AEG, gas or CO2: which airsoft gun to buy
Three ways of pushing a plastic ball down a barrel, and the choice between them decides more about your day than the make on the side does. This is what separates them, and which one to start with.
The short answer
If this is your first gun, buy an AEG. Electric guns are the default for a reason: they work in any weather, the running cost is almost nothing, parts and upgrades are everywhere, and they do not punish you for not knowing anything yet.
Gas blowback is the enthusiast's choice and the realistic one. CO2 is the cold weather and pistol answer. Both are better bought second, once you know what you want from them.
Electric, the AEG
A rechargeable battery turns an electric motor, the motor drives a gearbox of three gears, and the gearbox compresses a spring behind a piston. Release the piston and it pushes a column of air that pushes the BB. Then it does it again, as fast as the motor turns.
Batteries are usually NiMH packs from about 7.2 to 12 volts, or increasingly lithium polymer, which are lighter and hold more. Higher voltage means a faster rate of fire, higher capacity means a longer day before a swap.
What makes it the sensible default: it does not care about the temperature, a day's shooting costs a charge and a bag of BBs, and almost every part is available because almost everybody runs one.
What it is not: realistic. There is no recoil, the noise is a whirr rather than a crack, and the magazine holds far more than the real thing ever did. If that matters to you, read on.
Gas blowback, the GBB
Gas sits in the magazine. Pull the trigger and a valve releases it: some of it drives the BB, the rest shoves the slide or bolt backwards, which gives you recoil and cycles the next round. That is the whole appeal - it moves in your hand the way the real thing does.
The gas is almost always green gas, which is propane with a little silicone oil in it to keep the seals fed. Other gases exist: HFC-134a runs at lower pressure and suits plastic-slide pistols, and so-called red gas runs high enough to damage guns and is generally avoided.
The costs are different from an AEG. Gas is a consumable you keep buying, magazines are expensive because each one is a pressure vessel rather than a box of springs, and the mechanism is more complicated so there is more to go wrong.
Firing fast works against you. The liquid propellant cools as it expands, the magazine gets cold, and the rate of fire and power both drop until it warms up again.
CO2
Same idea as green gas, much higher pressure. Green gas is commonly quoted at somewhere between 115 and 150 psi at room temperature; CO2 at somewhere between 700 and 850. Those figures come from retailers rather than from a standard and they do not agree with each other, so treat them as an order of magnitude rather than a specification. The part everybody agrees on is the one that matters: CO2 is several times the pressure.
That buys you more power, a harder kick and far better cold weather behaviour. It costs you wear - higher pressure is harder on every seal it passes - and it costs you compatibility.
The compatibility point is the important one. A magazine built for green gas is not built for CO2 pressure. Do not put CO2 through a gun or magazine that is not rated for it.
The British winter question
This is the one that decides it for a lot of people here, because most UK skirmishing happens in weather that gas does not enjoy.
Green gas is propane, and propane's vapour pressure falls as it gets colder. Below about ten degrees the slide gets sluggish and the velocity drops. In a hard frost a gas pistol may give you a shot or two out of a full magazine and then very little.
CO2 copes considerably better, and is the usual recommendation for winter play, but it is not immune - sources put its comfortable floor somewhere around freezing, and rapid firing still chills the magazine enough to stiffen seals.
An AEG does not care. A battery loses a little capacity in the cold and that is the end of the story. If you only own one gun and you play through a British winter, this is the argument for it being electric.
Spring and HPA, for completeness
Spring guns are cocked by hand for every shot. Cheap, simple, immune to weather, and single-shot - which is why they survive mainly as sniper rifles and as a first sidearm.
HPA runs the gun from a bottle of compressed air on a hose, with a pneumatic engine in place of the gearbox and an electronic unit controlling how much air each shot gets. It is the most consistent and adjustable system there is, and it is immune to the freezing that affects liquid propellants. It is also the most expensive and you are tethered to a tank.
What it costs to keep running
An AEG: a battery charge and BBs. Effectively nothing per game once you own the gun and a charger.
A gas gun: BBs, plus gas you keep buying, plus magazines that cost real money and perish eventually.
CO2: BBs, plus capsules, which are cheap individually and add up, plus the same magazine problem with more pressure behind it.
None of this is an argument against gas. It is an argument for knowing what you are signing up to before you buy the second magazine.
What is actually on these shelves
Mostly AEGs, by a wide margin. A handful of gas blowback guns, and usually only one or two CO2. That is a reflection of what players buy and then sell on rather than a preference, and it is worth saying plainly: if you have decided you want gas specifically, there will be less here to choose from.
What this guide does not cover
What is wrong with a particular second-hand gun - what wears out, what to ask and what to look for - is the subject of the guide on buying a used airsoft gun, and is not repeated here.
The legal side, including muzzle energy limits and who may buy a realistic imitation firearm, is in the airsoft law guide.
Questions
- Which type of airsoft gun is best for a beginner?
- An AEG. It works in any weather, costs almost nothing per game to run, parts are everywhere, and it does not need you to understand it before it will work. Gas and CO2 are better second purchases.
- Is green gas or CO2 better in cold weather?
- CO2, clearly. Green gas is propane and its pressure falls as the temperature does - below roughly ten degrees you will notice sluggish cycling and lost velocity. CO2 runs at several times the pressure and copes down to around freezing, though rapid firing still chills the magazine.
- What is green gas?
- Propane with a little silicone oil added, which lubricates the seals as it passes through. It is the standard propellant for gas blowback airsoft guns.
- Can I use CO2 in a green gas magazine?
- No. CO2 runs at several times the pressure green gas does, and a magazine not built for it is not safe to use with it. Use only the propellant the gun and magazine are rated for.
- Do used AEGs come with a battery?
- Often not. Check before you buy, and check which connector it uses as well - older guns use a small white Tamiya plug and most people have moved to Deans.
- Which is the most realistic?
- Gas blowback. The slide or bolt actually cycles, so you get recoil and a realistic noise, and magazine capacities are closer to the real thing. That realism is the entire reason to accept the extra cost and the cold-weather problem.
Sources
In the shop
The guns on the shelf, by what drives them:
Written by the person who sorts the stock, not by a copywriter. Corrections are welcome at [email protected].