If you remove the cylinder latch screw, it can have a tendency to walk out from then on unless you loctite it or stake it. There's really not a good reason to ever remove the screw in the first place, so that's probably not much of an issue.
I guess the grip screw could get loose, but that's something you'd probably notice.
They're pretty solid. Short of abuse, I doubt you'd ever wear one out by shooting it.