I recently purchased a WE 999c from the my local site, when purchased its FPS was reduced significantly from the WE standard, as to be within site regulations of <350 FPS. When chrono-ed however it was concernibly low at 250 FPS. I previously owned a King Arms Sig 556, which had its original spring removed after internals were replaced/upgraded. Testing this spring in the 999c resulted in a dramatically higher FPS of 380 FPS, so now I am firing too hot. Problem is that I have no idea what spring I am looking at getting, as the vendors of these AEGs are not open with the spring power inside. What spring power would be put into these AEGs, and which should I purchase to put it into a reasonable FPS of around 325?
Alongside this, I have found that the Spring Tension Release whenever putting the gun into safe keeps jamming the guns semi-auto mode. Half the time it triggers, the trigger just clicks and I have to move to full-auto to allow it to fire again, sometimes vice versa. The problem arises that in semi-auto sites I cannot go into full auto. Is there any way I can prevent this from locking up my gun every so often?
Any idea about any of these problems?