Founded in 1886, the Carl Walther GmbH concern designed and manufactured many small arms prior to World War 2 (1939-1945). In 1929, the Walther PP compact semi-automatic pistol was unveiled, its target customer being primarily police units and, to an extent, paramilitary type units requiring use of a highly portable, holstered weapon (indeed, the "PP" designation stood for "Polizei Pistole", translating to "Police Pistol"). In the end, the weapon found considerable use across both military and civilian markets and proved one of the most famous of its kind - really the first truly successful double-action semi-automatic pistol using an external hammer. The PP line was broadened with the introduction of the more compact Walther PPK in 1931 (detailed elsewhere on this site). The PPK was the sidearm of choice for fictional spy hero James Bond and was used by Adolph Hitler to commit suicide at the end of World War 2. Over 5 million Walther PP/PPK pistols were eventually produced with manufacture still ongoing today (2013).
The PP was a clean and handy pistol design utilizing the basic accepted form as semi-automatic handguns go. The design consisted of a metal slide covering the barrel, internals and recoil spring. The magazine was inserted into the integrated pistol grip in the usual way, the cartridges managed by a simple spring mounted in the magazine's design. The trigger sat within an oblong trigger ring and used to manage the action. A tang ensured a proper feel in the primary hand while the hammer lay exposed at the upper rear of the receiver. The PP utilized fixed iron sights for accuracy - a rear notch system aligned with a front blade, the sights being fitted over the slide in the usual way. The safety lever was set to the left side of the slide with the ejection port over the right side.
The pistol was originally chambered for the 7.65x17mm Browning SR (.32 ACP) cartridge but the line eventually grew to include 9x17mm Short (.380 ACP), .22 Long Rifle, 6.35x15mm Browning SR (.25 ACP) and 9x18mm Ultra (PP-Super) forms. In its 7.65mm chambering, the handgun was allowed eight cartridges from its single-column magazine. Magazine extensions proved popular which increased the surface area at the palm/finger grip when handling the pistol. A barrel extension could be added at the muzzle to increase accuracy to an extent though at the cost of compactness.
The PP utilized a basic "straight blowback" system of operation. Several safety features were incorporated into its design including a "signal pin" above the hammer used to visibly identify a loaded cartridge in the chamber (this safety featured was accordingly dropped during World War 2 wartime production for expediency). Another safety feature employed was a slide-mounted safety catch which forced a long trigger pull to ensure a deliberate action was required. As such, the PP could be carried, loaded and ready to fire, in relative safety by the operator - a strong quality for security- and military-minded personnel requiring fast reaction times.
During World War 2, the PP went on to see issuance to German civilian and military police and various military branches including the Luftwaffe, staff officers and Panzer tank crews. They proved reliable in service and valued for their portability in-the-field. Wartime variants were also produced with poorer finishes to help fulfill the expansive military demand. Manufacture of the PP continued throughout the war and beyond it, seeing licensed (and some unlicensed) production around the globe.