What is a gas gun?
A gas gun is any gun that uses compressed gas of some kind in order to fire an airsoft projectile. Primarily available as pistols (gas rifles are very rare) gas guns are available in many designs, but not as many as spring pistols. Gas guns come in two varieties: Blowback (GBB) and Non Blowback (NBB). Blowback refers to the slide of the gun cycling back with every shot like it does on real pistols. The slide on a NBB gas gun does not move during shot. Gas guns, particularly Gas Blowbacks, require more maintenance than any other type of airsoft gun because of the many moving parts and the necessity of keeping compressed gas securely sealed. Despite this, gas guns are very popular because they offer the most realistic replica and action of any airsoft gun and because they have, on average, a higher velocity than any other class of gun out of the box.
