CO2 in Airsoft Gun: How Long does it Last and other FAQ


CO2 airsoft guns are known to be a great choice for airsoft players and anyone that wants to have fun shooting in their backyard. Such guns are one of the most common types of guns on the market and are powered by CO2 cartridges.

Very often there are questions asked by beginners and people who do not know much about how a gun itself works inside.

The goal of this post is to answer such questions and provide you with all fundamental knowledge that one must acquire in order to safely use their CO2 airsoft gun.

You can also check my post on the difference between CO2 and green gas if you want to expand your knowledge on gases used in airsoft.

How Long can you Leave CO2 in your Airsoft Gun for?

It is recommended to use the entire CO2 cartridge in one usage if possible, meaning that once you decide to shoot from your airsoft gun, you shoot it until there is no gas left in the cartridge. If you keep it lubricated it can remain for weeks within but it is not considered the best practice.

It is the recommended way, not always a must-to-follow way! Your gun will probably be fine even if the cartridge remains in for a few days up to a week or two, but the longer it goes without lubrication, the greater the odds for it to damage your gun are and eventually everything will dry out.

You will want to check out the lubricants that are a must for airsoft gun maintenance and use them regularly.

If you have ever wondered what is it like to crush the CO2 cartridge

Is it bad to leave CO2 in Airsoft Gun?

If you leave CO2 in your gun for long periods of time (it may be more than a couple of days or more than a couple of weeks depending on the quality of the gun and other environmental conditions) it may cause leaking of the gas and may destroy your gun from within.

The reason that leaving CO2 in your gun is bad is that once you break the seal on the cartridge and place it in, It causes the pressure that interacts with the inner gun parts.

However, some people keep it inside their gun for a week, two or more in order to preserve some gas.

CO2 is not expensive but it adds up in the long term. If you want to do this then you should put some lubricant on the top of the cartridge when inserting the cartridge in order to make sure that the CO2 pressure does not dry the seal out and eventually wear it out.

Can you remove a CO2 Cartridge from a gun and use it later?

If the seal has been broken and that means that you have already placed the cartridge in your gun, removing it and then using it later will not be possible.

Suspecting that your cartridge is full of CO2 and you attempt to remove it, you will lose all the remaining CO2 stored inside.

It will start leaking and you will not be able to prevent it, so use the entire cartridge before removing it and replacing it with a new one.

How long do CO2 Cartridges last in Storage?

The CO2 cartridges in theory do not have an expiration date, therefore you will be able to use them even after years of having them waiting in the storage room. This may be risky though and you should rather buy some new ones.

Although they can last for so long you need to pay attention whether it is damaged or not.

A damaged one will leak the gas and lose the pressure, such ones will not be usable.

Also, check whether your cartridge has been affected by corrosion or not.

If you have stored them in wet conditions the chances are that there is some corrosion on them and then it is suggested to throw them away.

High temperatures and the direct impact of the sun can furthermore increase the odds of the cartridges explode.

For the best practice keep them out of the heat in safe dark places.

Can you Refill CO2 Cartridges?

Once you have used your cartridge it will no longer be usable.

You will have to use a new, unsealed one. This goes for most of those small cartridges that you are probably using in your pistol.

The pressure can not be set up just like that and requires manufacturing tools. Once the seal was broken it is no longer welcomed for refilling.

I would not suggest you try to refill it on your own because it is dangerous and it may cause an explosion.

The bottles are legally required to have a single on-use relief called a ruptured disc that prevents explosion from happening before the pressure gets high enough.

However, there are some bigger gas tanks that can be refilled, and if you check out your model you will find out whether it can be refilled or not.

If you want to refill cartridges you should realize that they are mostly for one-use only, they are cheap and there is no purpose in refilling them.

If you want to be able to refill CO2 then check out the CO2 Tanks, they certainly can be refilled.

It is recommended to handle it to someone who fills cylinders daily for a job. CO2 tanks can be refilled mostly at local welding supply stores, fire extinguishers refill places, sporting stores, or similar companies that offer the service.

How many shots can you get out of a CO2 Cartridge?

In order to answer such questions, we would need to have an exact model of a gun knowing all the properties of the gun.

It may greatly vary from gun to gun because some guns use more power than others.

In short, if your gun has the blowback mechanism within it, it is naturally going to use my CO2 to power the sliding mechanism than it would be the case with a non-blowback version of the gun.

The second important factor is the power of the gun, whether it shoots at higher or lower fps, more power that comes from the gun means more power required to run it.

CO2 also behaves badly when a gun shoots rapidly and efficiency goes down when the temperature around is low.

This happens because it requires too much heat in order to function properly and sometimes the environment does not provide it. This is often an issue when players play outside games in winter times.

I have calculated the average on which guns may perform in terms of shot BBs per cartridge used.

A GBB pistol may shoot 80-120 BBs or 2-3 magazines per CO2 cartridge on average, but the numbers may be higher than that or lower depending on given factors in the environment and properties of the gun.

Another non-blowback pistol may shoot 200+ BBs on a single cartridge in the same environment just because it does not need more power to power the sliding mechanism.

Both guns if shoot rapidly may lose 20-30% in efficiency.

Are CO2 Cartridges safe?

If you try to manually refill the seal-broken cartridges it may cause a small but dangerous explosion, however, if you attempt to inhale it, it may cause additional health problems because CO2 prevents the oxygen from flowing to the brain and it may lead to brain damage.

This is not a case that happens often because if your CO2 cartridge starts to leak you are naturally going to step away.

If this happens indoors, open the windows and the doors and let it do the job for a few minutes.

The small amounts of CO2 that are stored in cartridges for airsoft guns use are small and thus not very dangerous, however theoretically speaking, if you would be closed in a 2×2 sized room without any ventilation system, it could hurt you.

Final take on

I hope I managed to answer some of the most common questions regarding CO2, as you can see it is not rocket science but understanding the basics is always important.

If you need help finding good CO2 cartridges, you can find them on Amazon.

Crosman is a decent manufacturer that’s been on the market for a while!

Recommended books to skyrocket your airsoft experience and skills

The first book of the airsoft bible teaches you adapted tactics that work within the field which are based on real military tactics.

The second book will teach you and your team about the essential skill of communication (necessary for team synergy and this is exactly what separates great teams from average).

Recent Posts