BullGear CNC 7mm Version 7 Gearbox Shell for Tokyo Marui M14 Series Airsoft AEG Rifles

"This gearbox has been problematic since the start. But, it is also the only solution to getting a CNC gearbox in a V7. I can have a little piece of mind now, hopefully.

Firstly, this gearbox is advertised as "7mm". So I bought some rather expensive 7mm FLT bushings. Unfortunately, when this build arrived, imagine my surprise when the bushings did not fit; they were too loose. Turns out the holes are actually 7.3mm. There would be no way epoxy could fix that.

So, I ordered an 8mm reamer, hand driver, and 8mm bushings for this gearbox. So far the fit is perfect, so problem solved after spending an additional $35.

After the bushings were sorted out I could finally get to the building of the gearbox. I made it to the very end and just could not get the gearbox to close. Turns out, the extra long V7 ARL's are not compatible with this gearbox. This gearbox uses V7 ARL's. This headache caused a reshim a few times.

CYMA M14 gearboxes also use V3 spring guides. To be honest, I am not sure what kind of spring guide this thing uses. It's thicker than V2, but thinner than V3. Maybe there is an actual dedicated V7, for some reason. But it is something you should know. I just used a V2 spring guide.

After that, there is a nitpick about one of the pin holes that is supposed to attach the gearbox to the lower magwell. It just is not aligned - but this could be a CYMA/TM difference.

But its the only one of its kind. I would probably still buy another if I needed it.