jg hk416 gearbox downgrade/upgrade

[neverseemecoming]

hi all. i have a jg hk416 and have decided its time to get the gearbox sorted by slowing the fps and raising the rof.
at the moment the poor mans chrono is telling me its firing at 385 or above. but i dont think by far.

my main question is what spring do people think i should use to take the fps down to the urban limit. i havent replaced a spring before so i have no idea of how major the differences are and what all the m ratings such as m90, m100 or 1 joule mean tbh. it has the standard spring obviously at the moment and a mad bull tightbore if that helps at all ???

i also need metal bushings at least but i was hoping it would fall into one of zero ones full tune up kits to save money and give me some nice extras too :-)

any help is greatly appreciated

[danhc]

Re: jg hk416 gearbox downgrade/upgrade

systema metal bushings, m100 spring, modify gearset and systema turbo motor and not to forget max a decent battery