TM 416 NGRS - Retro arms Gearbox install 

Interesting. Fitted a few of these gearboxes myself (2x MK18 and a 416) and I do think they are superb. Always pressed in FLT 8mm bushings before fitting and only issues I have had are with trigger pin hole needing the anodising removed for easy pin insertion. Not had a hop issue so more likely a slight variation in the unit I would guess? The thing that grabs you is just how light weight they are and you can see and feel that they are much stronger than the original.

What gears you used? Also, any suggestion how to fix a wobbly bushing?

What grip do you have on?

영상 감사합니다. 한국에서는 200불 넘던데, 무튼 구입해서 교환해야겠네요. 하나 둘 바꾸면서 정체성이 없어지는 것 같네요 ㅋㅋㅋ

I need a new shell mate where did u get yours from?