Electric airsoft guns that are built with a metal gearbox are far more superior than versions containing plastic gearboxes. The main vantage points are: power, rate of fire, and durability. With the increased strength that metal gears give, it allows for a better power unit or motor. Plastic gears can easily be broken, warped, and melted but are cheaper in overall price. An electric airsoft gun with a metal gearbox shoots at 330 to 600 FPS with .20g bbs vs a plastic gearbox gun that shoots at 140 to 300 FPS with only .12g bbs. The rate of fire (ROF) for a metal gearbox rifle is 900 to 1500 RPM (rounds per minute) while the plastic gear rifles range from 150 to 400 RPMs.