Air gun

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Air rifle and Air pistol redirect here.
For the energy source used in reflection seismology, see Air gun (seismic).
For air guns designed to fire spherical projectiles, see BB gun.
For the Olympic shooting events, see 10 m Air Rifle and 10 m Air Pistol.
The Webley Xocet, a traditional break barrel, spring-piston air rifle

An air gun is a pneumatic gun which fires projectiles using compressed air or other high pressure gas as a propellant.

Contents

History

Air guns represent the oldest pneumatic technology having existed since the 15th century. At that time, they presented compelling advantages over the more primitive firearms of the day. For example, air guns could be fired in wet weather (unlike matchlocks) and with greater rapidity than the muzzle-loading guns of the period. Moreover, they were quieter than a firearm of similar caliber, had no muzzle flash and were completely smokeless, not disclosing the shooter's position on firing. Black powder guns of the 18th and 19th century produced huge volumes of dense smoke on firing, giving air rifles an advantage over them. One might also assume that the sound of an air gun would have been inaudible against the noise of a pitched battle.

For general usage air guns were not a real challenge to the dominant position of powder weapons. They were expensive, delicate, air reservoirs could burst explosively and the valves were not well sealed and slowly leaked pressure. Historical accounts mention common soldiers were often unable to handle the complex guns , this seems logical in an age where the average peasant recruit had never encountered a machine more complex than a horse-drawn cart. People who had any experience with mechanical devices (millers or clockmakers) were few and far between. The guns of the period were crude and required little skill by the infantryman.

During this period, France, Austria and other nations had special sniper detachments using air rifles. The Austrian 1780 model was named "Windbüchse" (literally "wind rifle") in German. The guns were developed in 1778 or 1779 <ref>Arne Hoff, Airguns and Other Pneumatic Arms, Arms & Armour Series, London, 1972</ref> by the Tyrolese watchmaker, mechanic and gunsmith Bartholomäus Girandoni (1744-1799) and are occasionally referred to as "Girandoni air guns" in literature (the name is occasionally spelled "Girandony"; "Giradoni" <ref>L.Wesley, Air Guns and Air Pistols, London 1955</ref> or "Girardoni" <ref>H.L.Blackmore, Hunting Weapons, London 1971</ref>. The Windbüchse (or the Girandoni Air Rifle) was about 4 ft (1.2 m) long and weighed 10 pounds (4.5 kg), which was about the same size and mass as a conventional musket of the time. The air reservoir was a removable, club-shaped butt. The Windbüchse carried twenty .51" (13 mm) lead balls in a tubular magazine. A skilled shooter could unload one magazine in about thirty seconds, which was a fearsome rate of fire compared to the slower muzzle loaders of the period. A shot from this air gun could penetrate a one-inch wooden board at a hundred paces, an effect roughly equal to that of a modern 9 mm or .45" caliber pistol.

Air gun developed by the Japanese inventor Kunitomo, circa 1820-1830.
Kunitomo air gun trigger mechanism.

Around 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") acquired from the Dutch in Dejima.

Air guns appear throughout other periods of history. The celebrated expedition headed by Lewis and Clark (1804) reportedly carried a .42" (10 mm) reservoir air gun, believed to be produced by Girandoni. It held 22 round balls in a tubular magazine mounted on the side of the barrel. The butt stock served as the air reservoir and had a working pressure of 800 PSI. The rifle was said to be capable of 22 aimed shots in one minute.

During the 1890s, air rifles were used in Birmingham, England for competitive target shooting. Competitions were held in, and between, public houses. Prizes, such as a leg of mutton for the winning team, were paid for by the losing team. The sport became so popular that just after the turn of the 19th century, a National Air Rifle Association was created. During this time over 4000 air rifle clubs and associations existed across Britain, many of them in Birmingham.

