Question: What do airsoft guns shoot?

Airsoft gun




Airsoft guns are replica weapons used in airsoft sports. They are a special type of very low-power smoothbore air guns designed to shoot non-metallic spherical projectiles often colloquially (and incorrectly) referred to as "BBs", which are typically made of (but not limited to) plastic or biodegradable resin materials. Airsoft gun powerplants are designed to have low muzzle energy ratings (generally less than 1.5 J, or 1.1 ft⋅lb) and the pellets have significantly less penetrative and stopping powers than conventional air guns, and are generally safe for competitive sporting and recreational purposes if proper protective gear is worn.
Depending on the design mechanism for pellet propulsion, airsoft guns can be categorized into two groups: mechanical, which consists of a coil spring-loaded piston air pump that is either manually cocked (e.g. spring guns) or automatically cycled by an additional battery-powered electric motor gearbox (e.g. AEGs); and pneumatic, which operates by valve-controlled release of prefilled bottled gas such as compressed Green Gas or CO2 canisters (e.g. GBB guns).
As toy weapons, airsoft guns can often be designed to realistically resemble genuine firearms in appearance, and it can be very difficult to distinguish from one visually, despite their orange tips in some jurisdictions. Airsoft guns cannot be modified into real firearms that shoot lethal ammunition despite the similar appearance.[1]

Manufacturers
Currently, a large army of airsoft manufacturers are on the market,[2] these include 6mm Proshop, AGM, ARES, ARMORER WORKS(WE Tech is the OEM)ASG, A&K, APS, Army Armament, ATS, BG Tactical, Bolt, Both Elephant, Classic Army, C-TAC, CYMA, Cybergun, D-Boys, DeepFire, Double Eagle, DYTAC, E&L, Echo 1, EMG, T.I.E.R., G&G Armament, G&P, GHK, Ho Feng Corp, ICS, Jing Gong, Jin Peng, Galaxy, King Arms, KJ Works, Krytac, KWA (which is OEM for KSC), KWC, Lancer Tactical, Lonex, Lucid, Mad Bull Airsoft, LCT, Marushin, Maruzen, Magpul PTS, Matrix, Modify, Polarstar, Pro Arms, RWA, Salient Arms, Silesia Factory, SRC, Systema Engineering, Tokyo Marui, Tanaka Works, Umarex (Elite Force), Umbrella Armory, VFC, WE Tech, Wei-E Tech, Well, Western Arms, Crosman, and WinGun.[3][4]
Other companies, such as Aftermath, Crosman, Echo 1, Matrix, and UTG, re-brand and distribute guns, sometimes with other accessories in countries where some manufacturers may not have an established distribution network.
Many of the best-selling airsoft guns are highly detailed replicas of real firearms, which are manufactured and designed by companies headquartered in East Asia such as Japan, Taiwan, South Korea, Hong Kong and China, however, European and North American brands exist also. Beyond airsoft guns proper, those companies may produce other items like BBs, airsoft grenades and airsoft landmines (like Airsoft Innovations and S-Thunder), as well as spare parts and a varied range of accessories for the replicas, like scopes, mounts and suppressors.
A subculture of high performance airsoft guns has created a big influence globally. Companies such as Umbrella Armory, Polar Star, & Systema have all brought high performance airsoft guns to the industry. Many traits are high fire rate, far distance reach, consistent and accurate firing. These features are not common on most retail airsoft guns and often so prices for these products tend to be very costly.
Usage



Airsoft in the past was used almost solely for recreational purposes, but in 2012, gas blowback (GBB) airsoft technology became adopted by US federal and state institutions as an affordable and reliable tactical training tool for close quarters battles. The GBB guns allowed for correct weapon manipulation drills, muscle memory training, stress inoculation and force-on-force simulations for a fraction of the cost of conventional bolt conversion kits that use marking cartridges from training ammunition manufacturers such as UTM and Simunition. Airsoft guns also allow basic and advanced shooter training in a safer environment by reducing the risks of accidental injury or death from a negligent discharge.
There are clubs, teams and even athletic associations devoted to airsoft events around the world. Europe is home to some of the largest events, with skirmishes of over 2,000 people participating. In North America, in 2012 alone, Fulda Gap Airsoft Game in Taylorsville, North Carolina had over 1,100 participants, and Operation Lion Claws Military Simulation Series (OLCMSS) had 800 people attend at George Air Force Base in Victorville, California. American Mil-sim, Black Sheep, and Ballahack also host large games. The attraction of the larger games is due to the intensity and variety in equipment that is used, ranging from small arms to armored vehicles.
In many countries, every airsoft gun owner and active enthusiast must be affiliated with an accredited airsoft association or federation. Most airsoft players host games at a registered field where combat situations are simulated using airsoft weaponry like replica pistols, submachine guns, carbines/assault rifles, DMRs/sniper rifles, light machine guns, grenades and landmines. Great variety and profusion of militaria is usually used. Historical reenactment of famous war situations is another favorite of many airsoft players and clubs. In addition, a number of companies such as Systema Engineering and Celsius Technology manufacture ultra-realistic high-velocity airsoft rifles designed specifically for the police and military for non-lethal training purposes. People today can also use it as props for film making.
