Handgun, airsoft version, as called Gas Blow Back (GBB) operate with a reserve of gas contained in the magazine (mostly). Thus, discover our various articles which will be adapted to this type of replicas. Several types of gas are available, in order to be able to adapt the force of the gas to the mechanism: an ABS replica will support less the pressure.
To fill your magazine, be sure to put them upside down, valve up; and with the bottle upside down, filling valve down.
CO2 capsules of 12g (sold by 10) will allow you to use your airsoft guns for this special type of propulsion.