Editing Submachine gun (section)

===World War II===
[[File:Beretta 38.jpg|thumb|A Beretta Model 38, one of the most successful Italian weapons of World War II]]

Changes in design accelerated during the war, with one major trend being the abandonment of complex and finely made pre-war designs like the [[Thompson submachine gun]] to weapons designed for cheap [[mass production]] and easy replacement like the [[M3 Grease Gun]].

While the Italians were among the first to develop submachine guns during World War I, they were slow to produce them under [[Mussolini]]; the 9mm Parabellum [[Beretta Model 38]] (MAB 38) was not available in large numbers until 1943. The MAB 38 was made in a series of improved and simplified models all sharing the same basic layout. The MAB 38 has two triggers, the front for semi-auto and rear for full-auto. Most models use standard wooden [[Stock (firearms)|stocks]], although some models were fitted with an MP40-style under-folding stock and are commonly mistaken for it. The MAB 38 series was extremely robust and proved very popular with both [[Axis powers|Axis]] and [[Allies of World War II|Allied]] troops (who used captured MAB 38s).<ref>Dunlap, Roy F., Ordnance Went Up Front, Samworth Press, (1948), p. 58</ref> It is considered the most successful and effective Italian small arm of World War II. During the later years of the war, the [[TZ-45]] submachine gun was manufactured in small numbers in the [[Italian Social Republic]]. A cheaper alternative to the MAB 38, it also sported an unusual [[grip safety]].

[[File:MP 40 AYF 2.JPG|thumb|An MP 40 submachine gun with its stock extended]]
In 1939, the Germans introduced the 9mm Parabellum [[MP38]] which was first used during the [[invasion of Poland]] of September that year. The MP38 production was still just starting and only a few thousand were in service at the time. It proved to be far more practical and effective in close-quarters combat than the standard-issue German [[Karabiner 98k]] [[Bolt action|bolt-action rifle]]. From this experience, the simplified and modernized [[MP 40]] (commonly and erroneously referred to as the Schmeisser) was developed and made in large numbers; about a million were made during [[World War II]]. The MP40 was lighter than the MP38. It also used more stamped parts, making it faster and cheaper to produce.<ref name="Century 2000. pages 118-120">Military Small Arms of the 20th Century. 7th Edition. by Ian V. Hogg & John S. Weeks. Krause Publications. 2000. pages 118–120</ref> The MP38 and MP40 were the first SMGs to use plastic furniture and a practical folding stock, which became standard for all future SMG designs.<ref name="Century 2000. pages 118-120"/> The Germans used a large number of captured Soviet PPSh-41 submachine guns, some were converted to fire 9mm Parabellum while others were used unmodified (the German [[7.63×25mm Mauser]] cartridge had identical dimensions to the 7.62×25mm Tokarev, albeit slightly less powerful).

During the [[Winter War]], the badly outnumbered Finnish used the [[Suomi KP/-31]] in large numbers against the Russians with devastating effect. Finnish ski troops became known for appearing out of the woods on one side of a road, raking Soviet columns with SMG fire and disappearing back into the woods on the other side. During the [[Continuation War]], the Finnish [[Sissi (Finnish light infantry)|Sissi patrols]] often equipped every soldier with KP/-31s. The Suomi fired 9mm Parabellum ammunition from a 71-round drum magazine (although often loaded with 74 rounds). "This SMG showed the world the importance of the submachine gun in modern warfare", prompting the development, adoption and [[mass production]] of submachine guns by most of the world's armies. The Suomi was used in combat until the end of the [[Lapland War]], was widely exported and remained in service to the late 1970s. Inspired by captured examples of the Soviet [[PPS submachine gun]], a gun that was cheaper and quicker to manufacture than the Suomi, the Finns introduced the [[KP m/44 submachine gun]] in 1944.

In 1940, the Soviets introduced the [[7.62×25mm Tokarev|7.62×25mm]] [[PPD-40]] and later the more easily manufactured [[PPSh-41]] in response to their experience during the Winter War against Finland. The PPSh's 71-round drum magazine is a copy of the Suomi's. Later in the war they developed the even more readily mass-produced [[PPS submachine gun]] - all firing the same small-caliber but high-powered Tokarev cartridges. The USSR went on to make over 6 million PPSh-41s and 2 million PPS-43s by the end of World War II. Thus, the Soviet Union could field huge numbers of submachine guns against the [[Wehrmacht]], with whole infantry battalions being armed with little else.<ref>Bishop, Chris (2002). The encyclopedia of weapons of World War II. New York: MetroBooks. {{ISBN|978-1-58663-762-0}}. Retrieved 19 October 2014.</ref> Even in the hands of [[Conscription|conscripts]] with minimal training, the volume of fire produced by massed submachine guns could be overwhelming.