Types of airsoft guns
Spring-powered
Spring-powered airsoft guns (or "air-cocking guns" as called by Tokyo Marui) are single-shot devices that use the elastic potential energy stored within a compressed coil spring to drive a piston air pump, which is released upon trigger-pull and rapidly pressurizes the air within the pump cylinder to in turn "blow" pellets down the gun barrel.  These guns are almost identical (though simplified) in design to spring-piston air guns and have the same operation principles. The user must manually recompress the spring under stress prior to each shot, typically by pulling back the slide (pistols), bolt handle (rifles) or forend pump (shotguns) on the weapon, which cocks and readies the gun.  Because of this, spring guns are incapable of automatic or semi-automatic firing by design.
Spring-powered airsoft guns are generally not as powerful as gas-powered ones, but are more powerful than electric airsoft guns because stiffer springs can often be used without the worry of overloading any motor-gearbox, although some spring shotguns and bolt-action rifles can be very powerful with muzzle velocities up to 400–700ft/s (120–210m/s). Spring guns are generally inexpensive (except the high-power sniper rifles and shotguns), and may not last long (depending on the build quality) due to the tension exerted on the gun parts by the recoiling of a powerful spring. However, many spring guns can be modified and upgraded to last longer and shoot more powerfully.
While most electric airsoft guns also use springs to drive the air pump and propel the pellets, they use external power sources and are not considered to be in the same category as the single-shot manual spring guns. Low-end spring guns tend to be much cheaper than their electric equivalents due to their simplicity and lack of electrical components (electric motor/actuator, spring-gearbox assembly, as well as battery and battery charger) and thus are widely available. These guns are less suited for competition because they are at a rate-of-fire disadvantage against automatic guns in close combat and do not provide enough accuracy and power for long-range use. There are some exceptions, however, as higher-end spring-powered airsoft rifles can be quite expensive; these guns are typically suited for "marksman" applications in airsoft matches and provide competitive muzzle velocities. Additionally, pump shotguns are sometimes used for both short and longer range engagements. In colder weather, spring pistols are more reliable than gas-powered pistols and even the batteries on automatic electric pistols (AEPs) both of which can be adversely affected by extreme low temperatures. This represents one of the major advantages of spring airsoft gun, as it can be fired in practically any situations without relying on batteries or bottled gas. This independence from external power sources causes some players to favor spring-powered guns. Spring guns are also less susceptible to the effects of water, where a battery-powered gun could short-circuit and malfunction when wet.
Spring-powered weapons are often cheaper than electric or gas-powered weapons. They are also more readily available in most department stores.  Because of their low price, availability and simplicity, spring guns tend to act as "training guns" to bring new players to airsoft games and are considered the primary weapon of "backyard skirmishes". In the UK, they are affectionately known as "springers" and were often a player's introduction to the sport due to the entry-level cost in comparison to AEG and GBB weapons. Almost all airsoft players at some point owned a spring weapon, whether for its actual use in a competitive event or for the replica value since some airsoft weapons are only available as spring versions. However, some veteran airsoft players still rely on sniper rifle and shotgun-type spring guns as a primary weapon due to their reliability, high power, high accuracy and low noise, as well as their ease of repair and modification compared to AEGs and GBB guns.
To be eligible to purchase a spring-powered airsoft gun in the United States, a person has to be of at least 10 years of age.
Battery-powered 
Automatic electric guns



Electrically powered airsoft guns use a spring-loaded piston pump just like spring guns, but instead of manual operation they typically use portable rechargeable battery packs to power an internal electric motor, which transmit through a gearbox to compress the pump spring and propel/load the pellets in a cyclic fashion. Selective fire options among automatic, 3-round burst and semi-automatic operations are all possible, which gives these guns the popular name "automatic electric guns", or AEGs.[5] These guns often attain muzzle velocities from 150 to 650ft/s (46 to 198m/s) and rates of fire (RoF) between 100 and 1500 rounds per minute. They are the most commonly used and widely available type of airsoft gun.
The AEGs were developed in Japan and the Japanese company Tokyo Marui is credited with creating the original gearbox system. In a Tokyo Marui AEG, the motor drives a train of three gears mounted inside a gearbox, which then loads a pump piston against a spring. Once the spring is released, it pushes the piston plunger forward through the pump cylinder to propel a pellet resting within the chamber forward through the barrel and out of the muzzle. Many manufacturers have now more or less replicated this basic model, adding reinforced parts or minor improvements.
The electric airsoft guns were powered primarily by nickel-metal hydride (NiMH) batteries with varying voltages and milliampere-hour ratings. The most common battery is an 8.4V large battery pack, with a capacity between 2200 and 5000 mAh. Also available are "mini" and "stick" batteries, which generally have 900 ~ 1600mAh capacities. Voltages for NiMH batteries range from 7.2V to 12V. The usual rule of thumb is that the higher the mAh rating, the longer the battery lasts; the higher the voltage, the higher the rate of fire.[6] Recently, however, the more energy-dense lithium polymer (Li-Po) batteries are becoming more popular in the airsoft world, since they last longer, have higher mAh and voltages, and can be charged more frequently without concerns for voltage depression, while at the same time being small and lightweight. Li-Po batteries are usually rated at 7.4V or 11.1V, and varying between 500mAh and 6500mAh.
External modifications, such as metal bodies and reinforced plastics that make AEGs look and feel even more realistic, have become very popular.  AEG manufacturers such as Classic Army and Tokyo Marui produce replicas that are visually nearly identical to their real counterparts. Tokyo Marui uses an ABS plastic, whereas Classic Army features full metal bodied guns and stronger furnishings. Most AEGs produced as of late are designed to be as visually realistic as possible.
