Upgrades to SA H02

[Jo1906]

Hey

 so I’ve got this thing , (a knock off hk 416) and I’d like to make it better in every way.

it’s got a gate aster already, so what decent internal gubbins can i buy to improve the range, rate of fire and reliability without rinsing my bank?

i’ve also got an umarex glock 17, so same question as above  

thanks

alex View attachment 115628