The Walther P38 (originally written Walther P.38) is a 9 mm semi-automatic pistol that was developed by Carl Walther GmbH as the service pistol of the Wehrmacht at the beginning of 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 German Army featured a locked breech and a hidden hammer, but the Heer (German Army) requested that it be redesigned with an external hammer.
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, using Walther’s military production identification code “480”. After a few thousand pistols the Heer changed all codes from numbers to letters and Walther was given the “ac” code.
Several experimental versions were later created in .45 ACP, and .38 Super, but these were never mass-produced. In addition to the 9×19mm Parabellum version, some 7.65×21mm Parabellum and some .22 Long Rifle versions were also manufactured and sold.
From an engineering perspective the P38 was a semi-automatic pistol design that introduced technical features that are found in other semi-automatic pistols like the Beretta 92 and its M9 sub-variant adopted by the United States military.
The P38 was the first locked-breech pistol to use a double-action/single-action (DA/SA) trigger (the earlier double-action PPK was an unlocked blowback design, but the more powerful 9×19mm Parabellum round used in the P38 mandated a locked breech design). The shooter could chamber a round, use the safety-decocking lever to safely lower the hammer without firing the round, and carry the weapon loaded. This lever can stay down, keeping the pistol “on safe” or be immediately returned to the straight position, keeping the weapon safely “ready” with a double-action trigger pull for the first shot. Pulling the trigger cocks the hammer before firing the first shot with double-action operation. The firing mechanism extracts and ejects the first spent round, cocks the hammer, and chambers a fresh round for single-action operation with each subsequent shot – all features found in many modern day handguns. Besides a DA/SA trigger design similar to that of the earlier Walther PPKs the P38 features a visible and tactile loaded chamber indicator in the form of a metal rod that protrudes out of the top rear end of the slide when a round is present in the chamber.