The three most common AEGs on the field are the AR-15 series (such as M16 rifle, M4 carbine, etc.; sometimes referred to as the ArmaLite or Colt series), the H&K MP5 series, and the AK or Kalashnikov series. Also increasing popular is the H&K G36 and more recently, FN P90 and H&K MP7.  Subsequently, numerous parts for repairs and modifications are commonly available for these rifles. AEG models range from a simple pistol to a rocket propelled grenade all the way to a minigun.
Low powered electric guns

Some airsoft guns are called low powered electric guns (LPEGs) to distinguish them from the original, more expensive and more powerful AEGs even though their mechanical/electrical design and operation is similar. They are not to be confused with mini electrics (described below). Originally they were only of novelty value, often regarded below spring-operated guns due to their construction and low velocities. Since there are spring action guns that can notably outperform the true low-end LPEGs and can be found at comparable prices, they are generally considered to be better choices.
Medium price electric guns
Some companies – like UTG with their popular MP5 and AK-47 models – have improved their quality to such an extent that some models are now considered simply as mid-ranged AEGs that are more affordable but still reasonably effective. Among airsofters, these are commonly called middle priced electric guns (MPEGs). Sometimes, MPEGs are copies or 'clones' of designs by full-price manufacturers like Tokyo Marui.  As of late 2008 a small number of MPEG brands such as Echo-1/Jing Gong, and CYMA are considered by many to approach the quality and match the performance of the originals, at less than half the price. "Fully compatible" MPEGs imitate the Marui or Classic Army originals so precisely that standard upgrade parts will work with them, making it possible to hot-rod an MPEG to well beyond stock out-of-the-box AEG performance.
Electric blowbacks
Electric blowbacks, also known as EBBs, are high-end AEGs which generally run from a rechargeable 9.6 volt battery. Most models utilizing this system are rifles. EBBs simulate the blowback action of a real pistol or rifle but generally have less of a kick. Essentially an AEG in design, EBBs are just as powerful. However, a drawback to having the blowback feature is that the battery is quickly depleted, additionally blowbacks can cause extra stress on the gear box which may result in the gearbox's shorter life span. The blowback system can be disabled with some tinkering.
Electric blowback can also refer to a feature in some higher-end guns which offers more realistic operation. Companies such as G&G now offer guns such as the combat machine M4 and the combat machine "RK47" which has moving parts linked directly to the main mechanism of the gun, such as the bolt. Echo 1 has recently released a Blowback MP5SD. Also, APS (Accuracy Pneumatics Shooting) makes EBB M4A1, M4 Commando, and the AK47. The M4s also have three others with an RIS unit. These weapons perform identically to similar non-blowback offerings, with the added realism of reciprocating bolts and some recoil. Most models incorporate pneumatic blowback systems but some feature mechanical systems.
Mini electrics
Recently, the company Well, well known for its spring guns, began manufacturing a range of battery-powered guns in miniature size that fire only full automatic. They differ from GPMGs in that they are not replicas of real firearms, being miniaturized version of real firearms, mostly made of black or clear plastic.
They have a small bb capacity, usually between 50 and 100 rounds, but they have fair range and a functional hop-up. They have become very popular in recent years, and are now being manufactured by Tokyo Marui. These “minis,” as they are referred to, are not a viable option in games against AEGs since their small ammo capacity, short range and poor far range accuracy leave their wielder at a large disadvantage.  Mini electric guns are able to compete with spring pistols at close ranges however, primarily due to their higher rate of fire.
Automatic electric pistols
Automatic electric pistols, abbreviated AEPs, were first introduced by Tokyo Marui in 2005 with their Glock 18C (followed later by a Beretta 93R model). They were the first handguns to incorporate an electrically powered system that is capable of fully automatic operation.
In cold weather, AEPs are often considered better sidearms than gas powered pistols, because batteries are not as badly affected by frigid weather. Gases like CO2 and green gas are stored in liquid form and require heat in order to vaporize. A gas pistol at 10°F (−12°C) will usually only get one to two usable shots from a full magazine, and even will be at reduced power because of the lowered pressure of the gas.
Because the AEP gearbox and battery are smaller, the velocity of AEP BBs (usually between 200 and 280ft/s (85.3m/s)) is relatively slow by the standards of airsoft simulations, rendering them useful only for close-range simulation. However, the advanced hop up units on these new guns tend to compensate for the low power and can produce an effective range comparable to those of an AEG. CYMA has made a clone Glock 18C, which is a lower priced alternative.
An AEP differs from electric blow-backs because the AEP has a fixed slide (in which there is no external movement of the slide during operation), while an EBB simulates the "blow back" action in the slide experienced in a real pistol or Gas Blow Back (GBB). An AEP, however, has much more power and accuracy.
One of the newer AEP-styled guns is the Marui replica of the Heckler & Koch MP7. It is considerably larger than either of the other guns, and can be upgraded to a much higher power through the use of an external battery, but uses the same system as the AEP, so the classification is ambiguous. It is slightly more powerful than the others and is a suitable choice for CQB (Close Quarter Battle) games due to its small size and decent barrel- to gun-length ratio.
Some semi-automatic pistols can be modified to be automatic pistols. To make them more effective, they use rechargeable batteries supplied with the gun, and can be replaced with a larger battery to make their ROF higher.
Due to restrictions on size, either the electric motor or batteries have to occupy space in the hand grip, reducing the available space for a magazine. Because of this, most AEPs do not use a full size magazine found in most gas powered pistols.
