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BlowBack
Blowback is a system used in airsoft and gas-powered guns that moves the slide back and forth to simulate the recoil of a real firearm. After firing, gas (CO2 or Green Gas) pushes the slide rearward, and a spring returns it forward, readying the gun for the next shot. Blowback adds realism to shooting but also increases gas consumption.
What is blowback
When you pull the trigger, gas first propels the BB down the barrel. At the same time, part of the gas flows into the space above the slide. Gas pressure pushes the slide rearward – creating a recoil kick similar to a real firearm. A return spring then drives the slide forward again. In gas pistols, this cycle repeats with every shot. The slide movement uses extra gas because gas escapes along the sides of the slide during travel.
GBB vs NBB
| Feature | GBB (Gas Blowback) | NBB (Non-Blowback) |
|---|---|---|
| Realism | High (moving slide, recoil) | Low (slide does not move) |
| Gas consumption | Higher (gas powers both BB and slide) | Lower (gas powers the BB only) |
| Accuracy | Lower (slide movement affects aim) | Higher (fewer moving parts) |
| Noise level | Higher (slide impact) | Lower (quiet shot) |
| Price | Higher | Lower |
| Maintenance | More demanding (more moving parts) | Simpler |
Types of blowback systems
GBB (Gas Blowback) – the most common type found in airsoft pistols. Gas drives both the projectile and the slide. It delivers realistic recoil and a slide lock-back feature when the magazine is empty. Requires regular lubrication and seal cleaning.
NBB (Non-Blowback) – gas only drives the projectile; the slide stays fixed. The gun is quieter, more accurate, and uses less gas. A good pick for shooters who prefer function over realism.
EBB (Electric Blowback) – an electric motor in AEG guns moves a mock bolt or slide. The recoil effect is minimal and serves only as a visual feature. It does not affect gun function or accuracy.
Related terms: GBB, NBB, semi-auto, green gas, CO2