This is a truly unique example of the only known prototype/experimental Walther 9 mm Ultra pistol. The 9 mm Ultra Pistol and associated cartridges were developed on an experimental basis by Walther, for the Luftwaffe. The intent of this design was to manufacture a pistol that retained the compact aspects of the PPK/PP design but employed a far more powerful cartridge than the 9mm Kurz round but less powerful than the standard 9mm Parabellum cartridge. It is estimated that approximately 25,000 rounds of this unique 9 mm Ultra ammunition were ever manufactured by Gustav Genschow & Co. in the early 1940s with most of the ammunition either used during testing or destroyed after WWII. A very similar cartridge, albeit shorten and slightly less powerful, the “9mm Police” was introduced in the 1980s by Walther for the Walther PP Police pistol, but it never caught on. The development of this pistol was based on the proven Walther PPK/PP design however it employed several new and unique aspects only found on this exact pistol; the first being the innovative, sliding and rotating barrel that used side-mounted locking lugs. Traditionally the Walther PPK/PP pistol employed a blow-back designed recoil mechanism, however due to the higher velocity and pressure of this round it required actual locking lugs on the sides of barrel. These locking lugs mated with a corresponding internal raceway/locking recesses inside the slide. These internal slide raceways necessitated a shortened slide, as shown, which also resulted in a different barrel configuration, since the front sight had to be mounted on the barrel. The other unique aspect of this one of a kind pistol is that there is a spring loaded, slide accelerator mounted on the left side of the frame under the grip panel. This was required since the slide was shortened, that reduced the mass of the slide which requires the accelerator to drive the slide forward, rotating the barrel into the forward position and locking it in place, very innovative for a late 1939/40 designed pistol. The barrel configuration now resembles a P38 design. The pistol still ejects to the right, however the takedown procedure is different as there is a cross-pin threw the frame which holds the trigger guard in place. These mechanical features were revolutionary and set it apart from any previous Walther design even today. The grips are two-piece walnut with vertical grooves. The pistol has no visible markings, including no serial number. The pistol is finished in high polish blue with the sides of the frame polished bright. The magazine is blue and also unmarked. This pistol is pictured and discussed on page 106 of "Walther Volume III" by James L. Rankin, and pictured on page 212 of "The P.38 Pistol, Volume III" by Warren Buxton and page 143 of "Walther The Deutsche Legend" by Manfred Kersten. As noted this is the only one known example of this unique and historically innovative Walther pistols.

Very fine with most of the original blue finish remaining overall with minimal wear on the barrel, trigger guard and slide. The sides of the frame are still in the “white” as left after machining by the Walther factory. The grip straps are thinning and show a dull appearance. The grips are also very fine showing some moderate handling wear. The magazine retains 85% original blue finish showing normal wear from taking it in and out of the pistol. The bore is excellent. This unique experimental Walther and would be the center piece of the most advanced WWII or automatic pistol collection.