GNB

Gas Non Back. This construction is generally used for airsoft gas pistols, but also some types of rifles. For propel GNB serves propellants like GreenGas, HFC 134/144a or CO2. This is easily filled from the external bottle to the reservoir, or in the case of weapons CO2 used single replaceable cartridge.

These guns have not moving slide and they have always tougher trigger than GBB models. The advantage over a system with BlowBack usually achieve higher muzzle velocity and far less gas consumption. Guns are not generally suitable for colder weather since then threaten to gas leaks or other defects, and various disfunctions.

Guns type GNB require regular maintenance and lubrication.