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About Airsoft Weapons
Airsoft guns are the primary weapon systems players use when playing airsoft. They are one of the most important pieces of equipment airsoft players use and airsoft games are usually won or lost depending on the types of airsoft guns in the game and players' accuracy with those weapons.
These airsoft weapons and their airsoft accessories are some of the first few things people think about when it comes to airsoft. Because of this, airsoft players think and talk about their airsoft guns and how they want or plan to modify and upgrade them the most. This is also the part of airsoft that costs most, and therefore, it's essential to make a good choice selecting a good quality airsoft gun brand and making the choice to buy an airsoft gun type that the player will be satisfied with.
Choosing the airsoft gun that is right for you all depends on knowing the strengths and weaknesses of the airsoft gun, the airsoft gun's capabilities, and the play styles associated with different types of airsoft guns. If you are looking for information about airsoft guns and which type you need to play airsoft, you've come to the right place.
We will start with the basics and talk all about of airsoft guns including the different types of guns, the hardware inside of the airsoft guns, what powers the guns and allows them to shoot airsoft BBs, what magazine types are good to use with your airsoft gun, and other things like choosing batteries for electric airsoft guns and gas for blowback guns.
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Basic Information About Airsoft Guns
Airsoft guns shoot plastic 6mm (six millimeter) airsoft BBs out of their barrels. This is the "ammo" used in the airsoft guns and the BBs are usually stored in the airsoft gun magazines. The guns shoot these BBs using several methods. Some airsoft guns use air to fire the BBs and propel them out of the gun barrel. Other guns use gas mixtures to fire the BBs. However the airsoft gun fires the 6mm airsoft BBs, the science and inner workings of the airsoft guns remain roughly the same.

Airsoft Gun Inner Workings and Hardware
The science behind the hardware and inner workings of airsoft guns works like this, the BBs are propelled through the airsoft gun barrel by differences in pressure. High pressure air or gas is sent from behind the plastic airsoft BB which moves the BB down the gun barrel where the pressure is lower. The pressure "pushes" the BB.
The chamber of the airsoft gun creates the high air pressure difference using hardware like springs, gears, pistons, values, motors, cylinders, cylinder heads, seals, and nozzles. This includes mechanisms and small tension springs inside the pressurized, loaded piston in the airsoft gun cylinder. The metal hardware components are usually made of hardened steel. When the airsoft gun magazine loads and chambers an airsoft BB, the airsoft gun piston is drawn back and the airsoft gun spring is loaded under tension.
At this point, the airsoft gun piston locks in place at the rear position on the piston teeth and a 6mm plastic airsoft BB is loaded from the airsoft gun magazine and fed into the gun barrel using the loading ramp in the chamber. The piston has a cylinder head which is sealed around the edges with a rubber gasket which creates a sealed tube. When the airsoft player pulls the airsoft gun trigger, the trigger releases the piston which moves forward as it is pushed by the airsoft gun spring creating high pressured air in front of the piston since the air can only move forward towards the airsoft gun barrel.
As the spring decompresses, the piston moves quickly forward which rapidly compresses the air in front of the cylinder head. This movement creates the high pressured air needed to continue down the gun barrel propelling the airsoft BB out of the airsoft gun. In fully automatic airsoft guns like AEGs and green gas blowback (GBB) airsoft guns, this compression and expansion can take place hundreds of times a minute and many airsoft BBs are fired in very fast succession.
In electric airsoft guns like automatic electric airsoft guns (AEGs), many of these airsoft gun parts and hardware described above are located inside the internal gearbox in the receiver of the airsoft gun. The gearbox contains a balanced combination of these parts which move in sequence to rapidly create compression over and over as the airsoft weapon is fired. Experienced airsoft gun technicians and curious hobbyists can also use specific airsoft gun tools to modify, upgrade and improve the AEG gearbox hardware, efficiency, and functionality.


BBs Used In Airsoft Guns
About Airsoft BBs
Airsoft guns fire round balls of spherical plastic. These balls are called "airsoft BBs". They are 6mm in diameter and come in many different BB colors, weights, and sizes. The weight of airsoft BBs are measured in grams. Some of the standard weights of airsoft BBs include (from lightest to heaviest): 0.12g, 0.20g, 0.25g, 0.28g, 0.30g, 0.36g, 0.43g, and 0.46g. The weight of the airsoft BBs depends on the use case airsoft players need for and the airsoft guns they are using.
