(an ongoing compilation from anyone willing to share)
The Walther P99 (and it's S&W counterpart) are truly fine pistols, but they have one major weak link. "Civilian Legal" full capacity mags are annoyingly expensive - if you can even find them. Since I've recently decided to move from Glocks to Walthers, I have some incentive to find a way to feed this pistol without going broke on mags.
At the moment I only have some preliminary experiments done by others. In the near future I will be doing my own experiments and posting the results. (I'll also take any submissions from other experimenters)
Update: There's a new page showing how some of the common double-stack mags fit in the Walther P99 frame.
Update: There are some pre-ban P99 mags floating around. What I've found on Factory Hi-Caps
Jim shows us some of his attempts at converting mags and some measurements: Jim's pics & narrative
If you know of another magazine type that I haven't mentioned that might fit or have pictures/info to share on mags that do fit, drop me a line at Cranky@CrankyLabs.com