A friend of mine got interested in Airsoft and had made his mind up that the HK417D would be a nice platform to start from. Well, turned out one of our teammates had one for sale. The biggest problem was that it had been run with HPA, meaning the gearbox shell is completely empty and no parts where available.
I sorted through my spareparts and got all the parts needed to get it working again. The idea was to get it made cheap but still well working, as it’s still a first replica for my friend. The other thing is upgradability on the replica, since the gearbox is a V 2.2 so to say… It has both V2 and V3 parts inside, but still has some parts proprietary. For example, the ARL seems to be proprietary, I had to cut one of the arms a bit for it to fit, and still have flex enough actually to work.
According to the friend to whom this project is, there is actually a conversion kit that presumably converts it to a more “standard” gearbox. So, there is a chance I’ll revisit this build very soon.
The final product looks good, has a nice trigger response due to fast 13:1 gears (SA). There is no mosfet so its a very basic build otherwise.
Lower and Gearbox 
Gearbox empty 
Gearbox 
Final product 
Final product