Airsoftpedia Hop-up and accuracy
How to choose the right barrel for your airsoft gun
The inner barrel in your airsoft gun plays a key role in accuracy and range. Choosing the right barrel improves the stability and trajectory of the BB. Here is what you need to know when choosing a barrel.
Find the right length
A new inner barrel almost always needs to be the same length as the original. Measure your old barrel if you are unsure. Manufacturers sometimes differ by a millimetre or two.
AEG
Most AEGs use a standard hop-up (Tokyo Marui style), so length is what matters most. The barrel has to fit inside the outer barrel. A slightly longer barrel can sometimes be used if it ends inside the flash hider.
| Length | Typically fits |
|---|---|
| 229 mm | Tokyo Marui MP5A4/A5, AK-47 Beta Spetsnaz |
| 247 mm | G36C, P90, SG552 |
| 275–280 mm | AKS-74U |
| 285 mm | M4 CQB-R / Mk18 (10.5") |
| 300 mm | M4 with 11.5" outer barrel, Thompson |
| 363 mm | M4A1 Carbine (14.5"), SG551, M249 Para |
| 407 mm | M4 with 16" outer barrel (SPR length) |
| 455 mm | AK-47 and AK-74M |
| 509–510 mm | M16 (20"), AUG standard |
Sniper rifles
Many sniper rifles are based on the VSR-10 system and share barrels and hop-up. VSR-10 compatible barrels typically also fit the Action Army AAC T10, Ares Amoeba Striker and ASG Steyr Scout. The L96 and MB series, SR-2 and Silverback SRS use their own systems.
| Length | Typically fits |
|---|---|
| 303 mm | Tokyo Marui VSR-10 G-Spec |
| 430 mm | Tokyo Marui VSR-10 Pro Sniper, Action Army AAC T10, Novritsch SSG10 |
| 448 mm | Maruzen APS SR-2 |
| 500 mm | Tokyo Marui L96 AWS, Well MB01, MB04 and MB4401 |
| 550 mm | Ares Amoeba Striker AS01 |
| 578 mm | Silverback SRS A1 22" (uses AEG barrels) |
Gas and CO2 pistols
For gas pistols, CO2 blowback pistols and GBB rifles we have a separate guide with lengths for Glock, Hi-Capa, M1911, AAP-01 and more: Inner barrels and hop-up buckings for gas pistols (GBB).
Bore: what do 6.01, 6.03 and 6.08 mm mean?
- Precision barrels (6.01–6.03 mm): Less air escapes past the BB, giving more stable shots and better accuracy. The barrel must be kept clean to avoid jams.
- Standard barrels (typically 6.08 mm or wider): Less sensitive to dirt and need less maintenance, but give lower accuracy than a precision barrel.
- Fluted barrel: Designed to save weight and give a distinctive look. Mainly a cosmetic upgrade with no significant effect on performance.
Myth: A longer barrel does not always mean better accuracy. The hop-up system plays an equally important role, and a barrel that is too long can actually give worse results if the air volume does not match the barrel.
Choice of material
- Brass: Common and inexpensive, but needs frequent cleaning to maintain performance.
- Aluminium: Light and durable, but can be less accurate than steel.
- Stainless steel: Very durable and accurate, but also more expensive.
How to change the barrel
- Remove the hop-up unit from the old barrel.
- Clean the new barrel thoroughly before fitting.
- Fit the new barrel in the hop-up unit and make sure it is seated correctly.
- Reassemble the gun and adjust the hop-up until the BBs fly straight.
When should you upgrade?
If you experience inaccurate shots, want longer range, or want to specialise your gun as a sniper rifle or DMR, a new barrel is a good investment. Find barrels for AEGs, sniper rifles and gas and CO2 pistols.
