Hi Jim,
I have the same problem with the set screws for the gears on my 8 x 20, and have yet to resolve the situation. I tried flattening side of the brass rod that the gears go on with a file - it does help some, but they still seem to work their way loose. I think the drilling a small hole is about the only way to go. I have thought about using some glue or Lock-tight in the set screw hole once it's tight, but that would make it more or less permanent.
For what it's worth, even with the set screw loose, the front geared standard is still pretty firm on my front gear rails and it doesn't seem to make much difference in making the exposure.
Dan