Airsoft Gun Parts & Upgrades

Airsoft Gun Parts & 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% extra velocity. The downside is that the barrel clogs up more often and has to be cleaned. A longer barrel increase 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 mA·h, while the other small standard batteries have capacity of 600 mA·h. 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 mA·h), 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 (mA·h), 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.

Version 1 is only used in FAMAS.
Version 2 is the most common and is used in M16, G3 and the MP5s.
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

For TM Mech Box Version 2 and 3 Disassembly Instructions check external links section for Francis Zhou (skyfire) translation of the "Airgun Custom Parts Catalog '98" by Seibido Mook in Japan.

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 now 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 up