These models can vary from low/middle end to very high end. The lower end models are usually gas operated, nonblowback. Higher models can include rifles or SMG (SubMachineGun). In the fixed slide or non-blowback type of gas operated guns there is a gas chamber that is reloaded after shooting several magazines. The gun is capable of semi-automatic and/or full automatic fire. In the gas blowback type, the slide moves back and forth like in a real gun when shooting. There is distinct recoil and gas chamber located in the magazine. This type of gas operated air gun is very realistic both in feel and action.