PICTURE: 7,65 mm Bergmann M/20 submachinegun. (Photo taken in Sotamuseo). CLICK THUMBNAIL TO SEE LARGER PIC (25 KB).

During World War 1 Hugo Schmeisser developed SMG MP/18-I, which German weapons factory of Theodor Bergmann started manufacturing in year 1918. The German Army soon accepted the weapon and Bergmann factory manufactured some 35,000 (or 25,000 depending source) by the end of Wolrd War 1. This weapon was the first practical machinepistol/submachinegun and even if German Army managed to issue less than 10,000 before end of World War 1 the weapon gained such a reputation that Versailles peace treaty ending the war especially listed submachineguns as weaponry banned from German Armed Forces. The original MP/18-I submachinegun had a weak point in form of magazines, which were far from ideal: It used so-called snail-drum magazines, which Tatarek and Von Benkö had originally developed for artillery version of Parabellum P-08 pistol).

Soon after World War 1 Schmeisser developed Bergmann factory improved version of MP/18-I, which used box magazines. Year 1920 Bergmann sold manufacturing license of this improved MP/18-I now known as Bergmann to Swiss weapons factory S.I.G. (Schweitzerische Industrie-Gesellschaft). After making the deal S.I.G. started manufacturing Bergmann submachineguns in several calibers. S.I.G. manufactured Bergmann submachinegun was exported to several countries including Japan, China and Finland between 1920 - 1927. The Japanese and Chinese Bergmann submachineguns were made in 7,63 x 25 Mauser. Also Estonian Tallinn model 1923 submachinegun manufactured in only small numbers was directly based to MP/18-I. Production of Bergmann submachineguns in S.I.G. factory ended year 1927, S.I.G. offered introduced improved version in 1930, but with very little success. So S.I.G. started producing MKMO submachinegun (which was later developed to MKMS machinepistol). Later in Germany the development of improved MP/18-I led to development of MP/28-II submachinegun.

Finnish Army was not interested about submachineguns in early 1920's, like most Armies of that time it doubted if this type of weapon would be useful to military. However, Suojeluskunta (Finnish Civil Guard) didn't have no such doubts and it bought first 1,000 Bergmann submachinegun already year 1922. By 1932 Suojeluskunta had bought 1,415 submachineguns of this model. Around that point Suomi M/31 replaced Bergmann in acquisitions of submachineguns. Once Finnish Army finally had become convinced about the excellent qualities of Suomi M/31 also Suojeluskunta decided to follow its example and from that on acquire Suomi M/31 submachineguns instead of Bergmanns. When Winter War begun Suojeluskunta Bergmanns were transferred to Finnish Army, which had serious shortage of automatic weapons. Finnish Army issued them to frontline troops for Winter War. Additional 108 Bergmann submachineguns were bought from Switzerland also during Winter War. 100 of them were the same 7.65 mm x 21 Parabellum calibre weapons like the earlier acquired Suojeluskunta Bergmanns, but eight seems to have been 9 mm x 19 Parabellum calibre version. Helsinki-based company "Ilmakunnas" acted as go-between in this deal in which the weapons arrived by very long route via Le Havre and Stockholm. Besides these also 290 Bergmann in 7.63-mm x 25 Mauser calibre were offered from Switzerland, but the Finns decided not to buy them (probably because yet another new calibre for submachineguns would have complicated ammunition supply). During Continuation War Bergmann submachineguns were first issued to coastal troops (until captured Soviet submachinegun soon replaced them in that use) and later they were used by homefront troops. In this way they kind of returned home as basically homefront troops, which contained mostly Suojeluskunta members, which were not fit for frontline duty. After World War 2 Suojeluskunta was disbanded and ownership of remaining Bergmann submachineguns were again transferred to Finnish Army - this time for good. Finnish Defence Forces kept Bergmann M/20 warehoused until they were sold to Interarmco in 1960.

Lindelöf submachinegun, Finnish copy of Bergmann:

Finnish Leonard Lindelöf's machine factory got itself license for production of Bergmann submachinegun in 1922. As the name suggests Leonard Lindelöf owned the factory. Submachineguns that this factory was to manufacture under license were exact copies of Swiss Bergmann M/20. Lindelöf had grand plans of large-scale mass-production of submachineguns and invested accordingly. Early on the prospects for this factory looked positive as the first order arrived swiftly - Suojeluskunta (Finnish Civil Guard) ordered 200 submachineguns indentical to 7.65-mm Bergmann M/20 in December of 1922. But then Lindelöf's factory run into problems - it had promised delivery of these 200 weapons in just 8 months and this proved much too little. Production-wise Bergmann-submachinegun was typical 1st generation submachinegun - complicated weapon with its parts machined from steel. So manufacturing them was slow and demanded large number of tools and machinery. Time needed setting up production had been seriously underestimated and even suspicion of sabotage surfaced. These delivery delays were breach of contract and because of them Suojeluskunta cancelled its order. Heavy hit came when Swiss played Lindelöf out from competition by offering Bergmann SMG with bargain prices to Suojeluskunta in 1923, these bargain priced Bergmann submachineguns filled the needs of Suojeluskunta and lead into situation in which Suojeluskunta no longer had needs to buy more submachineguns for some time. Because of this Lindelöf's lost his only important customer and when first submachineguns made by his factory finally were finished in 1925 the factory had sell them in small quantities to any authorities willing to buy (local level Suojeluskunta organisations, Police, Customs, Coastal Guard, Estonian Police etc...). The factory had about 160 mostly unfinished submachineguns warehoused, but no clients for them.