Lighter airsoft BBs like 0.12g are usually only used in small airsoft pistols. Standard airsoft BBs like 0.20g and 0.25g are commonly used in any airsoft gun in standard playing conditions. Heavier airsoft BBs like 0.36g and 0.43g are used in airsoft sniper rifles for greater accuracy at longer distance or with airsoft rifles in windy conditions where BB flight stability is needed.
Keep in mind that wind affects airsoft BBs based on the BB gram weight. Kinetic energy is also a factor to consider as the airsoft BB leaves the muzzle of the airsoft gun barrel. Lighter weight BBs lose their kinetic energy faster due to air resistance than heavier weight BBs. When dealing with and calculating the kinetic energy of an airsoft BB, airsoft players also need to keep the FPS of the airsoft gun in mind.
Standard Airsoft BB Weights for FPS Chronos
When determining the feet per second (FPS) shooting speed of an airsoft gun, 0.20g 6mm airsoft BBs are the standard size and weight used to set the FPS baseline. The 0.20g airsoft BBs are fired out of the airsoft gun being tested and through a chronograph instrument to measure velocity, Joules or energy, and other airsoft gun firing metrics. Oftentimes, the airsoft guns will be shot several times with the average or highest FPS reading used for the gun's FPS reading.
This standard FPS testing measure with 0.20g airsoft BBs is used to check FPS readings at airsoft events and playing fields. These readings can range from acceptable to "hot" depending on how fast the airsoft gun shoots. A "hot airsoft gun" means the gun is shooting faster than the established FPS standards and over the limits for the specific type of airsoft gun. Airsoft fields take these FPS measurements and readings into account when determining things like airsoft field FPS regulations.
Airsoft guns which do not chrono well and are classified as "hot" airsoft guns may not be allowed in gameplay at certain airsoft fields. The airsoft guns which successfully pass the FPS tests are usually marked at the chrono station by a small colored zip tie which is located somewhere around the front of the airsoft gun. This should not be removed for the duration of gameplay or the airsoft event.
Post Chrono Airsoft Gun Mods at Airsoft Fields and Events
It is up to the airsoft player's honor to not modify, swap AEG springs, or upgrade other airsoft gun components which affect FPS after being chronoed. If upgrades or AEG spring swaps do need to be made, airsoft players need to let game staff know and rechrono their airsoft gun using 0.20g airsoft BBs again. Be careful making any modifications past "hot" limits after chronoing! If airsoft players mod their guns and players question their FPS limits, game staff can make players rechrono their guns at any time. Cheating by upgrading your airsoft gun post chrono can lead to removals from airsoft events and bans from airsoft fields.

Airsoft Gun FPS and Airsoft BB Weight
We can determine the optimal airsoft BB weight to use in an airsoft gun using the following values for kinetic energy and airsoft BB weight by gram. These values are recommended by Novritsch airsoft BBs for getting the most range and performance out of airsoft sniper rifles. You can learn more about Novritsch airsoft BBs here.
- 0.25g weighted airsoft BBs in airsoft guns with 230 to 330 FPS or 0.5 to 1.0 Joules
- 0.28g weighted airsoft BBs in airsoft guns with 330 to 400 FPS or 1.0 to 1.5 Joules
- 0.30g weighted airsoft BBs in airsoft guns with 360 to 400 FPS or 1.2 to 15 Joules
- 0.32g weighted airsoft BBs in airsoft guns with 360 to 400 FPS or 1.2 to 1.5 Joules
- 0.36g weighted airsoft BBs in airsoft guns with 400 to 470 FPS or 1.5 to 20 Joules
- 0.40g weighted airsoft BBs in airsoft guns with 430 to 520 FPS or 1.7 to 2.5 Joules
- 0.43g weighted airsoft BBs in airsoft guns with 450 to 520 FPS or 1.9 to 2.5 Joules
- 0.46g weighted airsoft BBs in airsoft guns with 490 to 700 FPS or 2.2 to 4.5 Joules
- 0.49g weighted airsoft BBs in airsoft guns with 520 to 700 FPS or 2.5 to 4.5 Joules
These weight to FPS energy ratios give us a usable range for optimum performance in sniper rifle airsoft guns. For standard airsoft guns like AEGs, airsoft BB weight still matters. We can use a simple chart like the one below to see which airsoft BBs will work optimally with the FPS of the airsoft gun.
