How To Fill an Airsoft Gas Magazine (Step-by-Step)

Airsoft guns are imitations of real guns that use gas compression to shoot BB ammunition. The propellant gas stored in an airsoft gun decreases for every shot made, so it needs to be refilled when it’s drained out. However, there are some technical details you need to consider whenever you need to supply the gas magazine to maintain your airsoft gun’s shooting performance.

Here’s a step-by-step on how you can fill an airsoft magazine:

  1. Prepare the required materials.
  2. Insert the gas nozzle into the fill port.
  3. Apply pressure onto the gas container.
  4. Repeat the procedure until the magazine is filled.
  5. Return the airsoft gun to its initial settings.

Filling the gas magazine of your airsoft gun is one of the fundamental skills of an airsoft gun user. Whether you’re a professional player or just playing random skirmishes with your friends,  mastering the basics is essential to effectively utilize your airsoft gun. In this article, I’ll discuss the steps above and guide you on how to fill your airsoft magazine.

1. Prepare the Required Materials

To correctly fill the airsoft gun magazine, you’ll need to prepare two basic things.

Airsoft Gun Magazine

To fill the gas magazine appropriately, you need to remove it first from the airsoft gun. You can’t fill this up with gas propellant if it’s still attached to the weapon. Now, if you’re a newbie and don’t know how to remove the gas magazine, simply follow these procedures:

  1. Hold the airsoft gun with your right hand as you usually would when trying to aim.
  2. Hold the magazine with your left hand. This is to prevent the magazine from dropping to the ground when you push the release button.
  3. Push the release button near the thumb of your right hand. Then get the gas magazine.

Gas Propellant

This is usually purchased from a local airsoft gun store. And if this will be your first time buying a gas propellant, there are things you need to know before rushing yourself to the store.

First, you need to know what type of gas your airsoft gun needs. There are three kinds of gas airsoft guns classified depending on the type of gas it needs, and this includes CO2 cartridges, green gas can, and propane. 

In most cases, you can’t feed your airsoft gun with a gas that it’s not designed to fill with. And this could damage your airsoft gun if you fill it with the wrong type of gas propellant.

CO2 Cartridges

CO2 means carbon dioxide gas. This type of gas produces a higher pressure rating even in low volumes. So usually, they’re stored in a small stainless metal cartridge that can easily fit inside the gas magazine.

The CO2 cartridge is a non-flammable gas filled with 12 grams (0.42 oz) of pure carbon dioxide that can pressurize an airsoft gun with approximately 800 psi under average temperature.

Unlike other gas propellants, CO2 cartridges are more convenient to fill in a magazine. You just need to put the entire cartridge into the magazine’s CO2 hatch, close it using the magazine key, and you’re ready to use it again.

Reload time for CO2 airsoft guns goes around a minute, which is faster than green gas airsoft guns.

Video: Filling Airsoft Gas Magazines Correctly

Green Gas Can

Some places would refer to this gas as HFC22, so just note that up when buying this gas propellant. Green gas produces a lower pressure in airsoft guns. The gas cans contain a range of sizes, usually around three hundred milliliters to a liter (10.14 to 33.81 oz). And an important thing to note about green gas is that they’re pressurized flammable gases.

A flammable gas comes with some preventive warnings that you need to note when using this kind of gas propellant.

  • Never inhale its gas. So, you should also use it in a well-ventilated area to prevent it from stacking up.
  • The can is pressurized. So, don’t place it under direct sunlight or heat. This will result in a pressure build-up that’ll make it explode out of the can.


This type of gas is only an alternative for the green gas canisters. If there are no local airsoft stores with green gas available, you can use this temporarily. However, it’s not for long-term usage since it will gradually damage your magazine if you constantly use it.

Now, to appropriately fill your magazine with propane, you’ll need to have an essential tool since propane isn’t stored in an airsoft gun-friendly storage like the CO2 cartridge and green gas canister. This tool is the propane adapter, and it attaches the widespread green or blue propane tanks found at any hardware supplies or home improvement center.

Overall, propane gas is the most affordable type of gas you can use to load up your gas magazine. But you should remember to only use it sparingly, as it can break the magazine of your airsoft gun. As a rule of thumb, you can use it alternatively with green gas canisters and never use it straight up.

A frequently asked question about gas propellants is if they can use green gas canisters to load a CO2 Airsoft gun.

In general, you can use this canister as long as it’s compatible with the design of your airsoft gun. If the airsoft gun is designed to be fed only with CO2, there’s no way you can feed it with other types of gases. But some airsoft guns have a different design to receive green gas or even propane gas. In that case, you can feed it with green or propane gas.

One word of caution, though. Even though you can load green gas to a CO2 airsoft gun, you can never do it the other way to a green gas airsoft gun. This is because green gas has a lower pressure rating than CO2, which means the magazine and the gun are designed to receive only the pressure of green gas.