During this time, the air gun was associated with poaching due to the fact that it could deliver a shot at a relatively quiet level. A modern reproduction of an air cane copied accurately from one in the Royal Armouries, Leeds, UK by Baker and Currie <ref>Geoffrey Baker & Colin Currie, The Construction and Operation of the Air Gun Vol 2 The Walking Stick Air Gun, privately printed, 2003</ref> gives a performance of around 480 feet per second (ft/s) for a 51.5 grain 32 calibre lead ball. The reproduction was charged to 600 pounds per square inch and the first shot registered only 272 ft/s, indicating this is a realistic maximum pressure given that the release valve failed to open properly against the high pressure of air in the reservoir. The velocities were reasonably constant for the next five shots, after which they progressively diminished by about 20 ft/s per shot, though this figure is not exact. In an experimental simple home-made large calibre air gun with a three metre barrel Middleton obtained a maximum velocity of 599 ft/s for a 50 calibre 140 grain lead ball, and 411 ft/s from a 2 metre barrel with a .527 calibre 220 grain lead ball, using a pressure of only 100 pounds per square inch pumped with a bicycle pump <ref>Richard Middleton, The Practical Guide to Man-Powered Bullets, Merlin Unwin Books (UK) and Stackpole Books (US) 2005</ref>. Reilly, a London gunmaker specialising in air guns, writing around 1850 <ref>E.M.Reilly, Air Guns and other Air Weapons; a short pamphlet reprinted in 1995 by W.S.Curtis Publishers, Rhyl, Clwd</ref> states that he was able to produce a pressure of a little under 500 pounds per square inch using the direct stroke pump of the time. He does not give muzzle velocities. Wesley (op.cit., pp. 35-6) shot an antique air cane bullet of 3/4 inch diameter into the cast iron fireplace of his workroom, and demolished the fireplace, stripped the wallpaper off the walls, and blew all his oils and chemicals off the mantleshelf.

Today's modern air guns are typically low-powered due to safety concerns and legal restrictions; however, high-powered designs are still used for hunting. These air rifles can propel a pellet beyond 1100 ft/s (330 m/s), approximately the speed of sound and produce a noise similar to a .22 caliber rimfire rifle. Most low-powered airguns can be safely fired in a backyard or garden, and even indoors, with the proper backstop. In some countries, air guns are still classified as firearms, and as such it may be illegal to discharge them in residential areas. Air guns can be highly accurate and are used in target shooting events at the Olympic Games, governed by the International Shooting Sport Federation (ISSF).

Legal issues

The legal definition of an air gun differs from country to country; in the United Kingdom, for example, air pistols generating more than 6 ft·lbf (8.1 J) or air rifles generating more than 12 ft·lbf (16.2 J) of energy are considered firearms, as are air guns in Canada with a muzzle velocity of over 500 ft/s (150 m/s) and a muzzle energy in excess of 4.2 ft·lbf (5.7 J).

In Japan, any air gun that fires a metallic projectile is restricted as a firearm, so only airsoft type guns are readily available there. Many US cities and states restrict air gun sales and possession, usually independent of the power; these include: New York City, New York; New Jersey; Michigan; Chicago and Morton Grove, Illinois; San Francisco, California; and Philadelphia, Pennsylvania.

In the Philippines, airguns where the pellet penetrates a 1/4" must be registered with the Philippine National Police (PNP). Sales of airguns, irrespective of caliber or power, is restricted to shops authorized by the PNP. A separate permit to display airguns in a shop must be obtained as in the case of real firearms. However, in most provincial towns and cities, one can find airguns being sold in "unauthorized" hardware having neither a permit to deal or permit to display airguns. - BJCoson.

Even air guns not considered firearms are subject to regulation in most areas; at the very least they will be considered dangerous or deadly weapons. There are minimum ages for possession, usually less than the age for firearms. Sales of both air guns and ammunition may be restricted as well. Some areas may require permits and background checks similar to those required for firearms possession. In the UK, Brocock Air Cartridge System air guns, which use a precharged, single shot air cartridge (similar in size to a .38 Special cartridge) were banned after some pistols recovered by the police, were found to have been converted by criminals making them capable of firing rimfire ammunition or even .38 Special ammunition. <ref>BBC News Story</ref>

Air gun power sources

There are different methods of powering an air gun. These methods can be broadly divided into 3 groups - spring-piston, gas ram and pneumatic. These methods are used in air rifles and air pistols.

Spring-piston

An older, single shot, break barrel, spring-piston air rifle

Spring-piston air guns are able to achieve muzzle velocities near the speed of sound from a single stroke of a cocking lever or the barrel itself. The difficulty of the cocking stroke is usually related to the power of the gun, with higher muzzle velocities requiring greater cocking effort.

Spring-piston guns operate by means of a coiled steel spring-loaded piston contained within a compression chamber, and separate from the barrel. Cocking the gun causes the piston to be compressed until it engages the sear; pulling the trigger releases the sear and piston allowing it to move, compressing the air in the chamber directly behind the pellet. Once the air pressure has risen enough to overcome any static friction and/or barrel restiction holding the pellet, the pellet moves forward, propelled by an expanding column of air. All this takes place in a fraction of a second, during which the air undergoes adiabatic heating to several hundred degrees during compression, and then cools as the air expands once more.