Year 1930 Lindelöf contacted again Suojeluskunta trying to sell the remaining submachineguns. However Suojeluskunta was loosing interest as the new Suomi submachinegun made Bergmann-design look outdated. Soon after this Lindelöf's factory faced financial difficulties. Year 1932 he contacted again Suojeluskunta, who decided to help the factory by ordering 10 submachineguns, which the factory was to manufacture from its unfinished parts. The factory gave Suojeluskunta 12 already finished submachineguns as a pledge. But once again keeping to the contract proved impossible for the factory - as earlier the delivery was delayed again and again. Suojeluskunta had no other option than cancelling the contract and take position of the 12 submachineguns earlier given as a pledge. The final nail to coffin for Lindelöf's plans was when Suojeluskunta that same year made decision from that on to buy only Suomi M/31 submachineguns instead of Bergmanns. Lindelöf had acquired the tools and machinery made for production of Bergmann submachineguns, but now had to sell the unfinished parts and tools as junk. Lindelöf version of Bergmann submachinegun when compared to the Swiss one was not such a high quality and its magazines were not interchangeable, but otherwise the weapons were identical. The small amount of Lindelöf made Bergmann submachineguns were used the same way as the Swiss made ones and got experienced exactly the same fate in Finland during World War 2 and after it. The estimated total production of Lindelöf submachineguns was only about 60 or 70. While Lindelöf's factory never again manufactured complete firearms it manufactured parts for some weapons still during World War 2.

According Aimo Lahti himself interest for designing submachinegun of his own born because Bergmann submachinegun was so expensive and not very good. Lahti started thinking that he would be able to make a better submachinegun - and he proved to be right. 1^st of June 1921 Aimo Lahti was hired as gun-master to Keski-Suomi Regiment and started developing his idea of submachinegun soon afterwards. First prototype he ordered was a miniature of sort in 7.65mm x 17 (Browning aka .32 ACP) calibre, only about 30 cm long and made by blacksmith in Viiala for him. The first prototype was no work of art but it proved that the basic construction that Lahti had designed was a working one.

Year 1922 he ordered the first real sized prototype (M/22), which was build by Machine workshop Leskinen & Kari in Tampere. It was in 7.65mm x 21 (Parabellum) calibre and had the same rate of fire as in later M/26. Lahti got support from commanders of Keski-Suomi Regiment Colonel-Lieutenants W. Hägglund and E. Heinricks, but they didn't manage to get any financing from state for this development work. Spring of 1923 the prototype was sent to Defence Ministry, but it failed to raise interest. M/22 was not exactly well made or ready for production, but it had plenty of hidden potential.

At June of 1924 Lahti established Konepistooliosakeyhtiö (= Submachinegun Ltd) with some officers of the same regiment. The other shareholders of this new business enterprise were Captain V. Korpela, Lieutenant Y. Koskinen and Lieutenant L. Boyer-Spoof (later changed his sir-name to Poijärvi), the total amount of shares was 150. Lahti got 45, Korpela 45, Koskinen 30 and Boyer-Spoof 30 shares. The new company had a lot of inspiration, but very little finances. Some of business partners even proved to be too inspired - Lieutenant Korpela had to leave from the company after trying to sell the submachinegun abroad without permission of other shareholders.

Lahti was improving his submachinegun-design all the time making several improvements, which were all patented in Finland as soon as they had been invented and development was starting to look ready for mass-production. Konepistooliosakeyhtiö ordered one hundred submachineguns from Ab Tool Oy and at August of 1924 also Finnish Defence Ministry finally got interested. February of 1925 first batch of 13 submachineguns were inspected by Ordnance Department of Finnish Armed Forces. The weapons worked well, but their magazines only worked with individual weapon to which they had been intended and barrels were already slightly corroded. However, they were accepted even with these small problems. Army ordered additional ten submachineguns in October of 1925 and another 39 in March of 1926 and bought even earlier made prototypes (Konepistooliosakeyhtiö and its shareholders were just about broke, so they needed every possible bit of money). From this production series of about 100 weapons most (over 60) ended up to Finnish Army, but also Suojeluskunta (Finnish Civil Guard) and Frontier Guard bought small number. Few weapons of this series were delivered abroad as samples (among them 5 to Estonia). Later submachineguns of this production series were named as M/26 to make them easily separated from M/31 Suomi. Suomi M/26 ended up costing only about 2,200 Finnish marks/submachinegun while Bergmann at that time cost usually more than double (4,500 Finnish marks).

