The choice of propellant determines both how hard AIRSOFTa shooter and how long it lives. The wrong gas can crack a plastic slide or wear out seals in a season. Here's the difference between green gas, red gas and CO2 — and what you should drive in the Norwegian climate.
What is the difference between green gas, red gas and CO2?
All three operate the same: a piston that sends the bullet out and the slide back. The difference is the pressure.
- Green gas Typically around 135PSI. The standard choice, and what most guns are designed for.
- Orange or mid-power around 164PSI. An intermediate step when green gas becomes too weak.
- Red or black gas around 178PSI. For metal slides and rifles.
- CO2 in 12g cartridge is many times higher, and is used in weapons built for it.
The figures above are taken from our own gas cylinders. Specifications vary between manufacturers, so check the cylinder rather than relying on the color alone.
What gas can your weapon withstand?
This is the most important rule, and it is absolute: Never use red or black gas in a gun with a plastic slide. The high pressure can crack the material. If the weapon has a metal slide, it can usually withstand higher pressures — but check the manufacturer's instructions first.
A weapon designed for green gas will not be improved by more powerful gas. It will only wear out faster.
What about cold?
There is a lot of misinformation circulating here, so let's be clear: CO2 is more stable in the cold than green gas, not less.
Green gas loses noticeable pressure when the temperature drops below 10°C. The magazine doesn't get enough power to cycle the slide, and you get short shots and misfires. This is called cool-down, and is exacerbated by rapid firing because the gas cools itself down as it expands.
CO2 keeps the pressure down to freezing point much better. If you play outside in the Norwegian autumn and winter, CO2 or red gas is what actually works.
CO2 cartridges: 12g and 88g
The 12g cartridge is the standard in AIRSOFTmagazines and in most air pistols and CO2 air rifles. It is punctured when you screw it on, and deflates through use — or over time if a gasket leaks.
- 12g CO2 cartridges, 25pcs — the size most people go for
- 12g CO2 cartridges, 100pcs bulk pack — for those of you who shoot a lot
- 88g CO2 cartridge — for weapons with large CO2 tanks
Never leave a punctured cartridge in the magazine for any length of time. The pressure keeps the seals constantly under stress, and a forgotten cartridge is the most common cause of leakage.
Cleaning cartridges — what people forget
A cleaning cartridge contains silicone instead of pure CO2. Running one through the gun at regular intervals will lubricate the valves and O-rings from the inside in places you wouldn't otherwise be able to reach.
CO2 is a dry gas and does not carry lubrication like silicone-added green gas does. Therefore, CO2 guns need this more than gas guns do.
Gas cylinders we carry
- Ultrair Green with silicone, 570ml 135PSI — the default choice, lubricates while shooting
- Ultrair Orange Mid-Power, 570ml 164PSI
- Ultrair Red High-Power, 570ml 178PSI — only for metal slides
- Specna Arms Vapor Green, 600ml
Look for bottles marked with silicone. The gas will then carry lubrication into the mechanics, and you won't have to lubricate the seals as often.
Maintenance that actually matters
- Fill with the bottle upside down. This will get liquid into the magazine, not just steam. Fill until the sound changes.
- Keep the magazine half full. A completely empty magazine allows the seals to dry out, a full one keeps them constantly loaded.
- Drop dry shots. Shooting without bullets wears out valves and nozzles.
- Do not leave the magazine in the sun. The pressure rises, and the pressure relief valve releases the entire charge.
- Let the weapon rest between series. Rapid firing cools the magazine and results in decreased performance — not a sign of failure.
- Lubricate the seals in the bottom, top and valve with silicone oil at regular intervals.
- Use good quality bullets. Cheap BBs with casting seams struggle with barrel and hop-up.
Frequently asked questions about propellant gas
What is the difference between green and red gas?
Pressure. Green gas is typically around 135PSI and is the standard choice for most pistols. Red gas is around 178PSI and should only be used in weapons with metal slides.
Can I use red gas in my gun?
Only if it has a metal slide. The high pressure can crack a plastic slide. Check the manufacturer's instructions if you are unsure.
Is CO2 or green gas best in cold weather?
CO2. Green gas loses noticeable pressure below 10°C, while CO2 remains stable much lower. For winter games in Norway, CO2 or red gas is what works.
How long does a 12g CO2 cartridge last?
It varies with the weapon, temperature and rate of fire. A punctured cartridge should not remain in the magazine for long, because the pressure keeps the seals stressed and leads to leakage.
What is a cleaning cartridge?
A CO2 cartridge with silicone instead of pure CO2. It lubricates valves and O-rings from the inside, and is especially useful on CO2 guns because CO2 is a dry gas with no inherent lubrication.
How do I fill the gas tank correctly?
Hold the bottle upside down and fill until the sound changes. This will allow liquid to enter the magazine instead of steam.
See the full range of gas, CO2 and accessories. Read also about which BB weight should you choose and the best blowback pistols.
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