Check this for more info:
http://thefiringline.com/forums/showthread.php?t=434259
Notes:
1. The slide stop plunger does NOT retain the slide stop; the slide itself should do that, allowing the slide stop to be taken out at only one place. If the gun depends on the slide stop plunger to retain the slide stop, or if you have had to cut a notch or groove in the slide stop to keep it from drifting out, your gun was not made properly.
2. The safety catch plunger does NOT retain the safety catch. The catch is retained by its interior lug interfacing with the sides of the hole in the frame. To try this, take out the safety and remove the plunger entirely, then put the safety back in. It should not be able to be inserted or removed except at one point between safe and fire; if it can be removed in either the up or down position, the gun is defective.
Jim