Gear Box
When deciding on an electric airsoft gun arguably the most important component of the gun is the gearbox. An electric gun's gear box is subject to the most wear and tear. The electric motor turns a set of gears which forces a spring to compress a pneumatic cylinder. In a gun with a high rate of fire combined with the larger spring and cylinder needed to produce a high muzzle velocity the gear box can be placed under a lot of stress. This is why most competitive airsoft gun enthusiasts choose a gun with an all metal gear box. An all metal gear box will usually cost more than an all plastic or partially plastic assembly but the reliability and gun life will be greatly increased.