Not sure about the first two lines, but the lower line is Adliswil (town,) ZH (Zurich canton). I know the post is old, but in case you revisit it, does the rifle have a stamp in the stock that looks like a shield with letter(s) in it? It may confirm Zurich as the canton.
As an aside, if anyone ever gets the chance to go to Switzerland, I HIGHLY recommend it, although I don't know if it's safe anymore, what with their buckling to the Shengen crap to be invaded by third world.......future astrophysicists.