World War II
The impetus for the development of the PPSh came partly from the Winter War against Finland, where the Finnish Army employed the Suomi KP/-31 submachine gun as a highly effective tool for close-quarter fighting in forests and built-up urban areas.
Although the PPD-40 was rushed into mass production in 1940, it was expensive to manufacture, both in terms of materials and labor, because it used numerous milled metal parts, particularly its receiver. Shpagin's main idea for cost reduction was to use metal stamping for the production of most parts; that concept was revolutionary in the Soviet Union at the time. Shpagin created a prototype in September 1940, which also featured a simple gas compensator designed to prevent the muzzle from rising during bursts; this improved shot grouping by about 70% relative to the PPD.
The new weapon was produced in a network of factories in Moscow, with high-level local party members made directly responsible for meeting production targets. A few hundred weapons were produced in November 1941 and another 155,000 were made during the next five months. By spring 1942, the PPSh factories were producing roughly 3,000 units a day. Soviet production figures for 1942 indicate that almost 1.5 million units were produced. The PPSh-41 is a classic example of a design adapted for mass production (other examples of such wartime design are the M3 submachine gun, MP40, PPS, and the Sten). Its parts (excluding the barrel) could be produced by a relatively unskilled workforce with simple equipment available in an auto repair garage or tin shop, freeing more skilled workers for other tasks. The PPSh-41 uses 87 components compared to 95 for the PPD-40 and the PPSh could be manufactured with an estimated 5.6 machining hours (later revised to 7.3 hours) compared with 13.7 hours for the PPD. Barrel production was often simplified by using barrels for the 7.62mm M1891 Mosin–Nagant rifle: the rifle barrel was cut in half and two PPSh barrels were made from it after machining the chamber for the 7.62mm Soviet submachine gun cartridge.
After the German Army captured large numbers of the PPSh-41 during World War II, a program was instituted to convert the weapon to the standard German submachine gun cartridge – 9mm parabellum. The Wehrmacht officially adopted the converted PPSh-41 as the "MP41(r)"; unconverted PPSh-41s were designated "MP717(r)" and supplied with 7.63×25mm Mauser ammunition (which is dimensionally identical to 7.62×25mm, but slightly less powerful). German-language manuals for the use of captured PPShs were printed and distributed in the Wehrmacht.
The PPSh-41 suffered from problems with its unreliable drum magazine. Initially made of stamped metal only 0.5 mm thick it was prone to deformation leading to jams. It was also relatively expensive to produce and fairly slow to fill. It was mostly superseded by a simpler box-type magazine holding only 35 rounds, although an improved drum magazine made from 1 mm thick steel was also introduced in 1944.
The PPS, an even simpler submachine gun, was later introduced in Soviet service in 1943, although it did not replace the PPSh-41 during the war.
The Soviet Union also experimented with the PPSh-41 in a close air support anti-personnel role, mounting dozens of the submachine guns in forward fuselage racks on the Tu-2sh variant of the Tupolev Tu-2 bomber.
More than five million PPSh submachine guns were produced by the end of the war. The Soviets would often equip platoons and sometimes entire companies with the weapon, giving them excellent short-range firepower. Thousands more were dropped behind enemy lines in order to equip partisan formations to disrupt German supply lines and communications.
After the Second World War, the PPSh was supplied in large quantities to Soviet client states and Communist guerrilla forces. The Korean People's Army (KPA) and the Chinese People's Volunteer Army (PVA) fighting in Korea received massive numbers of the PPSh-41, in addition to the North Korean Type 49 and the Chinese Type 50, which were licensed copies of the PPSh-41 with small mechanical revisions. The weapon was widely used during the Korean War.
Though relatively inaccurate, the Chinese PPSh has a high rate of fire and was well-suited to the close-range firefights that typically occurred in that conflict, especially at night. United Nations forces in defensive outposts or on patrol often had trouble returning a sufficient volume of fire when attacked by companies of infantry armed with the PPSh. Some U.S. infantry officers ranked the PPSh as the best combat weapon of the war: while lacking the accuracy of the U.S. M1 Garand and M1 carbine, it provided more firepower at short distances. As infantry Captain (later General) Hal Moore, stated: "on full automatic it sprayed a lot of bullets and most of the killing in Korea was done at very close ranges and it was done quickly – a matter of who responded faster. In situations like that it outclassed and outgunned what we had. A close-in patrol fight was over very quickly and usually we lost because of it." Other U.S. servicemen, however, felt that their M2 carbines were superior to the PPSh-41 at the typical engagement range of 100–150 meters.