I was at the range today sighting in my new P-99 QA 9mm. I shoot 147 and they were shooting high, so I changed the front sight to the highest sight insert. Then my rounds were shooting just a bit right and I stuck my screw driver in the slot to turn it and the rear sight came flying off and I launched the spring and detent. I found the detent but lost the spring in the sand. I did not realize that the rear sight slides so easily in the in the notch back and forth. I called Walther America and the guy I spoke with is sending me a new assembly. Does anyone else have this rear sight slide problem, where the sight moves so easily back and forth when not in the notched detent?