By the time the Nazis came to power the German P.08 Parabellum Luger was an outdated design and costly to manufacture. During their rearmament efforts the Germans asked pistol manufacturers to design a pistol that was inexpensive and simple to manufacture. Carl Walther Waffenfabrik had a definitive leg up on the competition as they had already been designing a new pistol: the AP (Armee Pistole). In 1938, after modifications the German Army adopted the new design as "Pistole 38". The new pistol was designed to shoot the 9mm Parabellum cartridge.
The Walther P.38 was ahead of its time and set the base line for the future of modern combat pistol design. The P.38 offered many innovative features such as a double action trigger (the first double action semi-automatic pistol used in military service), a simple and effective breech locking system (that is still employed today in modern combat pistols) as well as a loaded chamber indicator at the rear side of the slide, just behind the rear sight. To attest to the longevity of the design, in 1957 the new Bundeswehr, the West German Army adopted a modified version of the P.38 with an aluminum frame, dubbed the P.01 (Pistole 1). The U.S. Service pistol, the M9 and the commercial Berretta FS 92, both have many of the same design features found on the original P.38.
