AEG vs GBB vs NBB vs CO2 vs spring vs HPA: airsoft power systems explained

AEG: electric

In an AEG (automatic electric gun) a battery-powered motor turns the gears of the gearbox, which pull back a piston and compress a spring. When released, the piston pushes the air that fires the BB. Semi and full auto.

• Pros: reliable, work in the cold, cheap to run, huge choice of parts.
• Cons: need a battery (and charger), recoil absent or simulated.

AEPs are electric pistols on the same principle, smaller and weaker. Some AEGs have EBB (electric blowback) that moves the bolt to simulate recoil.

GBB and NBB: gas

The magazine holds liquefied gas (green gas or propane). On each shot a valve releases a little gas that fires the BB. In a GBB (gas blowback) some gas cycles the slide or bolt, like a real firearm: the most realistic type. In an NBB (non blowback) the slide stays still: less realism, less gas.

• Pros: realism, no battery, simple maintenance.
• Cons: gas loses pressure in the cold and performance drops, gas costs, pricier magazines.

GBB pistols under 1 J

• ASG CZ P-10C Full Polymer Gas Dual Tone FDE 0.90 J · 680 g
• ASG M9 IA Gas 0.81 J · 890 g
• Tokyo Marui Glock 18C GBB 0.78 J · 698 g
• Tokyo Marui Hi-Capa 4.3 D.O.R 0.73 J · 801 g
• G&G GTP 9 0.84 J · 770 g
• G&G GPM92 GP2 Walnut Wood Grip 1.00 J · 1010 g

CO2

They work like gas guns but use carbon dioxide cartridges (usually 12 g) in the magazine or grip. CO2 runs at higher pressure and is less affected by cold; that's why many CO2 guns are faster: always check the joules.

Spring

You cock the spring by hand before each shot (bolt, pump or slide). No battery, no gas: they always work and are quiet. It's the typical system of bolt-action sniper rifles and pump shotguns, and of budget pistols.

Spring rifles under 1 J

• ASG Steyr SSG 69 P2 Spring Black 0.90 J · 2500 g
• KTW Winchester M70 New Black Shadow Air Cocking Rifle 0.84 J · 2690 g
• Tanaka Works M700 AICS Sniper Rifle (Green / 24 inch) 0.75 J · 4500 g
• RWA Lee Enfield No.4 0.73 J · 3150 g
• Tokyo Marui VSR-10 G-SPEC Sniper Rifle (Spring Power) 0.70 J · 2090 g
• Tokyo Marui VSR-10 G-SPEC Sniper Rifle - OD (Bolt Action) 0.70 J · 2090 g

HPA: external compressed air

HPA (high pressure air) guns use a compressed air tank connected by a line and a pressure regulator; a pneumatic engine replaces the gearbox. Very consistent and tunable. Because power is set by pressure, always chrono them.

Which one?

To start, almost always an AEG; a GBB pistol as a sidearm; spring or DMR only if you want the marksman role. More in the first gun guide.

FAQ

What is the difference between GBB and NBB?

Both run on gas. In a GBB (gas blowback) the slide or bolt cycles on every shot, like a real firearm; in an NBB (non blowback) it stays still: less realism, lower gas use.

Do gas guns work in winter?

Less well: cold lowers gas pressure, so the gun shoots weaker or jams. CO2 is less affected than green gas. AEGs and spring guns don't have this issue.

Does an HPA gun stay within power limits?

It depends on the pressure set on the regulator: it can be adjusted, so it must always be chronographed like any other gun.

What is an AEP?

An automatic electric pistol: same principle as an AEG, with a small battery in the grip and lower power.