Airsoft Inner Barrel Finder
An inner barrel fits only when two things match: the hop-up cut (which standard your gun uses) and the length in millimetres (set by your outer barrel or slide). Match your gun to one of the four standards below, find the correct length for your exact platform, then compare every compatible inner barrel we track with prices across retailers. We cover 5,637 inner barrels across AEGs, gas pistols, VSR snipers and gas rifles.
AEG Inner Barrels
AEG inner barrels use the longer, bridged AEG hop-up window and fit the standard electric gun hop-up unit shared by almost every Tokyo Marui-compatible AEG: M4 / AR, AK, MP5, G36, SCAR, P90 and more. The catch is length: an AEG barrel only fits if it also matches the length your gun needs, which is set by the outer barrel. Brands like Prometheus, Maple Leaf, Madbull, Lambda, PDI and Modify all build AEG-cut barrels in a full range of lengths, so match the cut first and then the length for your platform.
Gas Pistol (GBB) Inner Barrels
Gas blowback pistols use the shorter GBB / pistol hop-up cut with an open window. Fitment here is driven mostly by length, which is set by the slide and outer barrel of the specific model: a Hi-Capa 5.1, a Glock 17 and a Glock 19 all need different lengths. The window cut is shared with VSR snipers, but the barrels are NOT interchangeable with them because the external retaining-notch positions and lengths differ. Manufacturer also matters: a Tokyo Marui-spec barrel window can differ from a VFC or KWA one at the same length, so match the length AND the maker.
VSR-10 & Bolt-Action Sniper Inner Barrels
The Tokyo Marui VSR-10 is the airsoft bolt-action barrel standard, shared across the VSR-compatible ecosystem: JG BAR-10, Well MB series, CYMA, Maple Leaf, Novritsch SSG10 / SSG24 and more. VSR barrels use the open window cut but, unlike buckings, are NOT interchangeable with gas pistol barrels because the retaining notches and lengths differ. Snipers are precision builds, so length is chosen to balance the cylinder volume and BB weight rather than just to fill the outer barrel: 430mm is the common VSR length, while the larger L96 / APS2 cylinder suits longer barrels.
Gas Blowback Rifle (GBBR) Inner Barrels
Gas blowback rifle barrels use a GBB-style cut but are strongly platform-specific: the Tokyo Marui MWS, WE, GHK and VFC systems each differ in length and mounting, so there is no single GBBR interchange pool. Most M4-pattern GBBRs (TM MWS, WE, GHK) run around 370mm, while shorter carbines and longer rifles vary widely. Always identify your exact system before buying, and match the barrel to that platform rather than to another gas rifle.
What inner barrel fits my gun?
| Your gun | Barrel standard |
|---|---|
| M4 / AR-15, AK, MP5, G36, SCAR, P90 AEG (electric) | AEG |
| Systema PTW / Tokyo Marui Next-Gen | AEG |
| Hi-Capa, 1911, Glock, M9 gas pistol (GBB) | Gas Pistol |
| AAP-01 gas pistol | Gas Pistol |
| VSR-10, BAR-10, Well MB spring sniper | VSR / Sniper |
| Novritsch SSG10 / SSG24 | VSR / Sniper |
| L96 / APS2 spring sniper | VSR / Sniper |
| TM MWS, WE, GHK, VFC gas blowback rifle (GBBR) | GBBR |
| GBB SMG (gas) | GBBR |
Tap a standard to see compatible inner barrels and the length table. Rotate your phone for fitment notes.
Why length matters as much as the cut
The hop-up cut decides whether a barrel physically seats in your hop unit, but the length decides whether it fits your gun. Length is set by your outer barrel or slide, not by the cut. A barrel that is too long protrudes past the outer barrel and needs a mock suppressor or extension, while one that is too short leaves the hop unit unsupported. Each standard page below carries a length-by-gun table so you can read the correct length for your exact platform. On AEGs and snipers, also balance the length with your cylinder volume: a long barrel with a stock or ported cylinder can under-volume and lose consistency.
Which bore (6.01 to 6.05) do I need?
Bore is the inner diameter of the barrel and it is a performance choice, not a fitment one. Any bore in the right cut and length will fit your gun. A tighter bore trades reliability for a small consistency and FPS gain, while a wider bore trades that back for feed reliability and heavy-BB tolerance. Match the bore to your BB quality and how you actually play.
| Bore | Character |
|---|---|
| 6.01 to 6.02 | Tightest |
| 6.03 | All-round sweet spot |
| 6.04 | Forgiving |
| 6.05 and wider | Most reliable |
Frequently asked questions
How do I know which inner barrel fits my gun?
Two things must match. First the hop-up cut: AEGs use the longer AEG cut, while gas pistols, VSR snipers and gas rifles use shorter open-window cuts. Second the length in millimetres, which is set by your gun's outer barrel or slide. Match your gun to one of the four standards below, then use its length table to find the correct length for your exact platform.
Is inner barrel length the same as fitment?
Length is half of it. A barrel of the right cut still only works at the right length: too long and it protrudes past the outer barrel, too short and the hop unit is unsupported. Always match both the cut (the standard) and the length (from the table on each page) for your specific gun.
What bore (6.01 to 6.05) should I run?
Bore is a performance choice, not a fitment one. A tighter bore (6.01 to 6.03) can raise consistency and FPS slightly but needs clean BBs and a good air seal. A wider bore (6.04 to 6.05) is more forgiving and reliable. For most players a 6.03 is the sweet spot, while high-volume skirmishers often prefer 6.05.
Are outer barrels covered here?
No. This finder covers inner barrels only. Outer-barrel fitment depends on thread pitch, gas block and model-specific mounting, so it does not form clean interchange sets the way inner barrels do. We focus on inner barrels where honest, reliable fitment groups exist.
Looking for something specific? Search all inner barrels or browse the full parts catalog.