If you are playing at an airsoft field, be sure to check the field guidelines around acceptable FPS for your airsoft gun type and style. Ask game staff about any questions you have. Most airsoft fields, airsoft arenas, and designated playing areas have FPS limits. You will have to "chrono" your airsoft gun's FPS using a chronograph instrument which calculates the airsoft BB speed to ensure you are within the required limits to use the airsoft gun on the field during game play.

Calculating Airsoft Gun Muzzle Velocity and Kinetic Energy
If you are interested in calculating the muzzle velocity and kinetic energy of your airsoft gun, we can dig into the world of physics and potential energy to use the formula for kinetic energy. The kinetic energy formula is seen below. We won't get too into the weeds here because we are mainly talking about airsoft guns here. The formulas are provided for knowledge and reference however.
Kinetic Energy Physics Formula
Ek = 1/2mv2
This is the standard written notation for the kinetic energy physics formula we will need to calculate the energy behind a fired airsoft BB.
Kinetic Energy Physics Formula
Scientific Notation

This is the scientific notation representation for the same kinetic energy physics formula. Seeing the formula in this format gives us a better idea about what the operators do.
Both of these formulas for kinetic energy are the same. The we can see the same values are passed where:
- Ek is kinetic energy
- m is the mass in kilograms of the airsoft BB
- v is the velocity in meters per second
- The velocity is squared
- The mass times velocity squared is divided by one half
Kinetic Energy To Joules for Airsoft Guns
So, since we know the kinetic energy formula from above and the fact that kinetic energy (Ek) is directly proportional to the mass of the object and to the square of its velocity (Ek = 1/2mv2), we can use this information to calculate the related Joules (J) of energy.
We will need to convert grams to kilograms for the Joules energy calculation. The weight of an airsoft BB comes in handy here since for example, a 0.25g airsoft BB is 0.00025kg in weight (1,000 grams = 1 kilogram). If the mass of an airsoft BB has units of kilograms (add two zeros to the airsoft BB weight since the BB weight is grams) and the velocity of meters per second (using chronograph speeds), the kinetic energy of an airsoft gun has units of kilograms-meters squared per second squared.
Therefore, the kinetic energy of airsoft guns is usually measured in units of Joules (J) where one Joule of energy is equal to 1kgm2/s2.
Why We Should Care About Joules and Airsoft Guns
That's all fine and great you might say, but why should we care about all this science, energy, and math? Well, if you really want to get into modding airsoft guns, know these calculations are important to understand and limit how high the airsoft gun's muzzle velocity can be to still be legal and usable on airsoft fields. It goes back to airsoft field limits FPS (which is part of the energy calculation of the airsoft gun).
If you know the FPS limit, you can dial the energy of your airsoft gun right up against it by customizing your gun for maximum performance, range, and FPS. For example, if the standard for airsoft guns is to have a maximum of 0.8 Joules of energy, this equals roughly 90 MPS (meters per second - m/s) which is about 295 FPS with a 0.20g bullet. This is a really low FPS example and most fields are much higher (around 400 FPS), but the example shows you can compare Joules to FPS.
About Airsoft Gun Joule Creep
Now that we understand kinetic energy and Joules, we can talk about "Joule creep". This is a phenomenon where an airsoft gun shoots lighter 0.20g airsoft BBs at around 1 Joule but also shoots heavier airsoft BBs like 0.30g+ BB weights at higher Joule energy levels over 1 Joule.
This occurs because of the volume of the air behind the airsoft BB which pushes it out of the airsoft gun barrel when the BB is fired. A lighter weight airsoft BB like 0.20g needs less air to move it completely out of the gun barrel. A heavier weight airsoft BB like 0.30g weighs more, so it needs more air to spend more time trying to push it out of the barrel. This added time spent building up air volumes behind heavier BBs allow them to generate more kinetic energy inside the airsoft gun barrel and have a high Joule energy leaving the muzzle of the gun.
Airsoft Guns Capable of Joule Creep
Airsoft guns which are capable of Joule creep have to have extra amounts of air or gas in the chamber. Because of this fact the following types of airsoft guns are susceptible to the Joule creep phenomenon:
- Gas blowback (GBB) airsoft guns - The added gas from the blowback mechanism increases the volume of gas available in the gun's chamber and consequently the amount of gas propelling the airsoft BB out of the airsoft gun barrel.