Modern air gun lubricants are generally a compounded mix of ingredients, such as silicone paste and molybdenum disulfide. These compounds are designed to not burn at the temperatures reached in airgun compression chambers. Before the availability of synthetic lubricants, when petroleum based products were used, some writers claimed that upwards of 30% of the energy of the shot may have come from the burning or "dieseling" of some of the lubricant <ref> The Airgun from Trigger to Target. G.V. & G.M. Cardew 1995. 235 pp. Privately published. ISBN 0950510823 - ISBN-13 9780950510828 </ref> although this has been debated by others. The use of such combustible lubricants in modern guns, which are much more highly stressed, can severely damage the spring and piston seals.

Spring-piston guns seem to have a practical upper limit of 1200 ft/s (370 m/s) for .177 cal (4.5 mm) pellets. Higher velocities cause unstable pellet flight and loss of accuracy. 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.

Most spring piston guns are single-shot breech-loaders by nature (somewhat like a single or double barreled shotgun) but multiple-shot guns have been increasingly common in recent years. Spring guns are typically cocked by a mechanism requiring the gun to be hinged at the mid-point (called a break barrel), with the barrel serving as a cocking lever. Other systems that are used include side levers, under-barrel levers, and motorized cocking, powered by a rechargeable battery.

Spring guns, especially high-powered ones, have a significant recoil resulting from the forward motion of the piston. Although this recoil is less than that of a cartridge firearm, it can make the gun difficult to shoot accurately as the recoil forces are well under way while the pellet is still traveling down the barrel. Most guns seem to respond well to a light, repeatable grip that allows the gun to vibrate the same way from shot to shot. Spring gun recoil also has a sharp forward component, caused by the piston as it hits the forward end of the chamber when the spring behind it reaches full expansion. This sudden forward acceleration helps to counteract the backward recoil, since the backward and forward recoil forces happen within milliseconds of each other, but it is infamous for knocking around and loosening the lenses and reticles found in low and medium priced telescopic sights, even those which are designed to withstand the (backward-only) recoil from high-powered firearms. On any but the lowest power spring guns, any mounted telescope should be air gun rated.

Spring guns can also suffer from spring vibrations that can upset accuracy. These vibrations can be controlled by adding features designed into the gun, like close-fitting spring guides, or by aftermarket tuning done by 'airgunsmiths' who specialize in air gun modifications. A common modification is the addition of viscous silicone grease to the spring, which both lubricates it and damps out vibration.

The better quality spring air guns can have long service lives, often exceeding thirty years. Because they deliver the same energy on each shot, the trajectory is extremely consistent. This resulted in most Olympic air gun matches through the 1970s and into the 1980s being shot with spring-piston guns. Beginning in the 1980s, guns powered by compressed, liquefied carbon dioxide began to dominate competition. Today, the guns used at the highest levels of competition are powered by compressed air stored at very high pressures of 2000 to 3000 lbf/in² (14 to 21 MPa).

The Chinese army uses spring-piston small arms to train more economically. These military-issue Chinese spring-piston air-guns are often available by mail-order, but the buyer should note that quality control on these guns tends to be somewhat variable. Similarly, the Romanian army formerly used spring-piston, single shot, 4.5 mm training rifles to train entry level recruits, prior to switching them to .22 LR training rifles.

The Theoben Evolution, a break barrel gas-ram air rifle

Some makes of air rifle (e.g. Weihrauch, Theoben) incorporate a gas-ram instead of a mechanical spring. Pressurized air or nitrogen is held in a special chamber built into the piston, and this air is further pressurized when the gun is cocked. It is, in effect, a gas spring more commonly referred to as a "gas-ram" or "gas strut". Gas-ram rifles require higher precision to build, since they require a low friction sliding seal that can withstand the high pressures when cocked. The advantages of the gas-ram include the facility to keep the rifle cocked and ready to fire for long periods of time without harming the mechanism. Also, due to the absence of a spring (and therefore a reduction in moving mass during firing) there is less (although some say slightly sharper), recoil. There is also an elimination of the associated problems of long-term spring fatigue and a faster "lock time" (the time between pulling the trigger and the pellet being discharged). The improvement in lock time makes for better accuracy due to there being less time for the gun to move off target.

