got a prowin 8mm box in my VFC HK416
ILLusion is right about it being a pain to install (was up till 5am).
now that i have it all set up and running smooth, it sure is one hell of a sweet gearbox.
there is still some tweaking i need to do but damn, can it ever spit out BBs.
400 round hicap emptied in about 10sec on 8.4v with the M80 spring.
the gears are really quiet, but the motor and antireverse latch make quite a racket.
im running a set of systema tourque-up helical gears.
next step, pinp it out with a crap load of usless accessories.