- Electric airsoft gun AEGs with over volumed cylinders - Using certain cylinders in AEG gearboxes like type 0 cylinders which do not feature ports allows more air into the cylinder. When the piston compresses, the extra air volume is forced out of the barrel, shooting the airsoft BB and creating Joule creep.
- Polarstar and HPA airsoft guns - These airsoft guns use systems of "Fusion engines", cylinders, hoses, regulators, and compressed high pressured air (HPA) tanks to fire the airsoft BBs out of the gun barrels. This type of airsoft gun action can easily create Joule creep as the high pressured air flowing into the Fusion engine allows the gun to fire continuously and is regulated by the gun operator.
Specific Example of Joule Creep
Like we talked about earlier, an airsoft gun with excessive air volume shooting a lighter weight 0.20g airsoft BB has extra air volume which is not required to shoot the BB out of the gun barrel at 1 Joule of energy. This changes when a 0.30g airsoft BB is used since the extra air has more time to build up behind the heavier weight of the airsoft BB to help it gain more kinetic energy as it leaves the gun barrel. Check out the graphic below for a visual idea of what Joule creep looks like.

Why We Should Care About Increased Joules
A lot of airsoft players care about FPS. FPS is cool right? It defines how fast you are shooting airsoft BBs, but the Joules and energy behind the airsoft BB also matters. That is why we should care about Joule creep. Heavier airsoft BBs can travel farther with more energy when fired at the same FPS as lighter BBs.
- If a 0.20g airsoft BB at 1 Joule shooting around 300 FPS can accurately engage targets at around 120 to 150 feet
- Then a 0.30g airsoft BB at 1.3 Joules shooting around 300 FPS will have a longer range since it weighs more and may be able to accurately engage targets at around 150 to 170 feet
This matters a lot when playing airsoft. It is frustrating and kind of unfair game play if you are getting tagged by airsoft BBs at ranges where you gun can't even reach the other player. The bottom line is that you need to understand what Joule creep is and understand how Joule creep works. Try not to abuse Joule creep on the airsoft field. Airsoft is about having fun, playing with friends, and building your tactical skills. Not sitting back and taking unfair advantages of long ranged distance shots while abusing Joule creep.
Airsoft Gun FPS Limits and Laws
If you have specific questions about the legality of FPS and Joule limits in your state or country, consult your local laws. Different states, countries, and areas have different laws around airsoft guns. A good way to check airsoft laws and guidelines near you is to call a local airsoft shop, airsoft playing field, or check around on the internet.
For example in Sweden, airsoft guns can be used there with extremely FPS ratios. M220 airsoft gun springs capable of 750 FPS are known to be legal in certain places. Semi-automatic and fully-automatic airsoft guns can be around 3 Joules. However, bolt action rifles and other manually cocked airsoft guns can range as high as 10 Joules. These Joule ratings are measured about 4 meters from the airsoft gun barrels. Because of these high limits, Sweden is known to have one of the highest FPS limits on airsoft guns in the entire world.
When thinking about airsoft guns and FPS, consider that the standard airsoft gun with an energy level of 0.8 Joules has an effective, accurate range of about 30m or 100 feet. Accuracy is a relative term of course. Keep your engagement distance in mind when shooting at other players with high FPS airsoft guns. Also, keep CQB rules in mind since some fields do not allow you to shoot players with primary airsoft guns like AEGs and sniper rifles from less than 15 feet away. It is best to transition to a sidearm like an airsoft pistol at these close distances.
Airsoft Guns: Types and Styles
Types of Airsoft Guns
Airsoft guns are usually divided into different types based on how they are powered and which type of mechanism shoots the airsoft BBs out of the gun. There are three main types of airsoft guns which are usually found in most airsoft games:
- Spring airsoft guns
- Electric airsoft guns (including AEGs and HPAs)
- Gas airsoft guns (including green gas and CO2 non blowback, partial blowback, and fully blowback)
Each type of airsoft gun has pros and cons which make it better or worse for individual airsoft players depending how they like to play or their airsoft team role like sniper, grenadier, or squad machine gunner.
Learn More About How They Work
Do you know how the three types of airsoft guns work? Check it out!