Pneumatic

Pneumatic-type airguns require the pre-compression of air in a chamber prior to the gun being used. Single-stroke and multi-stroke guns utilize an on board pump, while PCP guns use either a high-pressure hand pump or air compressor to pressurize the air. When fired, the compressed air in the chamber is used to force the projectile out. Due to this design, the amount of recoil is almost zero as there is no significant movement of mechanical parts during the firing cycle. These air guns may also be powered by CO2 stored in capsules or cylinders, and filled via a hand pump or dive tank.

Multi-stroke

The Crosman Classic 2104X, a typical multi-stroke air rifle

Multi-Stroke pneumatic air guns require 2-10 pumps of an on-board lever to store compressed air within the air gun. Variable power can be achieved through this process, as the user can adapt the power level for long, or short-range shooting. The design of higher quality and match-grade multi-stroke air rifles can propel a pellet to speeds in excess of 1000 feet per second.

For beginners and intermediates, multi-stroke air rifles have been a cost-effective choice as they are generally the cheapest form of air gun available. Several manufacturers make multi-stroke air guns including, to name a few, Sheridan, Benjamin, Daisy, and Crosman. Modified multi-pump guns, with stronger pump linkages and improved valves, can produce muzzle energies in excess of 30 foot-pounds from inexpensive guns. Modification kits for Sheridan and Benjamin rifles are available from commercial suppliers.

In the Philippines, especially in the provinces, the multi-stroke foot pump airgun remains quite popular. Just imagine a bicycle or PCP pump attached below the air tank. This is similar to the Paul Model 420 (circa 1924). Companies that are still producing these foot pump airguns are Philcolt and Eskopeta. Estella-Parco, a pioneer, is reportedly interested in going back into footpump production. Others that have closed down is Garco. - BJCoson.

Single-stroke

As the name implies, one motion of the cocking lever is all that is needed to compress the air for propulsion. The single-pump system is usually found in target rifles and pistols, where the higher muzzle energy of a multi-stroke pumping system is not required.

Pre-charged Pneumatic

The Daystate MKIII, a pre-charged pneumatic air rifle. Note: The air reservoir (cylinder) is visible beneath the rifle's barrel)

Pre-charged pneumatic (PCP) airguns can be used for hunting and competition. These are usually filled by decanting from an air reservoir, such as a diving cylinder or by charging directly with a hand pump. Because of the need for cylinders or charging systems, PCP guns have higher initial costs but very low operating costs compared to CO2 guns. These guns are often used for hunting purposes in countries other than the U.S. because of restrictive firearm laws.

PCP guns were the very first air guns; an experimental gun was made for King Henry IV of France in 1600 . The Austrian military issued air rifles designed by Girandoni to special troops in the late 19th century.

PCP guns have very low recoil and can fire from fewer than 30, to as many as 500 shots per charge. The ready supply of gas, has allowed the development of semi-automatic PCP air guns. Though technology allows this design, these types of PCP airgun are not permitted in certain countries, e.g. the United Kingdom. PCP guns are very popular in the UK and Europe due to their accuracy and ease of shooting. They are widely utilized in the sport of Field Target shooting, <ref>American Airgun Field Target Association</ref> and fitted with telescopic sights.

PCP guns are frequently used for hunting. In some countries, the use of a sound moderator or silencer makes these rifles particularly quiet, an advantage for hunters. Modern reservoir guns in larger calibers (6 mm to 9 mm) are often used for hunting small game in the U.S.

Earlier hand pumps for charging carried with them problems of fatigue (both human and mechanical), temperature warping, and condensation. None of those is beneficial to good shooting or the longevity of the rifle. More modern design hand pumps with built-in air filtration systems overcome many of these problems. Using scuba-quality air decanted from a scuba cylinder provides a clean, dry, high-pressure air supply that is consistent and available at low cost.

During the discharge cycle, the hammer of the rifle is released by the sear to strike the valve. This usually involves the hammer moving toward the rear of the rifle, unlike firearms where the hammer normally moves forward. Prior to being struck by the hammer, the valve is held closed by a spring and the pressure of the air in the air gun's tank. The pressure of the spring is constant, and the pressure of the air changes with each successive shot. As a result, when the tank pressure is at its peak, the valve permits passage of less total volume of air than when the tank pressure has been reduced by a series of shots. This results in a somewhat greater consistency of velocity from shot to shot than would otherwise be expected, and accuracy with a rifle is mainly dependent on consistency.