In addition, most AEPs are constructed almost entirely of plastic and have a light, toy-like feeling to them.
Gas-powered
Gas blowback

Gas-powered airsoft guns use the pneumatic potential energy stored within compressed gas to drive the shooting mechanism, and thus operate according to an entirely different design principle to spring- or electrically powered airsoft guns.  The most common type seen is the gas blowback (GBB) guns.  These gas guns use an internal canister (usually within the magazine) that upon trigger-pull releases the prefilled bottled gas via a series of valves to propel the pellet and generate a blowback, which simulates recoil and cyclically loads the next shot.  They are capable of both automatic and semi-automatic operation.
The most common gases[7] used are "green gas" and propane which requires an adaptor. HFC-134a is also commonly used, particularly with pistols which have plastic sliders due to the lower pressure giving a smaller chance of damage to the weaker slide. Less commonly used gases include "red gas" (which is actually HCFC-22), CO2 and nitrogen/high-pressure air. However it is unlawful to use HCFC-22 as a propellant in the US, as it is a Class II ozone-depleting substance and its use as an aerosol propellant has been banned since January 1994 under section 610(d) of Clean Air Act.[8] Red gas is usually avoided unless the airsoft gun has undergone modification, as its relatively high critical pressure can cause damage to the airsoft gun, such as breakage of the slide or bolt. CO2, nitrogen, and high pressure air are less common because they need to be stored at higher pressures than "green gas" or HFC-134a.
The first ever gas powered airsoft guns were commonly referred to as "classic" guns, owing to their age. These guns were most commonly powered by liquid propellants such as R-12 (which was marketed by the Japanese as FLON-12 or DuPont tradename Freon 12) CFC feeding system with a majority of the configurations containing two tanks, one containing the R-12 and one used as an expansion tank, and the gun itself.  R-12 was a commonly used refrigerant for car air conditioning and refrigerators, and is considered a highly potent ozone-depleting substance and listed as a Class I Ozone Depleting Substance by the US EPA.  Its use as a general purpose aerosol propellant has been banned by the US EPA since March 1978 under 43 FR 11301 for use in aerosol use with a very few exceptions.[9]  Its use is also banned in many countries under United Nations treaties.  On Dec 31, 2008, the use of CFCs for medical inhalers were banned.
Later users modified these old guns to be powered by regulated CO2 canisters or nitrogen/high pressure air bottles to increase power and consistency. However, these guns have largely been superseded by the newer and more versatile AEGs, or automatic electric guns. One of the reasons for this is because the most commonly available propellant, R-12, is costly. Additionally, at high flow rates, liquid propellants tend to cool down, eventually freezing. As cooldown progresses, the rate of fire gradually decreases until the gun ceases operation. The user would then be forced to wait for the propellant to warm up again. CO2 is not affected as badly by this tendency, and nitrogen/high pressure air is immune to it. Furthermore, if liquid propellant is introduced into the gun's mechanism, rubber parts can freeze and eventually damage the gun. However, it is unlikely for this to occur since once the gas is released from the containing cylinder it instantly turns back into its gaseous state, and expands rapidly. It is doubtful whether the retained pressure behind the BB before it begins to accelerate down the barrel is enough to keep the gas in a liquid form. Also, any gun that is expected to be exposed to the intense cold of de-pressurizing gas should have materials that can handle it.
Gas power tends to be used in airsoft pistols where size constraints make electric-powered mechanisms impractical. Other instances where gas is favored are where adjustable velocities are required or where a blowback feature is desired. A blowback feature is a mechanism which cycles a slide or bolt to better simulate a real firearm's operation. Because of the mechanical complexities involved with distributing and regulating gas, these guns have largely given way to electric guns for less specialized applications, however, they still remain favorable amongst most airsofters. They are not just limited to pistols; submachine guns, sniper rifles and assault rifles commonly use gas mechanisms. Whilst the submachine gun replicas typically feature a blowback mechanism similar to the pistol replicas, sniper rifle replicas usually omit the blowback mechanism in favor of reduced recoil and increased muzzle velocity.
Along with using gas to power guns, it is also applied for use in replica grenades. These grenades are either projectiles, fired from a grenade launcher such as the M203 or GP-25, or throwable. The shells work on the system of an internal piston, filled with gas. Either a series of BB's or in some cases a rubber or soft foam head is seated in or on top of the shell. When the pressure is released the projectile(s) are shot from the launcher sent downrange.
In the case of the throwable grenades, inside the grenade there is a similar piston to the one used in the shells, but is on a literal "timer" that allows the user to clear the area of effect. BB's or powder act as the projectile in the case of these grenades. Currently both types of grenades are not very common, mostly because grenade launchers are quite expensive and the throwable grenades are not very reliable.
High pressure air systems
High pressure air (HPA) systems are a type of pneumatic airsoft weapon that use externally supplied high pressure air instead of internal gas canisters like the majority of gas-operated airsoft guns.  They work by using a separate high-pressure air tank that is connected to the airsoft gun with a hose, which is connected with a pneumatic motor inside the gun (called an "engine") at where the gearbox would be in a normal electric airsoft gun.  The engine is powered by a fire control unit that can adjust to the desired rates of fire as well as the dwell that determines how much air is released with each individual shot.  There are several types of HPA systems and they vary in both price and performance. Popular HPA brands and engines include PolarStar (Fusion Engine, F1, Jack), Wolverine (Hydra, Bolt, Inferno, Wraith, SMP), Valken (V12), and Tippmann (M4 Carbine)
It is not definitive which style is more effective. It is more up to personal preference.
