The SW99/P99 magazines offered at CDNN work well in the Smith version as well as the Walther P99 and are available for $12.99 to $19.99, depending on caliber and capacity. Here's a link:
A forum community dedicated to Walther firearm owners and enthusiasts. Come join the discussion about performance, gunsmithing, troubleshooting, reviews, accessories, classifieds, and more!