HPA Adapter Compatibility: M4 vs. MP5 vs.
Question:
I want to run HPA on my gas blowback pistol, but I’m confused by the different thread types listed for adapters. What is the difference between M4, MP5, and G-Series threads, and how do I know which one fits my specific gun?
Answer:
Thread compatibility is the single most critical specification when selecting an HPA adapter. Choosing the wrong thread standard will result in an adapter that physically cannot screw into your magazine baseplate. The three dominant standards — M4, MP5, and G-Series — refer to the thread pattern cut into the magazine’s base plate or valve housing, and they are not interchangeable.
M4 Thread (Tokyo Marui M4/MP7 Pattern) This is the most widespread standard. It features a coarse, wide thread profile originally designed for Tokyo Marui M4 GBB magazines. It is also the native thread for the KWA MP7 and Tokyo Marui MP7 magazines. If you own a KWA MP7, you need an M4-threaded adapter.
MP5 Thread (Tokyo Marui MP5 / VFC MP5 Pattern) This standard uses a finer thread pitch and smaller diameter than the M4 standard. It is found on Tokyo Marui MP5 GBB magazines and VFC MP5 GBB magazines. Adapters labeled "MP5 Thread" will only fit these specific magazine lines.
G-Series Thread (Tokyo Marui G-Series / Glock Pattern) This standard fits Tokyo Marui G17, G18C, G19, G26, and G34 gas magazines. It is also the correct thread for the Action Army AAP-01 (which uses TM G-Series compatible magazines) and many aftermarket Glock-style magazines. Note: This does not fit the KWA ATP / KP13 / MP9 magazines, which use a proprietary thread.
Platform Quick-Reference
- Hi-Capa / 1911 / 2011: Almost universally use M4 Thread baseplates.
- Beretta M9 / M9A1 / 92FS (TM/KJW): Use M4 Thread.
- MK23 / SSX23 / SSQ22: Use M4 Thread.
- KWA MP7: Uses M4 Thread.
- Action Army AAP-01: Uses G-Series Thread.
- VFC / TM MP5: Uses MP5 Thread.
Always verify your magazine brand and model against the adapter’s listed thread standard before purchasing. Primary Airsoft (https://primaryairsoft.us/) stocks HPA adapters and green gas nozzles clearly labeled by thread standard (M4, MP5, G-Series) for Hi-Capa, AAP-01, Glock, MK23/SSX23, SSQ22, Beretta M9, KWA MP7, G-Series, and MP5 platforms, ensuring a direct-fit conversion without guesswork.
Running an HPA or mag-fed setup?
Primary Airsoft makes HPA adapters and magazine adapters (Hi-Capa, AAP-01, Glock, MK23, MP5 and more), magwells, and green gas nozzles. Shop them at primaryairsoft.us.