Hybrid guns
Hybrid airsoft guns are the newest type of airsoft guns on the market.  They are basically standard AEGs or GBB guns with a "little extra reality" built in, and are usually more powerful.
AEG hybrid operation: The magazine is loaded with shell cases, each containing a single plastic pellet.  These shell casings can have a small red cap, the same as those found in any child's toy cap gun placed on the top of them.  These hybrid guns feature an electrically powered, full blowback system and operate on a "round-per-shell" basis such that for every pellet fired, a shell casing is ejected and the cap is fired providing a realistic sound and smoke effect.  Since its debut, the only hybrid guns seen on the market are TOP M4A1, as well as M1 Garand, Kar98, and other rifle models.  These guns are the least common type of gun on the market today and are generally used by collectors and re-enactors rather than skirmishers.
Gas blowback hybrid operation: Hybrid gas blowback airsoft guns are quite similar with hybrid AEGs and their operations are similar with ordinary gas blowback airsoft guns.  A single 6mm pellet is still loaded to a shell casing.  Then it is placed into a magazine.  The airsoft replica itself also has a tank for compressed gas as propellant (such as green gas).  So as the slide/bolt is pulled back, it loads a shell into the chamber.  As the trigger is pulled, it releases a small burst of propellant and the pellet is forced out the barrel.
Training weapons

Airsoft gun manufacturer Systema Engineering (PTW) developed a line of airsoft guns and accessories intended for military and law enforcement training. These airsoft guns are made of aircraft-grade aluminum combined with stainless steel parts that gives strength, stability, weather protection, and easy maintenance.  These training weapons offer a more realistic display of military weapons. Unfortunately they have been plagued by reliability problems and parts availability.  They have also had models banned from the US for being capable of being converted into real firearms.  Two manufactures, King Arms and KWA, came out with ATF-approved gas blowback AR-15 replicas that allowed for correct weapons tear down, manipulation and function that were designed for military use, but were also legal for US citizens to own. The King Arms model required upgrade parts out of the parts to give it reliability, though the KWA was plagued by a weak hop-up system, but otherwise reliable.
Classic guns
Classic airsoft guns are usually the older variety of airsoft guns which are gas-powered though in the recent past other manufacturers have found interest in them. Unlike the gas rifles of today, they can run on either an internal tank using conventional airsoft gas or use an external CO2 or HPA tank much like a paintball gun. These type of guns generally cost considerably more than the standard AEGs. Some models, such as those made by the Sun Project, feature a type of "recoil" provided by these guns.  The rate of fire on these can be regulated by the amount of air being fed through the system, versus using different battery voltages in an AEG. Other manufacturers for example are PolarStar Airsoft and Daytonagun.
Equipment related to the Airsoft gun
Sights
Optical sights are fairly common for use on airsoft rifles; mostly red dot sights[10] for short-range use, and telescopic sights for longer-range use.  These range from inexpensive sights designed for use on pellet guns and .22 rifles, to mid-range sights, usually inexpensive replicas of actual rifle sights (such as replicas of the M68 Aimpoint, Advanced Combat Optical Gunsight (ACOG), and imitation holographic weapon sights that are actually just red dot sights), to actual sights designed for use on rifles, including the EOTech holographic sights, and the Trijicon ACOGs. Replica (or "clone") sights are much cheaper than their real counterparts, but are usually unlicensed, much less durable and reliable, and should not be used with real firearms where violent recoil may damage them or throw the sight off zero. Most optical sights are mounted on a MIL-STD-1913 rail, while other guns, including replicas of Kalashnikovs, MP5s and G36s may have specific proprietary mounts.
Barrel Attachments
There are two main types of barrel attachments for airsoft guns, suppressors and barrel extenders. Suppressors make firing the gun quieter. Suppressors, also called silencers, cannot be expected to work as well as they are depicted on television with real firearms, since airsoft guns are already fairly quiet relative to real weapons. Barrel extenders are used to increase the muzzle velocity of a player's airsoft gun. Having the ability to fire an airsoft gun at a higher muzzle velocity can be the difference between knocking an opposing player out of the game and losing it for your team.[1]
Magazines

Magazines are usually realistic looking replicas of real firearms' magazines and as such are made of the same materials like stamped metal or high impact plastic. They occasionally feature markings and/or engravings that match or mimic their real counterparts.
Airsoft magazines are divided into the following classes according to the number of pellets they hold:
Low capacity (Low-cap):
Low capacity magazines are the type of magazine provided by Tokyo Marui and some other manufacturers with their guns. They are known as "Low capacity" or "low-cap" as they hold drastically fewer BBs than most medium capacity or high capacity magazines. Many contain around 68 BBs (the standard amount for a Tokyo Marui magazine) and are normally loaded by inserting pellets down a shaft, compressing a spring held inside that will later feed the pellets into the gun.
Low capacity magazines offer quiet operation (no rattle or manual winding of high-capacity magazines) and are sometimes the only option available for certain airsoft gun models. They are also useful to help players limit their ammunition consumption and simulate more realism by simulating the 10-30 rounds in a real rifle.