Suomi M/26 never got into real battle use, during World War 2 they were issued troops doing guard duty in home front. Year 1959 the remaining 57 Suomi M/26 were sold to Interarmco and shipped abroad year 1960. This was a one of the darkest moments of Finnish weapons history as along the "ordinary" M/26 also all its one of a kind prototypes were sold without understanding their value. Luckily they were not wrecked and ended up to foreign museums and arms collectors.

Aimo Lahti was not happy with M/26 submachinegun, its feeding process was not as reliable as it should have been and the stock was not robust enough for first grade military weapon. He eliminated the excessive room in front of bolt (which had allowed cartridge sometimes to turn sideways causing jam) and the feeding problems disappeared. The way new way, in which the barrel was attached to receiver allowed barrel to be quickly replaced if needed. Barrel of the weapon received new tilted end, which decreased tendency of muzzle to climb during shooting. The jacket around the barrel was modified to have heavier, easier and more robust structure. However, the most important change was changing of calibre to 9 mm x 19 (Parabellum), as this new ammunition allowed also new type of magazines to be developed. Lahti designed all these improvements plus new 20 round box magazine and 40 round drum magazine between 1930 - 1931. Finally Finnish Defence Ministry became interested, but there was no factory for manufacturing this new submachinegun.

Engineer Oscar Östman, who was leading Tikkakoski Rauta ja Puuteollisuusyhtiö (= Tikkakoski iron and wood industry Ltd) at that time knew Lahti personally and was also very interested about the new Suomi submachinegun. Tikkakoski had manufactured weapons parts for Finnish military earlier, so it had also some experience of weapons manufacturing. Shareholders of Konepistooliosakeyhtiö finally earned from their work when Tikkakoski bought the mass production rights as only manufacturer. This ended the story Konepistooliosakeyhtiö, which had served its purpose.

While Suomi submachinegun was finally getting recognition it earned, the early magazines (20-round box and 40-round drum), which Lahti had developed in early 1930's proved not so good. 20-round box magazines had two versions, which actually had maximum capacity of 25 rounds, but if filled full they didn't work reliably, while when loaded only with 20 rounds they worked rather well. The 20 round magazines were quite small and handy (they weight only some 0,2-kg empty and 0,44-kg when loaded with 20 rounds), but they had too small ammunition capacity and it proved difficult to fill fast, so their production was ended already before year 1939. Production of 20-round magazines was restarted during Winter War, but once Winter War ended the production ended again - this time finally. 40-round drum proved unreliable, but even more difficult problem was with filling it - cartridges had to be inserted in such manner that they stood on tips of the bullets. Smallest mistake would make the cartridges drop in their sides inside 40-round drum magazine, creating mixed pile with only one solution - drop all cartridges off the magazine and start the whole process of inserting cartridges from the start. The 40-round drum wasn't terribly effective for its weight either, it weight 1,0-kg empty and 1,48 kg full while 70-round drum weight 0,87-kg empty and 1,48-kg when fully loaded. The magazines typically used with Suomi M/31 during World War 2 were 70-round drum and 50-round box. From these two, the 70-round drum magazine became the best known magazine for Suomi submachinegun. Yrjö Koskinen (one of shareholders in Konepistooliosakeyhtiö) designed it without Lahti even knowing about this new magazine type before it was finished. Koskinen's drum magazine proved the best magazine used with Suomi M/31 during World War 2 - it was quite reliable, handy (even if somewhat heavy) and offered excellent firepower. In addition unlike many other drum magazine designs this magazine did not allow cartridges loaded inside it to rattle. The Koskinen's drum entered production in year 1936 and remained in production until late 1944. The 50-round box magazine was Swedish design, which Tikkakoski started manufacturing under license in year 1941. 50-round box magazine was not as good 70-round drum, but it was easier and cheaper to manufacture. However, the wartime use proved it too delicate (smallest dent in the wrong place could jam it) and impossible to reload without separate loading tool. Because of these reasons production of the 50-round box magazine was stopped in autumn of 1943. Rest of the war only 70-round drum magazines remained in production and became the most numerous magazine used with Suomi M/31 submachineguns during World War 2. Before and during WW2 Tikkakoski, who was sole manufacturer of Suomi M/31 in Finland, was also sole manufacturer of magazines for it. The equipment used to carry drum magazines of Suomi M/31 during World War 2 was often somewhat improvised combination of hooks, straps and/or rope. In addition gas mask bags (socalled bread bags) and magazine bags originally made for carrying of 10 Lahti-Saloranta light machinegun magazines, were used for carrying submachinegun-magazines. Carrying boxes made from plywood was developed for 50-round box magazines and manufactured for home front troops (Civil Guard) during Continuation War. Only home front troops used these magazine boxes since they would have suited poorly for frontline use, as they were clumsy and made noise (magazines rattled inside them) during movement. While frontline troops usually didn't use these magazine boxes, some seem to have seen use with home front troops. Some sources claim that drum-magazines used in Suomi M/31 would be related to ones used in Thompson submachinegun, but this is false. The only connection might in conceptional level - both Lahti and Koskinen may were likely aware about drum magazine(s) used in Thompson, but its unclear if this effected to their decision of developing drum-magazines for Suomi M/31 in any way. From technical point of view both L- and C-drums used in Thompson are totally different than 40- and 70-round drums used in Suomi M/31.

