[cocojo]

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?

 

[NM_P99]

The factory sights are especially sloppy in their fit to the slide, get some Meprolight night sights, they fit much tighter.
I too launched the plunger and spring across the room while I was messing with my P99, luckily I found everything.

 

[kdmoore]

I did the same thing with my mepro's

I purchased my p99 used, with mepros. My detent didn't slide freely afterwards and I think that it stuck momentarily in the lower position allowing the free slide of the rear sight. Then it launched.

I used a touch of light sanding on the detent, and I didn't have a problem adjusting it next range session.