Just wanted to give a head's up. I just bought some P99 .40S&W mags, they have the same measurements, they do not rattle, the magazine catch works properly, slide locks back properly, but the feed lips are approximately 1/32" wider than the 9mm, so the cartridges just pop right back out.
Patent # 5,386,657 same as the body for the PPQ 9mm mags