[[File:Sten Mk II IMG 4764 (Nemo5576).jpg|thumb|A Sten Mk II, the second most produced submachine gun of World War II]]
Britain entered the war with no domestic submachine gun design but instead imported the expensive US M1928 Thompson. After evaluating their battlefield experience in the [[Battle of France]] and losing many weapons in the [[Dunkirk evacuation]], the [[Royal Navy]] adopted the 9mm Parabellum [[Lanchester submachine gun]]. With no time for the usual research and development for a new weapon, it was decided to make a direct copy of the German [[MP 18#Evolution|MP 28]]. Like other early submachine guns it was difficult and expensive to manufacture. Shortly thereafter, the simpler [[Sten]] submachine gun was developed for general use by the British armed forces, it was much cheaper and faster to make. Over 4 million Sten guns were made during World War II. The Sten was so cheap and easy to produce that towards the end of the war as their economic base approached crisis, Germany started manufacturing their own copy, the [[MP 3008]]. After the war, the British replaced the Sten with the [[Sterling submachine gun]].

The United States and its allies used the Thompson submachine gun, especially the simplified [[M1 Thompson submachine gun|M1]]. The Thompson was still expensive and slow to produce. Therefore, the U.S. developed the [[M3 submachine gun]] or "Grease Gun" in 1942, followed by the improved M3A1 in 1944. While the M3 was no more effective than the Tommy Gun, it was made primarily of stamped parts and welded together and could be produced much faster and at a fraction of the cost of a Thompson; its much lower rate of fire made it a lot more controllable. It could be configured to fire either [[.45 ACP]] or [[9mm Luger]] ammunition. The M3A1 was among the longest-serving submachine gun designs, being produced into the 1960s and serving in US forces into the 1990s.

[[File:MAS-38.jpg|thumb|The MAS-38 was France's only WWII submachine gun design, but France was defeated before very many were manufactured.]]
France produced only about 2,000 of the [[MAS-38]] submachine gun (chambered in [[7.65×20mm Longue]]) before the Fall of France in June 1940. Production was taken over by the occupying Germans, who used them for themselves and also put them into the hands of the [[Vichy France|Vichy French]].

The [[Owen gun]] is a 9mm Parabellum Australian submachine gun designed by [[Evelyn Owen]] in 1939. The Owen is a simple, highly reliable, open bolt, blowback SMG. It was designed to be fired either from the shoulder or the hip. It is easily recognisable, owing to its unconventional appearance, including a quick-release barrel and butt-stock, double pistol grips, top-mounted magazine, and unusual offset right-side-mounted sights. The Owen was the only entirely Australian-designed and constructed service submachine gun of World War II and was used by the Australian Army from 1943 until the mid-1960s, when it was replaced by the [[F1 submachine gun]]. Only about 45,000 Owens were produced during the war for a unit cost of about A$30.
[[File:Japanese smg and bayonet.jpg|thumb|A Type 100 submachine gun with bayonet]]

While most other countries during World War II developed submachine guns, the [[Empire of Japan]] had only produced one, the [[Type 100 submachine gun]], based heavily on the German MP28. Like most other small arms created in Imperial Japan, the Type 100 could be fitted with the [[Type 30 bayonet]]. It used the [[8×22mm Nambu]] cartridge, which was about half as powerful as a standard Western 9mm Parabellum round.<ref name=":1">{{cite book|last1=Henrotin|first1=Gerard|title=The Nambu Type 14 pistol explained|date=2010|publisher=HL Publishing|page=5}}</ref>  Production of the gun was even more inadequate: by the war's end, Japan had only manufactured about 7,500 of the Type 100, whereas Germany, America, and other countries in the war had produced well over a million of their own SMG designs.<ref name="Miller2007">{{cite book|last=Miller|first=David|url=https://books.google.com/books?id=Kqm5J6W1VuQC&pg=PA279|title=Fighting Men of World War II: Uniforms, Equipment and Weapons|publisher=Stackpole Books|year=2007|isbn=978-0-8117-0277-5|volume=1|page=279}}</ref>

The German military concluded that most firefights took place at ranges of no more than ~{{cvt|300|yd}}. They therefore sought to develop a new class of weapon that would combine the high volume of fire of the submachine gun with an [[intermediate cartridge]] that enabled the shooter to place accurate shots at medium ranges (beyond that of the {{cvt|100|–|200|yd}} range of the typical submachine gun). After a false start with the [[FG 42]], this led to the development of the {{lang|de|[[StG 44|Sturmgewehr 44]]}} [[Select fire|select-fire]] [[assault rifle]] (assault rifle or storm rifle is a translation of the German {{lang|de|Sturmgewehr}}).<ref>{{Cite web |last=Moncure |first=Billy |date=2019-02-10 |title=StG 44 - Approved by Hitler, The Gun that Revolutionized Modern Rifles (includes footage) {{!}} War History Online |url=https://www.warhistoryonline.com/instant-articles/stg-44-the-nazi-gun.html |access-date=2024-05-10 |website=warhistoryonline |language=en}}</ref> In the years following the war, this new format began to replace the submachine gun in military use to a large extent. Based on the StG44, the Soviet Union created the [[AK-47]], which is to date the [[List of most-produced firearms|world's most produced firearm]], with over 100 million made.