Sorry for bringing to life this old post...
I want to install on my KA Fn FAL a m110 spring and a inner barrel 6.02 to reach 420 FPS
Can somebody tell me if it is necessary to make some special modification on the gear box?
Somebody told me that I will need to change gears and piston because the m110 spring will break them.
Thanks for your time...
(Sorry for my english, I hope you can understand. The English it is not my mother leguage)