I did what you said. After taking off the hex screw and taking off the switch, there is no spring and ball bearing underneath it. I do see the 3 little holes there. I bought the gun used and it came like that. I guess what I need is to look for a place that sells the ball bearing and the spring. Any suggestion as to where I can find them?
I may end up buying the whole selector switch set, sold at evike for $16. In the picture below, I see the spring, but not the bearing. Unless that yellow piece there is the ball bearing?