This is my first Ever build MK V2 in the HK416.
Shs cylinder and cylinder head (one Piece)
Shs gears… 18:1
Wells spring retainer
Gen 9 Trigger
Cut the spring retainer bolt as it was too long.
Cut the spring on top of the motor axle shaft
To allow pinion gear to Beville gear meshing at 100%
Shaved the top of the trigger mechanism to allow a snug fit in the gearbox
Trimmed about a millimetre off the cylinder to allow it to fit in the gearbox.
As I said this is my first ever build, the MK V2 gearbox Drop straight in to the HK receiver with zero modifications, fits beautifully.
The whole thing was very easy, even for a beginner like myself.