Captain Jack (Updated: 4/29/2013):
It was about the middle of the 1920s that Soviet engineers began development of various indigenous submachine gun types. Despite a few end-products appearing, none were produced nor used on a large scale. In 1934, Soviet gunsmith Vasily Degtyayrov (1880-1949) began work on another inspiring Soviet submachine gun design, this endeavor no doubt influenced by the preceding German Bergmann MP18 of 1918 (MP18 = "Machine Pistol 1918") - the world's first true submachine gun.
The MP18 itself was born through work initiated by Hugo Schmeisser in 1916 through the Bergmann Waffenfabrik works for the Imperial German Army. The weapon made it to the front lines of World War 1 in the hands of special German trench-clearing units and stayed in production after the war despite the restrictions of the Treaty of Versailles. Since the original design was made for full-automatic fire only, a revision in 1928 introduced selective fire which begat the MP28/2 mark - allowing for single- and full-automatic shooting. The type proved excellent enough to still be in play by the time of World War 2 (1939-1945) for even the British copied the design outright when shortages of capable homegrown submachine guns was apparent and the threat of war in Europe became a realization.
For the Soviets, their own 1934 initiative produced the unimaginative PPD series submachine gun ("PPD" = "Pistolet-Pulemyot Degtyaryov") (translating to "Pistol, Machine, Degtyaryov"). The system was chambered around the 7.62x25mm Tokarev Soviet pistol round which, despite its light weight, gave it performance comparable to that of the German 9x19mm Parabellum due to the increased muzzle velocity. The action centered around a blowback system of operation utilizing an open bolt design and the gun was developed as a selective-fire weapon from the beginning (unlike the MP18). The operator managed a cocking handle set to the right of the receiver in the usual way, an oblong ejection port situated along the top-right side of the receiver ejecting spent casings. The receiver, barrel and all applicable metal-works were saddled within a short, single-piece wooden body which made up gun's forend/forward hand grip, pistol grip and shoulder stock. The curved trigger unit sat below the wooden section within an oblong trigger guard in the normal fashion - this assembly fitted just ahead of the integrated pistol grip. The top face of the weapon was decidedly rounded in its appearance with an iron sight fitted over the receiver and another at the muzzle to facilitate ranged fire. The barrel assembly was completely shrouded within a perforated metal jacket sporting elongated slots for heat dissipation while serving to protect the operator's support hand in the event of accidental contact. Like the MP18/MP28 before it, the PPD was fed from a drum magazine - the first Soviet weapon to feature this mechanism. Each drum held up to 71 x 7.62mm cartridges which provided the Soviet infantryman with a deep ammunition supply at the expense of it being cumbersome and adding weight. The drum magazine could be replaced with a more manageable 25-round curved detachable bow magazine if need be. Magazines were inserted into the bottom of the wooden body through an awaiting well.
All told, the weapon weighed 3.2 kilograms sans its magazine and sported a running length of 788mm with a barrel length of 273mm. Rate-of-fire was listed at 800 to 1000 rounds per minute which gave the operator a good deal of suppression firepower. Muzzle velocity was rated at 1,600 feet per second which, coupled with pistol cartridge, restricted the weapon for primary use at short-to-medium engagement ranges. Effective range was roughly 200 meters (approx. 650 feet).
One of the noticeable elements of the PPD's construction was its high quality internally, an all-steel approach with no steel stampings being used. Additionally, both the chamber and bore were chrome-lined (popular with Soviet guns) which increased the life of the weapon considerably, even with poor maintenance and general abuse. Of course in peacetime years, such quality was understood and acceptable though, once in wartime, this proved another matter entirely.
Initial PPD guns were designated as "PPD Model 34" (or "PPD-34") and entered service with Soviet elements in 1935. The weapon was primarily issued to Communist police forces and border elements and was limited by high per-unit procurement costs and manufacturing complexities. Some did see use in the Spanish Civil War (1936-1939) after 1937. In 1938, an attempt by Degtyaryov to simplify his weapon produced the "PPD-34/38" designation. The barrel jacket cooling slots were revised into a simpler formed shape and other, more subtle, changes were implemented.
In 1940, after practical use of the weapon in-the-field allowed, yet another attempt was made to simplify the weapon for manufacture and this returned the "PPD-40" model. The original Soviet-designed drum magazine and feed was replaced with a style patterned after the Finnish Suomi Submachine Gun. The Red Army faced the capable Suomi throughout the 1939-1940 "Winter War" against their determined neighbors and developed an appreciation for its simpler mechanism thanks to captured samples being acquired in-the-field. The modification to the Soviet guns forced the single-piece wooden body to become two with a notch now formed under the gun to accept the new drum magazine. The drum was inserted via a side motion ala the American Thompson Submachine Gun ("Tommy Gun").
All production on PPD submachine guns eventually ceased in 1941 to which related factories eventually fell under the weight of German conquest after the brazen invasion of the Soviet Union through "Operation Barbarossa" in June of 1941. The loss of PPD factories was a blow to Soviet forces to be sure for now they faced with massive shortages of all sorts of weaponry. Whole factories were completely relocated east of the Urals and began rigorous production of war goods through nonstop work. What PPD weapons did not fall into enemy hands during the invasion pressed on in service until their usable service lives had expired. Eventually, the PPD was replaced by more effective - and cheaper - Soviet submachine guns beginning to come online such as the "PPSh-41" of 1941. It was the PPSh-41 that went on to become the iconic Red Army submachine gun of World War 2.
As many as 90,000 PPD submachine guns may have been produced during the span of 1934 to 1941. It served officially in Red Army ranks until the end of the war in May of 1945 and was known used by Soviet partisan groups during the conflict. The German Army, always short of viable automatic weapons along its expanding fronts, took on stocks of captured PPD submachine guns under the MP.715(r) and MP.716(r) designations. "r" recognized them as "Russian" in origin while 715-series guns denoted PPD-34/38 models and 716-series guns were PPD-40 forms.
Unlike other Soviet-originated weapons, the PPD did not go one to see extensive worldwide use due to its limited production numbers and therefore found few global operators. Captured examples were utilized Finnish forces in their two wars (the "Winter War" of 1939 and the "Continuation War" of 1941) against the Soviet Union in World War 2 and Philippine HUKBALAHAP Communist guerillas used the type throughout their 1946-1954 rebellion. North Korea took on the type in unknown numbers and Albania rounded out the list of notable PPD operators.