Rules of the Game Part II

Electric motors generations:
• EG560 1st Generation Tokyo Marui Motor. No longer used, except for a specially tuned version in the FAMAS.
• EG700 2nd Generation Tokyo Marui Motor. Standard in most guns
• EG1000 3rd Generation Tokyo Marui Motor. Higher speed motor than the EG700 motor, but with slightly less torque. Widely accepted as the best stock motor.

Airsoft Gun parts and upgrades

After a while most players begin to think about upgrades and to improve their weapon. The first thought is probably to increase the pellet velocity to gain extra range. But the only weapons that need longer ranges are rifles such as sniper rifles and the real normal intention is to increase the durability and lifespan of the weapon. Most players settle for merely increasing the battery size and spring strength.

When an airsoft weapon is upgraded to increase pellet velocity, the weapons lifespan will decrease. The power of an airsoft weapon depends on three things: the strength of the spring that pushes the piston forward, the amount of air the piston compresses and the precision of the barrel. When a weapon is highly upgraded it becomes a specialised tool for serious airsoft skirmish and to dryfire (i.e. without pellets) puts an increased strain on the parts.

Always remember that upgrades can invalidate warranty.

Spring:
There are two ways to measure how strong a spring is compared to a standard spring. The Percentage system and the Meter Per Second system. A standard AEG has a pellet velocity of 90 m/s (100%) with a 0.20 g pellet. A M100 spring increases this velocity to 100 m/s. There are M100, M120, M130, M140, M150 and M160 springs. The percentage system is harder to use since it doesn't easily tell what the weapon will perform like. A very powerful spring requires that the entire gearbox is replaced.

Bearings & bushings:
The axles inside the gearbox are attached to the housing by small plastic bearings and these will eventually wear down. If these bearings are exchanged to metal bushings or even ball bearings, the lifespan of the mechbox will increase (almost double according to many players). Ball bearings allow higher rates of fire as well. Shims are thin metal washers added to the axles that make sure that the gears in the gearbox are precisely aligned.

Barrel:
A standard airsoft barrel often has an internal diameter of 6.12 mm. If this barrel is exchanged for a precision barrel with a 6.04 mm internal diameter the amount of air that slips by the pellet reduces and the benefits is that the pellet has less spread and about 5% to 10% extra velocity, depending on the barrel length. The downside is that the barrel clogs up more often when low quality pellets are used and has to be cleaned more often. A longer barrel increases range, but the barrel can't be too long since if the amount of air in the barrel is more than the amount of air the piston push forward, a vacuum will develop in the barrel and the pellet will be sucked back with a big speed reduction. There is a method called 'cratercutting' that has the effect that just before the pellet leaves the barrel the air slips by and cuts a hole in the wall of air that is formed in front of the barrel. This technique is normally used by players aiming to increase the range of the weapon.

Battery:
If a battery's voltage increases, so do the rounds per minute in an AEG motor. All standard AEG batteries are 8.4 volts and the only difference between the different sizes is that a large battery has a capacity of 1300 mAh, while the other small standard batteries have capacity of 600 mAh. This means that a large battery will last for about twice the amount of shots. Upgrades inside a gearbox often reduce the rate of fire and if you then use a battery with a higher voltage like 9.6 V or 10.8 V the rate of fire wont drop as much or even increase. A higher voltage also wears a motor down faster and more maintenance is required. It is possible to use 12 V to power an AEG but this isn't to recommend since the wear is increase very much, the contacts in the trigger is faster worn out and the overall lifespan is sharply reduced.

A battery with a higher capacity (more mAh), will last longer on the field. An upgraded weapon also requires more current and the amount of shots that can be fired will decrease unless a bigger battery (more charge) is used. The usual battery is NiCd (nickel cadmium), but there is another type called NiMH (nickel metal hydride). The NiMH usually has a higher capacity (mAh), but usually offer less current and can't drive the larger springs (i.e. M120). However if you do your research you will find 'high drain' NiMH batteries available as well. A 20 ampere or higher 'drain' is ample for most upgrades on an AEG, and 30 A will drive even the highest powered springs (M130+)

Gears:
The normal gears in a gearbox have an approximate lifespan of 30,000 shots, and a new set of gears will last longer since they are made from a material of greater strength. There are sets that increase the rate of fire but reduce the motor's power and there are also sets that reduce the rate of fire but increase the motor's power. The 'Helical Cut Gears' are a special set that grip better between the gears and don't break as easily as standard gears. The largest supplier of upgrade and replacement parts is Systema.