The PCP is valuable to the small game hunter, pest controller, dedicated target shooter, marksmanship instructor and any other who requires precision, rather than the firepower of a firearm.

CO2

The Crosman 2260, a typical CO2 air rifle.

Most CO2 guns use a disposable cylinder, a powerlet, that is purchased pre-filled with 12 grams of liquefied carbon dioxide, although some, usually more expensive models, use larger refillable CO2 reservoirs like those typically used with paintball markers.

Carbon dioxide-powered guns have two significant advantages over pre-charged pneumatic air guns: (1.) A simpler system for compact storage of energy - a small volume of liquid converts to a large volume of pressurized gas. (2.) No pressure regulator. Within a temperature range tolerable to humans there is little need to regulate the inherently suitable pressure for low-to-moderate-power air guns. The vapor pressure is dependent only on temperature, not tank size, as long as some liquid CO2 remains in the reservoir.

These two advantages allow CO2 guns to be constructed more simply than guns using a pressurized air reservoir. Some CO2-powered guns have detachable or fixed reservoirs that are loaded with pressurized gas from a larger cylinder. Most CO2 powered guns use the standard 12 gram Powerlet disposable cylinder invented by Crosman. Recently, the same company introduced a new 88 gram disposable AirSource cylinder that is used in some of their guns.

CO2 guns, like compressed air guns, offer power for repeated shots in a compact package without the need for complex cocking 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 CO2 power. These guns are popular for training, as the guns and ammunition are inexpensive, 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 CO2 powered guns are relatively inexpensive, although there are still a few precision target guns on the market that use CO2.

The CO2 system has been used in experimental non-lethal law enforcement weapons, where high power delivery systems launch rubber batons or bean bags out of a gas-powered launcher, much like a non-lethal shotgun system (but at lower velocities, thus being safer).

Safety

For safety, CO2 containers must be kept at temperatures below 120 °F (49 °C) ; at temperatures above this level, the pressure begins to increase very rapidly, and can cause the container to fail. CO2 containers with diameters at or above two inches (50 mm) have a pressure release "rupture" mechanism to release the contents over a certain pressure level and avoid explosion due to high temperature. These disks are generally calibrated to a minimum pressure corresponding to the 120 °F level at 100% of the rated CO2 capacity. Elevated temperatures, even those below the critical temperature, can cause increased leaking through seals.

Operating considerations

  • Re-filling Forcing more carbon dioxide gas into a reservoir of liquid and gas CO2 while maintaining a constant temperature would not raise the pressure but merely convert the additional gas into liquid. By chilling the vessel to be filled, the lower vapor pressure will pull CO2 from the source container. While the pressure in the reservoir is generally dependent only on the temperature, if the bottle is too full, that changes. The expansion of the liquid CO2 will take up all the space in the bottle, preventing evaporation. At this point, the pressure increase with temperature becomes dangerously high. <ref>World And Regional Paintball Information Guide</ref>
  • Cooling Each time the gun is fired there is some evaporation of liquid to gas which is an endothermic process in which the pressure drops until enough ambient heat is absorbed to restore the pressure. When shooting at a rate faster than the cylinder can absorb heat from the environment to counter the cooling of the evaporating liquid, the pressure will drop, and the velocity is likely to drop as well in a non-regulated gun.

Calibers

The most common pellet calibers

Air guns are most commonly found in the following calibers:

  • .177" (4.5 mm) - the most common caliber, also used in ISSF shooting events at the Olympic Games, it has the flattest trajectory of all the calibers, making accuracy simpler.
  • .20" (5.0 mm) - found in some European air guns and those manufactured by US air gun manufacturer, Sheridan. This is generally considered to be a 'compromise calibre', having a flatter trajectory similar to the .177 but more energy retention.
  • .22" (5.5 mm & 5.6 mm) - the most common caliber for hunting small game, as it delivers large amounts of energy on impact (more so than the smaller calibers).
  • .25" (6.35 mm) - the largest commonly available caliber. This caliber is renowned for its impact, having the most energy retention of all calibers. However, it does have a highly parabolic trajectory and is more commonly used with higher powered rifles.

Ballistic modeling software is able to illustrate the benefits and disadvantages of each calibre at various power levels.

