The Walther P38 (also known as a Pistole 38) is a 9 mm semi-automatic pistol that was developed by Walther arms as the service pistol of the Wehrmacht shortly before World War II. It was intended to replace the costly Luger P08, the production of which was scheduled to end in 1942.
The first designs submitted to the Heer (German Army) featured a locked breech and a hidden hammer, but the Heer requested that it be redesigned with an external hammer.
The final developmental stage in the P38's design history was the Modell MP/H (indicating exposed hammer). Apparently only a few were produced before the army adopted the HP in 1938 (Modell Heeres Pistole—Model Army Pistol). The production relationship between the HP and the almost simultaneous P38 (Pistole 1938) is unclear and quite confused.
The P38 concept was accepted by the German military in 1938 but production of actual prototype ("Test") pistols did not begin until late 1939. Walther began manufacture at their plant in Zella-Mehlis and produced three series of "Test" pistols, designated by a "0" prefix to the serial number. The third series pistols satisfactorily solved the previous problems for the Heer and mass production began in mid-1940.