Nozzle:
A small plastic or metal nozzle seals the space between the air-piston and the BB pellet. This nozzle helps to maximize the air-flow fed from the cylinder to the barrel; therefore, reducing wasted air pressure and resulting in a slightly increased pellet velocity.

Motor:
Most upgrades reduce the rate of fire. By switching to a stronger motor the rate of fire isn't reduced as much. An upgraded AEG should have at least an EG700 motor. The strongest motor is EG1000. All new models that Tokyo Marui releases have EG1000 motors, but many of the older models have EG700 or even EG560. Not all AEG's can have a motor upgrade. If the original spring isn't replaced with one stronger than M120, the EG560 motor can take it. However, the battery will probably have to be changed to a 9.6 V or even 10.8 V.

Piston:
With stronger springs and tighter barrels, the physical strain on your piston and cylinder head increases. A piston can be equipped with a 'silent' or 'anti-vacuum' piston head. The silent piston head reduces the impact the piston makes in the cylinder and also reduces noise. The Anti-Vacuum piston head prevents the forming of a vacuum in the cylinder - this means that the barrel length can be extended without too much risk of the 'dreaded suck'.

Mechbox:
This is a totally new mechbox with new and better gears, stronger spring, nozzle and other improvements (see below). This isn't a cheap upgrade but the durability and lifespan increase and so do the pellet velocity and overall performance. A new mechbox isn't available to all models, like the FAMAS doesn't have an upgraded mechbox. There are different versions of mechboxes since they're used in different weapon models.

Quality control has appeared to have improved as well on current models for both brands.
• Version 1 is only used in FAMAS
• Version 2 is the most common and is used in M16, G3 and the MP5's
• Version 3 is used in AK47, MP5K & MP5K PDW and Sig SG550, Steyr AUG, 551 and 552 seals
• Version 4 is only used in the PSG-1 and is semi automatic
• Version 5 is used in the UZI and has the recoil system
• Version 6 is used in M1A1 Thompson and the P90
Resuming, the Mechbox is a completely upgraded gear-box system, normally including:
• Taper Spring
• Spring guide
• Air seal nozzle
• Bore-up Cylinder set
• Polycarbonate piston
• All helical gear set super torque up
• Oil-less metals
• Cut Off lever
• Selector plate
• Tappet plate
• Reversal stop latch
• Stopper arm
• Trigger
• Switch Assembly
• Reinforced anodised gearbox

Metal body:
Metal body upgrades are typically expensive, but the increased durability, weight and a more realistic appearance of the weapon are common reasons for upgrading to a metal body. Recently, many manufacturers such as Classic Army and ICS offer metal bodies as a stock feature on some of their products.

Metal Hop Up:
HopUp is the ability of a gun to put backspin on the BB as it leaves the barrel. This increases the distance the BB will follow a straight trajectory before the effects of wind resistance and gravity take over. This isn't equipped in all guns but is a purchasable upgrade.

BBs

The 6mm BBs themselves are also produced in various masses. Typically 0.12 g and 0.2 g BBs are used for spring pistols; 0.2, 0.23, or 0.25 g for AEGs and gas pistols; and 0.29 g, 0.3 g, 0.36 g, and 0.43 g for sniper rifles. Steel BBs weighing up to 0.88 g can also be used for target shooting, though they are not common. Recently, airsoft guns in Japan have been produced that are chambered for 8 mm diameter pellets. For the most part, these new guns are replicas of large calibre pistols and revolvers, partially for the reason that a 6 mm pellet on these weapons (ranging from .357 magnum and beyond) would be unrealistically small. The 8 mm pellets and guns are still comparatively very rare.

There have also been products made which do shoot spherical BBs. The best known of these is the Asahi 'Blade Bullet' BB, which are now extremely difficult to find and quite expensive to buy. These were designed to be shot from the short-lived Asahi M700 and M40 premier grade rifles, which were produced in 1993. Compatibility with other airsoft guns is highly limited, especially due to their inability to be used with Hop-Up.