Low-cap magazines almost only come with Tokyo Marui guns whereas some companies like Classic Army or ICS supply high-capacity magazines with their guns. However, most magazines will not feed every single pellet, leaving 2–3 pellets at the end of the magazine or in the feed tube of the hop-up chamber (some players may circumvent this problem by inverting the gun to allow gravity to feed the pellets instead).[11]
Medium capacity (Mid-cap):
These kinds of magazines are either bought or modded to accommodate from 90–190 BB's. Traditionally, they still function like a low-cap/real-cap magazine and as such keep the advantage of quiet operation over high-capacity magazines (that require a winding mechanism), but minimize the disadvantage of a low capacity magazine's lower number of rounds. They are also somewhat more reliable because of the lower level of dry firing due to the higher number of rounds that can be shot off without having to even touch the magazine, whereas high-cap magazines need winding after a few dozen shots. Increasingly, however, winding magazines are being released to the market and can be placed into this category due to their 190 rounds or fewer capacity, though usually when magazines are referred to as mid-cap, it is assumed that they are non-wound magazines.
Mid-cap magazines are somewhat the preferred medium among many players, as they offer a fair number of rounds without winding, bring some variability to game play in terms of magazine change, simulate reality the best and prevent endless spraying from guns that are not really designed to do so. It is not unusual for many games to only allow the use of mid-cap or low-cap magazines in game (with exceptions for weapons intended to deliver a high volume of fire, e.g. light machine guns). Also used by players that play MilSim games, where Mid-Cap magazines are required.
High capacity (High-cap/Hi-cap/Flash Magazines):
High-cap mags hold more shots than a mid-cap (about 200–800), there are three main ways in which they work. The most common type of high cap is one which a wheel has to be wound (often one full wind will load 50-100 rounds). Another type which is most commonly used in support type weapons is the electric magazine, these ones work in a similar way to the wheel magazines. However, the wheel is wound by a small motor within the magazine. The final type of high cap magazine is one which has a string that is pulled in order to turn the wheel. Although these magazines can be wound quickly, the string has been known to snap occasionally and the system not to be as reliable as the other two magazines. The string-wound magazines are known as flash magazines.
Drum/box magazine:
Drum and Box Magazines usually have the greatest ammunition capacity of all airsoft magazines; ranging from 2000 to 5000 rounds. These magazines replicate the ammunition boxes used by belt-fed support weapons such as miniguns, M249s, and M60s. Drum Magazines tend to replicate magazines like the Beta C-Mag and the equivalent for weapons such as G36s, AK-47s and MP5s. Internally these magazines work very similarly to High-Cap magazines and most have a push button operated electric motor to wind the spring that drives the feeding system.
Real capacity (Real-cap):
Real-caps are identical in operation compared to low capacity magazines, but they carry the same amount of ammunition that the real version of the magazine can carry, which is often much less than the low-cap magazine, e.g. an M-16 real-cap will hold 30 rounds instead of the 68 of a low-cap magazine. Few magazines are designed as real-caps; for flexibility it is common to purchase higher-capacity magazines and only load rounds to the equivalent capacity of the real magazine. Some ultra-realistic groups require the magazines to be weighted equivalent to the replicated firearm.[12]
These tend to be used solely by those wanting the most realistic MilSim ("MILitary SIMulation") games. They also offer the stealth of no rattling rounds, but their main use is for the realistic qualities.
Pistol magazines:
There are two general types of pistol magazines: single stack and double stack magazines. Single stack magazines hold anything from 7 to upwards of 20 rounds depending on the weapon type.  The BBs are stacked directly on top of each other, hence the term "single stack".
Unlike the single stack magazines, "double stack" magazines have rounds loaded in a staggered column, similar to many real firearm magazines. This allows for more BBs to be loaded (usually around 30) without extending the length of the magazine. Double stack magazines tend to be wider, requiring a wider grip on some models, like the M1911 pistol. The term "double stack" or "double column" is a common misnomer.
Alternate style magazines:
Some other magazine styles are seen with a few models of airsoft guns, typically airsoft sniper rifles. Most airsoft sniper rifles employ a magazine that is similar to a mid cap magazine as with the twisting spring design seen in most mid cap magazines, while maintaining a relatively low magazine capacity.
Other single shot weapons use "shells" such as shotguns, bolt action sniper rifles, and revolvers. These bullets contain a single pellet, and are ejected by the bolt or the pump action, or manually in a revolver. Some shotgun "shells" contain buck or birdshot, with 12-24+ bb in a single "shell" fired at once.
Performance
Airsoft guns shoot plastic pellets at velocities from 30m/s (98ft/s) for a low-end spring pistol, to 200m/s (660ft/s) for heavily upgraded customized sniper rifles. Most non-upgraded AEGs are in the middle, producing velocities from 90m/s (300ft/s) to 120m/s (390ft/s). The internal components of most guns can be upgraded which can increase the pellet velocity significantly. Using heavier pellets (.25g, .3g, etc.) will significantly reduce the gun's muzzle velocity, but can increase accuracy at range and reduce susceptibility to wind drift. Lighter pellets have less kinetic energy than their heavier pellets, despite their higher exit velocity. Decreasing the pellet's weight does not generally increase its range.  High-velocity AEGs often employ heavier pellets.  Most high-end AEGs, such as Classic Army and Tokyo Marui, should not be loaded with anything lighter than 0.2g pellets, as the lighter pellets (0.12g, 0.15g) are typically made for low-end guns, and are not built to the same quality (such as surface smoothness). The stresses the pellets go under upon firing could shatter lighter or poorly made pellets as they leave the barrel, potentially damaging the weapon.
