install a m120 spring
 

i have a M4 HK18 full metal, and i just bought a M120 spring for it, i need someone that i can send it to that knows how to install one

I'm not familiar with the K18 but I have notice that many of the newer M4s are now coming with what is called upgraded internals included M120 springs. to name some; Echo1 Platinum Edition M4, VFC MLL M4s, JG, Etc.

I feel like spoon feeding :P

http://www.airsoftcanada.com/showthread.php?t=72809

yeah mine has a low power spring for indoor, but im playing outside so i want it higher so i bought a m120 and i need it installed

does anyone know where there is a write up on these things? i want to put the original m120 back into my SRC M4 for the summer.
i want to learn how to do it, so i can put my s90 back in when i got some indoor games.

mechbox.com
http://www.mechbox.com/mechbox/v2-me...g-upgrade.html

thanks a lot man, i'm going to attempt this closer to the summer to get ready for the out doors season.

No worries man, hope it works out for you.