BBs made of paint are available but are incompatible with guns that have Hop-Up as they break in the gun. Paint is very unpopular with airsofters because it tends to stain gear and clothes. Players that wish to use paint should check that it is ok with their fellow playmates. Most people would suggest you play paintball if you want to use paint BBs.

Pellet weights and their usage:
• 0.12 g Used by some gas and spring weapons. High velocity and low stability
• 0.20 g Standard weight for most weapons. AEG uses these or slightly heavier pellets
• 0.25 g Heaviest weight for standard AEG, BlowBack and Spring guns
• 0.30 g Standard weight for most sniper rifles
• 0.36 g Heavier pellets for sniper rifles. Very slow but high stability
• 0.43 g For the highest level of upgrades in spring and gas sniper rifles

Metal-coated and steel BBs are also available, but to be used for target shooting only. Graphite coated BBs are often used by snipers.

There is also available biodegradable BBs (usually in 0.20 g and 0.25 g) and tracer BBs (usually in 0.15 g, 0.20 g and 0.25 g);

Note: A recent study has shown that while some BB's are biodegradable, it doesn't necessarily mean it is environmentally friendly.

The majority of 'bio' BB's degrade into something like styrofoam, which isn't biodegradable.

Less common weights:
• 0.22 g Western Arms BBs for their gas blowback pistol series
• 0.29 g Maruzen’s BBs for their APS series

Physics of Airsoft

Pellet velocity vs. energy vs. weight:
The pellet velocity of automatic electric guns is determined in large part by the tension of their main spring and so there tends to be a stratification of values. The most common airsoft velocity limits are between 300 to 400 ft/s (90 to 120 m/s) for AEGs and 400-500 ft/s (120-150 m/s) for single shot guns (sniper rifles). Here are some common levels of airsoft gun pellet velocity.

Higher energy but different collisions read Elastic collisions topic for further information.
• 1 m/s = 3.281 ft/s
• 1 ft/s = 0.3048 m/s

Performance:

For the sake of a relative uniform standard, the usual BB mass used when determining pellet velocity is 0.2 g. Airsoft guns shoot 0.2 g BBs at velocities from 100 ft/s (30 m/s) for a low-end spring pistol, to 550 ft/s (170 m/s) and beyond for heavily-upgraded customized sniper rifles. Most non-upgraded AEGs using the Tokyo Marui system are in the middle, producing velocities from 270 to 300 ft/s (80 to 90 m/s), but upgrades to the internal components can increase the pellet velocity significantly. Because of their low mass, these BBs have very little kinetic energy on impact compared to paintballs, ranging from 0.5 to more than 6 joules (J). A typical paintball at 300 ft/s (90 m/s) produces more than 12 J. This makes the sport arguably safer than paintball although protective gear, especially for the eyes, is considered a requisite for safe play.

The total kinetic energy of a body (muzzle) can be considered (for non-relativistic mechanics) as the sum of the body's translational kinetic energy and its angular kinetic energy (also known as rotational energy). It's normal to find airsoft - kinetic calculations using only translational kinetic energy to simplify formula use.

Hop-up (High Operation Power UP) - Bernoulli's principle:

Bernoulli's principle is a physical law that says that if a bullet is given a backspin an overpressure is formed under the bullet and an under pressure is formed on the top of the bullet. These pressures affect the bullet as on an airplanes wings a lift is formed. The bullet is sucked up. If the Bernoulli principle is equal to the effect of gravitation the bullet will fly longer and straight until the bullet loses its energy and the Bernoulli principle stops working.

A significant development that has since been incorporated into almost all good quality mainstream airsoft guns has been 'hop-up.' This is a simple rubber piece around the chamber or rear of the barrel that is thicker on the top in order to provide a backspin on the BB as it exits. Consistent with Bernoulli's principle, this causes air above the BB to move slightly faster than the air below it, creating a measure of lift. The practical effect of this mechanism is immediately visible and quite effective. Using it can extend the range of an airsoft gun by up to 50%. Some guns feature an adjustment mechanism to increase or decrease the amount of backspin, which allows fine tuning of the lift generate to accommodate various BB masses. Hop-up also means that certain BB masses will not shoot in a relatively straight trajectory from certain guns - the hop-up produces either too much lift (causing the BB to 'float' as it flies forward) or too little (causing a premature end to its flight). So in the words of a 12 year old airsofter this means it puts a spin on the BB to change the pressure on the top and bottom to create lift.