Airsoft guns are replica toy guns used in airsoft sports. They are a special type of low-power smoothbore air guns designed to shoot non-metallic spherical projectiles (pb) often colloquially (but 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 airguns, 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 a battery-powered electric motor gearbox (e.g. AEGs); and pneumatic, which operates by valve-controlled release of prefilled bottled gas such as compressed propane mixed with silicone oil (commonly known as “Green Gas”) or CO2 canisters (e.g. GBB guns), more often mistakenly described as rifles.

Airsoft guns are often designed to realistically resemble actual guns, making it difficult to distinguish them despite the orange muzzle tips in some jurisdictions. This has led to police shooting airsoft gun handlers believing these are real firearms and a deadly threat.

Airsoft Gun Types

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 and underpowered) in design to spring-piston air guns and have the same operating 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 400–700 ft/s (120–210 m/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 long 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 extremely low temperatures. This represents one of the major advantages of spring airsoft gun, as it can be fired in practically any situation 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.

There are various methods of manufacturing Spring-powered guns, and the representative assembly methods are real gun assembly and left/right junction. The left/right junction is the first assembly method among Spring-powered guns. The advantage is that it is easy to assemble. However, due to various parts such as screws, there is a disadvantage that external details are inferior. In the case of most revolvers and rifles with left/right junctions, this method is worn on the head due to structural cost issues. The real gun assembly method refers to reproducing and assembling parts such as the body of a real gun as it is. Spring-powered guns using this method are estimated to have appeared in the 1990s, and the countries that made them are estimated to be South Korea (Spring-powered pistol) and Japan (Spring-powered sniper rifle). The advantage is that details can be saved and durability is better than left/right junction. The downside is that it takes time to make molds for parts such as the outer body. Currently, most Spring-powered guns using this method are pistols and sniper rifles. In particular, pistols can be easily manufactured in terms of structure and it is not expensive to make the outer appearance of the body, so a lot of products adopting this method are increasing.

Battery-powered

Automatic Electric Guns (AEG)

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 the pellets via the compression of air and 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. These guns often attain muzzle velocities from 150 to 650 ft/s (46 to 198 m/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 8.4 V large battery pack, with a capacity between 2200 and 5000 mAh. Also available are “mini” and “stick” batteries, which generally have 900 ~ 1600 mAh capacities. Voltages for NiMH batteries range from 7.2 V to 12 V. 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. 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 7.4 V or 11.1 V, and varying between 500 mAh and 6500 mAh.

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.

airsoft Guns are like potato chips.  you can’t just have one.

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).

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.

Gas-powered

Gas Blowback (GBB)

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 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. 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. Its use is also banned in many countries under United Nations treaties. On December 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 (HPA)

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.