Styles of Airsoft Guns
Most people refer to things that shoot airsoft BBs as "airsoft guns", but that is a giant catch all category. There are several different styles of airsoft guns including pistols, sub-machine guns, AEG assault rifles, short barreled rifles, designated marksman (DMR) rifles, sniper rifles, squad weapons (like M60/M240 Bravo airsoft machine guns), and other special weapon types. Some people also group airsoft sub-machine guns and machine guns into the rifle group. We will cover some of those topics in detail below, but we just wanted to clarify what falls under airsoft guns.
The types of airsoft guns above (how they shoot BBs) shouldn't be confused with the styles of airsoft guns like:
- Pistols
- Sub-machine guns
- Assault rifles
- Squad support machine guns
- Sniper rifles
Keep in mind a style of gun like an airsoft M4 assault rifle can have multiple types of the same style like a spring powered airsoft M4, an AEG powered airsoft M4, and a gas or CO2 powered airsoft M4. These airsoft guns look the same (they all look like an M4 rifle), but they are different since they shoot the airsoft BBs out of the rifle with spring, electric, or gas mechanisms. We will talk more about these later down below along with the specific types of each style of airsoft gun.
Visual Guide To Airsoft Gun Styles





Learn About Airsoft Pistol Styles
There are several types of airsoft pistols including CO2, green gas, spring powered, and AEG automatic electric pistols.
All About Airsoft Gun FAQs
Find answers to your gun questions.
Airsoft guns are the primary weapon systems players use when playing airsoft. The main types include rifles, sniper rifles, pistols, SMGs, and shotguns.
Airsoft guns shoot 6mm plastic BBs known as airsoft BBs.
The most common airsoft BB weight is 0.20g.
The standard 0.20g weight airsoft BB is the most common BB used for chronoing airsoft gun FPS at airsoft fields.
The kinetic energy of an airsoft BB increases with BB weights and FPS.
The muzzle velocity of an airsoft gun involves kinetic energy and uses a physics formula of Ek = 1/2mv2. Ek is kinetic energy. m is the mass in kilograms of the airsoft BB. v is the velocity in meters per second. The velocity is squared. The mass times velocity squared is divided by one half.
The kinetic energy of airsoft guns is usually measured in units of Joules (J) where one Joule of energy is equal to 1kgm2/s2.
Joule creep is a phenomenon where an airsoft gun shoots lighter 0.20g airsoft BBs at around 1 Joule but also shoots heavier airsoft BBs like 0.30g+ BB weights at higher Joule energy levels over 1 Joule.2.
Airsoft guns which are capable of Joule creep have to have extra amounts of air or gas in the chamber. Because of this fact the following types of airsoft guns are susceptible to the Joule creep phenomenon. Gas blowback (GBB) airsoft guns. Electric airsoft gun AEGs with over volumed cylinders. Polarstar and HPA airsoft guns.
Gas blowback airsoft guns can have Joule creep when the added gas from the GBB blowback mechanism increases the volume of gas available in the airsoft gun's chamber. Consequently, the amount of gas propelling the airsoft BB out of the airsoft gun barrel is increased. The result is a higher energy level over 1 Joule when shooting heavier BBs.
Electric airsoft gun AEGs can have Joule creep with over volumed cylinders. Using certain cylinders in AEG gearboxes like type 0 cylinders which do not feature ports allows more air into the cylinder. When the piston compresses, the extra air volume is forced out of the barrel, shooting the airsoft BB and creating Joule creep with heavier airsoft BBs.
Polarstar and HPA airsoft guns use systems of "Fusion engines", cylinders, hoses, regulators, and compressed high pressured air (HPA) tanks to fire the airsoft BBs out of the gun barrels. This type of airsoft gun action can easily create Joule creep as the high pressured air flowing into the Fusion engine allows the gun to fire continuously and is regulated by the gun operator. The heavier BBs are fired with more energy if used improperly.
Joule creep increases the range of airsoft guns creating unfair game play. A 0.20g airsoft BB at 1 Joule shooting around 300 FPS can normally accurately engage targets at around 120 to 150 feet. With Joule creep, a 0.30g airsoft BB at 1.3 Joules shooting around 300 FPS will have a longer range since it weighs more and may be able to accurately engage targets at around 150 to 170 feet.
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