Larger calibers do exist, for example a Korean manufacturer sells air rifles in .36" (9 mm) and larger . Custom airgun manufacturers regularly produce air rifles in common muzzleloading rifle calibers too, such as .45" (11.25 mm), .50" (12.5 mm), .58" (14.5 mm) and larger. These large bore air guns are made by several custom Airgunsmiths, for example US air gun manufacturer Dennis Quackenbush. Quackenbush rifles have been used to kill many types of large game including Elk, and African game species up to Kudu. Gary Barnes is another large bore air gun manufacturer, whose handmade air guns are suitable for hunting medium sized game.

Ammunition

A .177 caliber "Wadcutter" pellet next to a stick of gum.

Pellet

Main article: Pellet (air gun)

The typical projectile used in rifled air guns is the lead diabolo pellet. This is a waisted projectile hollowed at the base and available in a variety of head styles. The diabolo pellet is designed to be drag stabilized, though is not as stable as some other shapes in the transonic region.

While some high-power Spring-piston air rifles can propel light pellets at, or beyond, the speed of sound, this results in decreased accuracy and often decreased life of the rifle's spring and seals. This is due to a lighter pellets tendency to move along a barrel before maximum pressure is reached, resulting in loss of the 'air cushion' and subsequent collision of the piston and/or seal into the end of the air chamber at high velocity.

Most air guns have a caliber of .177 (4.5 mm) or .22 (5.6 mm), and are designed for target practice, small game hunting and field target shooting. Cost per round is less than $0.02 (US) for Olympic-quality ammunition, and far less for cheaper grades. Though less common, .20 and .25 caliber (5.0 mm and 6.4 mm) guns also exist and are used predominantly for hunting.

Most air rifle pellets are made from lead which is harmful to the body if it is inhaled, ingested, or enters the bloodstream. Over exposure to this substance may cause lead poisoning. Shooters should ensure that measures are taken to prevent lead from entering the body, such as washing hands and avoiding lead dust. If these measures are taken, lead is very safe for use as a projectile. There are non-toxic pellets available, such as tin or steel-tipped plastic, which are safe to handle and don't deposit lead into the environment.

BB

.177 calibre steel BBs

The BB was once the most common air gun ammunition in the USA. A BB is a small ball, typically made of steel with a copper or zinc plating. Lead "Round Balls" are manufactured in numerous calibers too, however these are more appropriate for use in .177 caliber rifled guns normally used for shooting pellets. Steel BBs can be very accurate at short distances when fired from properly designed BB guns, however when fired from smoothbore barrels they lack the spin stabilization required for long-range accuracy.

Typically BBs are used for indoor practice, casual outdoor plinking, training children, or for air gun enthusiasts who like to practice, but cannot afford high-powered air gun systems that use pellets. Some shotgunners use sightless BB rifles to train in instinctive shooting. Similar guns were also used briefly by the United States Army in a Vietnam-era instinctive shooting program called "Quick Kill" (Time Magazine, Friday, Jul. 14, 1967).

Choosing an air gun

The following table provides general guidelines for choosing an air gun for a desired feature.

Feature Airgun Types Comments
Self-Containment spring-piston, multi-stroke pneumatic, single-stroke pneumatic These guns require no additional CO2 cylinders or external pumps, and are thus cheaper to operate.
Low Noise spring-piston Absence of loud gas discharges makes these guns quieter to operate. Consider when practicing in cramped urban areas. Where legal, a good quality suppressor (commonly referred to as a silencer or moderator) can make other types as quiet as a piston rifle.
Accuracy pre-charged, single-stroke pneumatic, recoilless piston Without the variable factor introduced by CO2 vapor pressure or the recoil introduced by the spring, the mechanisms in these guns have more repeatable shots.
Convenience pre-charged or CO2 powered These guns don't require constant cocking, and are hence more popular with recreational shooters. They are generally more expensive to operate.

While the above generalizations are helpful, the performance of an air gun will also depend on its quality. For example, a match-grade CO2 rifle will have better accuracy than a cheaper spring-piston gun. The extra costs of a more expensive gun may translate into higher quality, tighter tolerances, and better accuracy.

It is also important to consider where (e.g. club range, backyard, farm) and how (e.g. competition, target practice, plinking, pest-control) an air gun will be used.

See also

References

<references/>

External links

Safety
Animations / Demonstrations
Ballistic Modeling software
History
Manufacturers
Custom Manufacturers
Hand Pumps and Compressors
Reviews
Clubs and Special Interest Groups

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