Therefore, when you load the CO2 gas to a green gas airsoft gun, it’ll either be broken or explode, so be careful not to do this.

Here you can find a guide on how to make your own propane adapter for airsoft.

2. Insert the Gas Nozzle Into the Fill Port

Once you already have the required materials to fill up your gas magazine, the next step is to correctly feed it with the gas container.

To do this, just take the green gas can and remove its cap. You should see a small nozzle for the gas to come out. Take your magazine out and place its fill port on top.

Insert the gas nozzle into the fill port. You need to make sure that the gas container is vertically aligned with the magazine. Don’t incline it on any other side. 

When you tilt the gas container on any side, there will be some gas spill since the nozzle isn’t inserted correctly into the feed port. Also, this can damage the small nozzle of the can. Once it’s broken, pressure may be released out into the surroundings, or you may not be able to use the container anymore.

Another reason why you need to vertically align the gas container is that it contains a mixture of green gas in liquefied form and in evaporated form. And the liquefied form is what you need to fill in the magazine.

If you want to learn more about inserting the gas nozzle into the fill port, you can watch this short video from HowcastSportsFitness:

This video also discusses CO2 cartridges and how to adequately load the cartridge in your airsoft gun’s magazine for better understanding.

3. Apply Pressure Onto the Container

To extract the gas out of the container, you need to apply pressure onto the gas can. You can do this by gently squeezing the gas container while its nozzle is inserted into the fill port of the magazine.

Just remember to do this procedure for about three to five seconds only. Don’t exceed too long in squeezing the container to avoid unnecessary gas spills from the container. This is because when you press the container into the magazine, the gas will be in evaporated form. So, you’ll need to wait for it to come back to its liquefied state.

You might be wasting too many green gases if you apply pressure on the container for longer than five seconds. Simply wait for around ten seconds before squeezing the gas can again. This will give some time for the green gas to return to its liquefied form while inside the magazine. 

Once it’s back to its liquefied state, you can resume applying pressure on the container.

4. Repeat the Procedure Until the Magazine Is Filled

After waiting for around ten seconds, the green gas container should be ready to be squeezed again to extract gas out of it. Repeat the procedures stated earlier to completely fill the gas magazine of your airsoft gun. You’ll notice that it’s already filled up when the green gas spills out of the container.

Try to check first if the container leaned on any side or isn’t vertically aligned with the magazine. In that case, the gas will indeed spill out of the can when applied with pressure.

You need to make sure that you’re doing this step correctly because the spilling of the gas could also be an indicator that the magazine is completely filled up.

Once you’ve done all the procedures completely and correctly, while the gas still spills out of the container and from the magazine, it only means that the magazine is already full.

At this point, you can now stop squeezing the container.

5. Return the Airsoft Gun to Its Initial Settings

After filling up the magazine with green gas, you can now load some BBs into the gas magazine. Then insert it back to the magazine hatch of your airsoft gun. Just remember to hear a clicking sound when you return it, as it indicates that the magazine is correctly inserted into the hatch. And then you can now try to test your airsoft gun.

Testing your airsoft gun after filling a gas guarantees that you did all the procedures correctly and successfully loaded the magazine with gas. To try your airsoft gun, simply aim it at a specified target, then pull the trigger for a few shots. 

You’ll know that the airsoft gun has enough pressure when the BBs that were shot out can reach the same distance that the weapon is designed to. When you see this indicator, then it only means that the magazine has enough pressure inside.

Also, remember to put the cap back into the gas can. Because if you forget or intentionally didn’t do this, the gas inside will be released out quickly to the surroundings. Sooner or later, the newly purchased green gas can is already empty if you habitually don’t return the cap. 

As a worst case scenario, this may cause a fire incident near the gas container because of gas spills. So, to prevent any of these from happening, make sure to return the cap back to its proper place after usage, and everything should be A-okay.

Now, to help you visualize the procedures, you can watch this short video from Socom Tactical. It can help you familiarize yourself with the typical steps you need to do in filling an airsoft magazine with gas:

These steps can only be performed using Gas Blow Back airsoft guns or GBBs since these guns have magazines with gas chambers and will require gas to shoot the BBs out. Other types of airsoft guns, such as electrically operated, will have a different set of procedures. So just take note of it if you have a variety of airsoft guns available at your house.


Airsoft guns have developed through the years. It started from spring operation to electric and to gas pressurized.

Gas pressurization of airsoft guns immensely increased its shooting performance. However, the pressurized gas inside the magazine is decreased for every shot made. This makes the gas consumable, similar to BBs, so make sure that you store many gas containers at home.

Just remember that a gas-pressurized airsoft gun comes with responsibilities and proper handling since the gas is flammable and toxic. Therefore, you need to correctly follow all the procedures stated earlier to prevent unnecessary accidents and waste of gas.