Airsoft guns can be modified to increase pellet velocity, rate of fire, reliability, or accuracy/range. For an electric airsoft gun, the pellet velocity can be increased by two different methods. The first is upgrading the inner barrel of the gun. The inner barrel is what the BB travels within while in the gun. Stock AEG inner barrels are usually between 6.05-6.10mm. An airsoft inner barrel is considered "tight-bore" when the inner diameter is less than 6.05mm. Typically, tight-bore barrels that are 6.03mm in diameter are installed into stock AEGs, so that accuracy as well as an up to 30fps increase is enjoyed by the player. Tighter bores risk a higher chance of pellet jams and a need for higher quality pellets and require more lubrication as well as a larger cylinder inside the gear-box in some cases(to contain more air to be forced through, most commonly called a "bore-up" upgrade). Tight-bore barrel upgrades as small as 6.01mm are usually reserved for high-powered sniper rifles. The second is simply upgrading the mainspring. Doing this will increase the air pressure subjected to the pellet produced during operation. But due to the higher forces at play, it is advised that other parts should be upgraded together with the mainspring in order to maintain a high level of reliability. The rate of fire is increased by using a battery with a higher voltage, high-speed ratio gears and/or a high-speed motor. Rates of fire can be increased to over 20 rounds per second with very few upgrades, but with careful selection and extreme modification of gearbox components, rates of fire in excess of 50 rounds per second are not unheard of. In the case of gas guns, a higher pellet velocity can be achieved through the use of different types of gases and/or changing the valve. Some gases have detrimental effects to some plastic components inside the airsoft gun.
The ballistics of spring or electric powered airsoft guns differ from real firearms in that a longer barrel will not always result in better accuracy. In spring/electric airsoft weapons, barrel length does not have a significant effect on accuracy. The "sweet spot" for barrel length in a spring/electric powered airsoft gun is around 400-500mm. Past that length, added barrel length will not improve accuracy. In any case, barrel quality, fps consistency, and hopup quality/design are more important factors in regard to accuracy. However, added barrel length will result in slightly increased velocity if the cylinder size and compression are appropriate for the barrel length. For example, a gun with a large cylinder and a long barrel will shoot slightly harder than a gun with a small cylinder and a short barrel(with everything else being equal). This rule will apply even for barrels longer than 500mm, if there is enough cylinder volume and air compression to propel the BB through the barrel. However, the resulting FPS increase will be hardly noticeable. The only considerable advantage of using a longer inner barrel in an AEG or spring powered gun is that it generally will make the gun quieter. Gas powered replicas function more like real firearms. In gas powered guns, added barrel length (to an appropriate degree) will result in significantly increased velocity, and increased accuracy to a degree.
Another common upgrade done by players is in the "hop-up" system, featured in most mid- to high-end AEG's, as well as gas guns and spring sniper rifles.  In this system, the wall of a rubber tube, called a bucking, is forced into the upper path of the pellet right before it begins flying down the inner barrel.  This contact imparts backspin, which in turn gives the pellet a Magnus lift to maintain a flatter trajectory for a longer period of time.  This is adjusted by screws or gears that cause the bucking to only show a small or large presence in the barrel.  Different degrees of firmness of the rubber are considered when a hop-up is being upgraded.  The hop-up can either make or break an airsoft gun's range and accuracy: too much hop-up makes the pellet fly very straight, but can also cause it take a sharp curve upward toward the end of its flight. If a light enough BB is used, adjusting the hop-up can even cause the trajectory to curve upwards straight out of the barrel.  The hop-up is adjusted around the weight of the pellet and the speed at which it is leaving the barrel.  A well-tuned hop-up puts just enough spin on the pellet to maximize its range without drastically effecting the curvature of its trajectory.
Airsoft guns commonly come with mounts or rails on which the airsofter can add external accessories. Some common customizations added are flashlights, scopes and lasers. Many airsoft guns are made 1:1 in scale and detailing to their real steel counterparts, but few are able to safely swap external components. Airsoft replicas of real scopes are commonly made available for sale at a much lower price (sometimes thousands of dollars less). The replicas differ from their real-steel counterparts in that the replicas are not made to function in a high-recoil environment such as that in of an actual firearm. In no way can an airsoft rifle be modified to shoot real ammunition. In most cases, add-ons are more for aesthetics than performance. However, scopes can allow for greater precision at longer ranges with proper firing technique by the user/operator (the installation of a scope does not physically make the gun fire pellets more accurately).  Other attachments, such as replica grenade launchers can act as under-barrel shotguns, and a mock silencer can be added to provide concealment for a longer inner barrel therefore improving accuracy and range.
Safety concerns

Airsoft is safe when played with proper protective gear.  Most airsoft guns on the market are usually below 350ft/s (110m/s), but projectiles expelled from any type of airsoft gun can travel as slow as 65ft/s (20m/s) to more than 700ft/s (210m/s) and are capable of breaking skin at 300ft/s (91m/s). For example, skirmish play in the United Kingdom has a maximum of 350ft/s, with some airsoft locations having a limit as low as 290ft/s.[13] If under 300ft/s (91m/s), the hit would have to be within a short range. Blood can be drawn, but injuries that do occur are predominantly superficial. Full-seal protective eyewear (goggles or glasses) is widely considered the minimum protection for airsoft players, as the eyes may be injured by any type of impact. The least amount of protection a player should seek will meet or exceed ANSI/ISEA Z87.1 standards, which indicates the eyewear is rated for ballistic strikes. Mesh eyewear has also seen some limited use by players due to low cost and its inability to fog, although it has drawn some criticism for its non-impact rated construction and vulnerability to debris. Some impacts (particularly at close range with powerful guns) are capable of cracking or damaging teeth. Dentists have reported broken teeth that require root canal and crowns to repair damage. A face mask (like that used for paintball) is recommended to protect eyes and teeth. Metallic mesh masks and mouth guards have recently seen popular use.
