Airsoft gun pellets come in different shapes, sizes and weights. Most airsoft pellets, also known as BBs (ball bearing) are normally 6mm spherical plastics. There are starch based biodegradable, metal coated, graphite coated, and steel pellets. Airsoft pellets typically weigh from 0.12 to 0.43 g.
6mm pellets, 0.12 g are used by gas and spring weapons but not for high-end AEGs. The same goes for 0.15 g. 0.20 g standard weights and used by AEGs. 0.23 g is heavy weight for AEGs and 0.25 g is the heaviest weight for standard AEGs, blowback and spring guns. 0.30 g is the standard and 0.36 g are heavier pellets for sniper rifles. 0.43 g is for highest levels of upgrades sniper rifles. As for 8mm pellets, 0.34 g is low weight, 0.45 g is standard weight and 0.60 g is the heaviest weight for 8mm sniper rifles. Airsoft Guns are designed to apply a counter-spin to the pellets as over long distance wind resistance will naturally curve the pellet whilst it travels. This Counter-Spin increases the accuracy and the integrity of direction over longer distances.
For automatic electric guns (AEGs), the velocity limits range between 300-400 FPS (feet per second). For single shot guns, it is 400 to 500 FPS. The tension of the main spring determines the pellet velocity of automatic electric guns (AEGs), so there tends to be a stratification of values. Low-end spring pistols can shoot 0.2 g BBs at velocities from 100 FPS. The range for high-end airsoft guns can reach 550 FPS. Anything beyond this would need a major upgrade of internal components. This internal modification can also increase the ROF (rate of fire) drastically.
Airsoft pellets may not damage the skin but are extremely dangerous to the eyes, so goggles or other protective gear must be worn at all times while playing airsoft sports.