Gas AirSoft Guns & Sniper Rifles
Truly the most effective in AirSoft gun performance runs on a gas driven mechanism. Models utilizing such a compact operation include a large line of automatics, revolvers, and rifles. All are manufactured to a high degree of surface detail and dimension. Sub-categories of gas powered AirSoft guns include "Non-Blowback" and Blowback" models. Function and realism is experienced much better with the action of "Blowback" gas guns that are not only more powerful, but heavier in weight. Low-temperature carbon dioxide (CO2), Freon, and "green gas" are the most popular of gases used. The gas is either injected into a reservoir chamber within the gun or attached to an exterior assembly containing the gas canister and an expansion tank. Activated by the trigger, gas is released at a valve atop the reservoir or from the expansion tank, depending on the design. The small amount of cold gas reacts with the warmer atmosphere, expands instantly, and is channeled through a directed nozzle at the BB. The resulting pressure launches the BB out of the barrel toward its intended target. The label "Gas Gun" will be used to address any gun with this type of design mechanism in the AirSoft category.
The latest AirSoft gas operation incorporates the "Blowback" effect; a simulation of the slide action in actual gun firing. Essentially, the Blowback effect is created by directing the gas to an interior chamber within the slide of the AirSoft gun, causing it to move rearwards from the expanding gas, hence the "Blowback" action. The slide compresses a metal spring, which forces it to move forward as the gas escapes. In its movement, a BB is collected from the magazine and placed into the barrel, and readies the gun for the next trigger pull. Being a highly modified Gas Gun, this class of AirSoft gun will be identified as a "Gas Blowback" AirSoft Gun. All gas guns that do not incorporate this type of gas actuated slide mechanism will be labeled simply "Gas Gun" or "Gas Non-Blowback" AirSoft Gun.
To load gas hold both Green gas canister and AirSoft gas magazine upside down, insert canister nozzle into the gas charging port on the bottom plate of the gas magazine. Make sure valves match and is aligned. Press down on the gas canister in 3 short jabbing motions. This should adequately charge the gas reservoir inside the magazine. Each charge should be good for 2 - 3 fills of BB’s. Pressurized gas is cold, keep hands away from the immediate surrounding of the gas port when charging. Do not continuously recharge the magazine when it gets too cold. Rotate magazines or let the magazine warm up before recharge. Leak could occur if seals are frozen or cracked.
Before firing:
1. Chamber the first round of BB by pulling the slide back.
2. Pull the trigger to shoot, "Blowback" action will cycle the slide back and load the next round.
3. Slide will lock open when all rounds are fired.
From : http://airsoftguns.net/