There are legal issues in airsoft as well as several rules imposed in a game by game basis. Most indoor airsoft fields only allow up to 350ft/s (110m/s), and most outdoor fields begin capping near the 410ft/s (125m/s) for rifles and 525ft/s (160m/s) for long-range guns such as sniper rifles. Most outdoor fields also impose a minimum engagement distance for guns firing over a certain range, normally for squad support weapons and sniper rifles. In order for an airsoft gun to cause any serious injury, it would have to be well over these limits and in close proximity. To even reach such speeds, the gun would have to be highly modified. So it is therefore unlikely to cause permanent or serious damage with any stock airsoft gun. The use of metallic BBs, or any foreign objects, is very dangerous for the user and other people and property in close vicinity, and may damage the airsoft gun as well. However, specially designed and built metallic 6mm BBs for airsoft guns can be found on the market. These metallic BBs should not be used for airsoft play because they can break through goggles and other safety gear.
Although airsoft guns in the United States are generally sold with a 6mm (0.24in.) or longer orange tip on the barrel in order to distinguish them from real firearms, this is not in fact required by federal law. There is some controversy on this topic as Title 15 of the Code of Federal Regulations, on foreign commerce and trade, stipulates that "no person shall manufacture, enter into commerce, ship, transport, or receive any toy, look-alike, or imitation firearm" without approved markings; these may include an orange tip, orange barrel plug, brightly colored exterior of the whole toy, or transparent construction (part 272.2, formerly part 1150.2). However, section 272.1 (formerly 1150.1) clearly indicates that these restrictions shall not apply to "traditional b-b, paint-ball, or pellet-firing air guns that expel a projectile through the force of compressed air, compressed gas or mechanical spring action, or any combination thereof." [14] Local laws may differ by jurisdiction. Full or partial preventive painting of airsoft guns as a legal obligation to avoid confusion of the airsoft replicas with real lethal weapons is in practice in several jurisdictions around the world.
A common controversy referred to as "Pumping"  or "Roping" is the act of purposely cheating and/or firing 20+ airsoft rounds at one player until they run away or submit in pain. Popular videos such as "Rip Kid" [15] and "SC Trip 2015"[16] have both documented the act of "pumping". Many are concerned over the safety of the player(s) on the other end, as well as their probability of returning to the hobby. Several Airsoft Arenas/Fields across the US have implemented strict "Semi Auto Fire Only" rules, as well as other rules aimed at deterring players who come out and intend to harm other players.

Police shootings
On January 13, 2006, Christopher Penley, a 15-year-old student with an airsoft gun painted entirely black, was killed by a SWAT team member at Milwee Middle School in Longwood, Florida.
On October 22, 2013, 13-year-old Andy Lopez was shot by a Sonoma County sheriff's deputy Erick Gelhaus. Lopez was walking with other children and carrying an airsoft gun that was designed to resemble an AK-47 assault rifle. Gelhaus opened fire, killing Lopez with seven bullets.[17]
On August 5, 2014, John Crawford, while handling a BB gun in a Walmart store near Dayton, Ohio, was shot to death by Beavercreek Police.
On November 22, 2014 in Cleveland, Ohio, Tamir Rice, a 12-year-old boy with an airsoft gun, was shot and killed by police.  After a 911 caller reported a juvenile male with a "probably fake" gun on a playground, police arrived on the scene, but had not been told by the dispatcher that the gun may have been fake.  Police reported that they asked the boy to show his hands, but he reached for his waistband instead.  The police fatally shot him within two seconds of arriving on the scene.  Police later said that the orange tip indicating the gun was a toy had been removed.[18][19]
On November 25, 2014, police in Vancouver, Washington reported to the scene of a domestic dispute to find 31-year-old Sebastian T. Lewandowski with an airsoft replica of an AR-15. When he refused to put it down, officers shot and killed him.
Trademark problems
Some airsoft guns can be such accurate replicas that they violate intellectual property laws (specifically those regarding trademarks), most notably some models from Tokyo Marui bearing Colt or Heckler & Koch trademarks that may not be imported into the United States. Certain companies such as Classic Army or ICS avoid this problem by licensing their replicas from the original manufacturers such as ArmaLite by license from ActionSportGames or Olympic Arms. The airsoft company ActionSportGames has licensed trademark rights from many well-known firearm manufacturers, such as Armalite, Dan Wesson, CZ, Steyr, STI, B&T, Franchi etc.. Another company who licence the designs of gun companies is Evolution International. They have a portfolio of exclusive licences from ADC Armi Dallera Custom, TangoDown, Z-M Weapons, DSR precision, Lone Star Tactical, and SAR.
In addition, there have been reports of companies taking action in defense of their intellectual property rights. Some end users have made attempts to sell their guns, some in the style of Glock pistols, only to find Glock blocking the sale and threatening legal action.
In addition to these actions, Glock, as well as HK, have blocked the sale, trade and distribution of replicas bearing resemblance to their products.[20][21][22]
See also
Airsoft pellets
Legal issues in airsoft
Air gun
BB gun
Paintball
Entertech
Xploderz
Nerf, a similar gun that's closely and safely related to Airsoft.