FB 3.0s Titan enhanced gearbox into HK416v3

Hi everyone,

I’m about to drop the Fighting Brothers 3.0s Titan enhanced edition into my LDT HK416v3. As far as im aware, there isnt much to be done apart from:

  • Using existing t-piece and barrel from hk
  • installing new metal pinion gear on stock motor.
  • checking shimming although i believe its pre shimmed.

Is there anything else that i need to consider?


I just bought one of these.
You WILL need to shim it. Mine was very loose.
I also found, for some reason the ladder gear on the piston stripped real quick, and didn’t seem to engage very well with the sector gear. Almost like they were too short.

To be honest I thought having a split gearbox would be handy, but I’ve found it a bit of a pain. Easily comes apart when trying to install into the receiver I have.

You might want a new spring retainer bolt too. Its a rubbish plastic one as standard.