4.4 mm ball against 4.5 mm bore) to allow them to be used in .177" rifled barrels, which when used in this configuration can in effect be considered
, but with a poorer gas-seal, and if 4.5 mm diameter BBs are used, they would jam in the bore. Therefore, steel BBs lack the spin stabilization required for long-range accuracy, and usage in any but the cheapest rifled guns is discouraged. The softer lead BBs however can be used in rifled barrels.
Typically BBs are used for indoor practice, casual outdoor plinking, training children, or to save money, as they are significantly cheaper than pellets. Replica pistols allow people to train with a BB gun, saving a lot of money to centerfire firearm cartridges. Care should be exercised to avoid
, and safety glasses are recommended. Recently, manufacturers have created
BBs, which break apart and do not ricochet, reducing the hazards associated with BB guns.
Some shotgunners use sightless BB rifles to train in
. Similar guns were also used briefly by the United States Army in a Vietnam-era instinctive shooting program called "
".
In the 18th and 19th centuries, air gun darts were popular, largely because they could be reused. Although less popular now, several different types of darts are made to be used in air guns, but it is not recommended that darts be used in air guns with
bores or in spring-powered air guns. Air guns that shoot darts are sometimes called ''dart guns'', and ''
) compounds.
Some modern air guns are designed to discharge arrows and are called ''arrow guns'' or sometimes ''airbows''. These arrows are designed with a hollow shaft that is open in the rear where the
would normally be. When loaded, the hollow arrow shaft is slid rearwards over a barrel whose external diameter is only fractionally smaller than the shaft's interior diameter, providing a close-enough fitting that minimizes rattling and gives a reasonable enveloping
. During shooting, the trigger releases high-pressure air from the barrel to the front portion of the hollow arrow shaft, pushing the arrow forward. Such air guns can shoot arrows at launch velocities rivalling or even exceeding high-end
, but they are also more expensive to set up and maintain.
event that replaced the traditional cross country run of 3,200 metres and timed air-pistol shoot. The competitors run 4 laps of 800 m combined with 4 rounds of firing. The pistols used are modified air pistols that fire an eye-safe laser beam towards a target at the same time as a discharge of air. This has made the organisation of the events easier from a safety point of view and allows competitors to travel more easily with their weapons.
(4.5 mm): the most common caliber. Mandated by the ISSF for use in international target shooting competition at 10m, up to Olympic level in both rifle and pistol events. It has also been adopted by most National Governing Bodies for domestic use in similar target shooting events. It has the flattest trajectory of all the calibers for a given energy level. At suitable energy levels it can be used effectively for hunting.
*
(5.5 mm & 5.6 mm): for hunting and general use. In recent years air rifles and pistols in .22" (and some other calibers) have been allowed for use in both domestic and international target shooting in events not controlled by the ISSF. Most notably in FT/HFT and Smallbore Benchrest competitions. These events often allow the use of any caliber air gun, up to a maximum which is often .22", rather than a fixed caliber.
Other less common traditional calibers include:
*
(5 mm): initially proprietary to the Sheridan multi-pump pneumatic air rifle, later more widely used.
*
(6.35 mm): the largest commonly available caliber for most of the 20th century.
*
(7.62 mm): the current largest available for non-PCP powered airguns
Larger caliber air rifles suitable for hunting large animals are offered by major manufacturers. These are usually PCP guns. The major calibers available are:
*
(0.79") or .87 (22.1 mm).
While in some countries air guns are not subject to any specific regulation, in most, there are laws which differ widely. Each jurisdiction has its definition of an air gun. Regulations may vary for weapons of different bore,
, or ammunition material. Guns designed to fire
weapons. There may be a minimum age for possession, and sales of both air guns and ammunition may be restricted. Some areas require permits and background checks similar to those required for propellant type firearms.
While historical air guns have been made specifically for warfare, modern air guns can also be deadly.
In medical literature, modern air guns have been noted as a cause of death. This has been the case for guns of caliber .177 and .22 that are within the legal muzzle energy of air guns in the United Kingdom.