Magazines Finnish military used with Suomi m/31 submachineguns:

Calling Lahti's submachinegun as Suomi submachinegun (Suomi konepistooli) had spread to Finnish military documents already in year 1925. The first display of new 9 mm Suomi submachinegun and publicity given by Hakkapeliitta Magazine (magazine of Suojeluskunta aka Finnish Civil Guard) in September of year 1930 made Suomi submachinegun practically a household name both among Finnish military and Suojeluskunta organisation. October of 1931 Finnish Army decided to place its first order of 100 new Suomi submachineguns in 9-mm calibre - this led the weapon getting named 9 mm submachinegun m/31. Suomi submachinegun was available from Tikkakoski with several options that included front handle, bipod and two solutions for selector switch, from these Finnish Armed Forces ordered the most simple variation and stick with it. Other variations ended up being sold abroad only in small numbers before World War 2.

Before World War 2 orders for Suomi M/31 were coming in slowly, by 1934 the now more shortly named Oy Tikkakoski Ab had delivered only 375 Suomi M/31 submachineguns to Finnish Army. When Winter War started the amount of these weapons in use of Finnish Armed Forces was not more than about 4,000. Most deliveries included also spare barrels that marking the direct of dispersion. After this each submachinegun was equipped with 2 barrels (original and spare), that both had same dispersion and point of hit. This allowed changing barrel without needing to adjust sights and without loosing any accuracy. Replacing barrel of Suomi M/31 is remarkably easy and fast and obviously designed for soldier in the field to do for his weapon when necessary - both barrel and barrel jacket are locked to weapon with one single simple switch. Also disassembling and re-assembling Suomi M/31 is very easy In fact the only remotely difficult part of doing this is re-inserting of recoil spring, which demands certain technique to make sure that the spring does not get bent.

During the war Finnish soldiers gave grateful feedback, but the feedback also revealed that Suomi submachinegun was not perfect. Tendency for recoil to push the barrel upwards still existed and was seen as largest remaining problem. With sudden barrel corrosions often spotted in January 1940 (benefited to snow and debris getting to barrel at the time) lead into idea that something had to be done (later it was proved that the corrosion had been caused by use of wet ammunition). Both 13^th Weapons Repair Company and Ordnance Department of Finnish Army designed muzzle brakes for Suomi M/31. The Ordnance Department selected its own version to production after some testing. This new muzzle brake was included into all Suomi submachineguns ordered by Finnish Armed Forces after February of 1943. Suomi M/31 ordered by HQ of Home Front Troops and those made for export were not equipped with muzzle brakes even after this, they remained to be exactly same as the earlier version of M/31). The muzzle brake was 95-mm long and 28-mm thick, it added some 55-mm to length of M/31 Suomi. Aimo Lahti was not happy about muzzle brake being added to his invention, in fact his opinion was that it only decreased muzzle-velocity and lead to poorer reliability. Letters SJR (from word suujarru = muzzle brake) were soon added to naming of muzzle braked Suomi submachineguns to make their spare-part supply easier. Later also cheaper, faster and easier to manufacture version of 9-mm Suomi submachinegun called M/42 was developed, but it never got beyond prototype stage.

Summer of 1939 it became clear that submachinegun Finnish Army needed submachinegun, which could be used shooting from vision slits or steel observation cupolas of bunkers. Ordinary Suomi M/31 submachinegun had barrel jacket, which made shooting the weapon from narrow vision slits difficult and also sights and butt structure poorly suited for this use. Ordinary Suomi M/31 submachinegun was also too long to be operated efficiently inside the observation cupolas. So a bunker version with longer and narrower barrel jacket, pistol grip and sights located in left side of the weapon was hurriedly designed. Prototypes were made and tested and the weapon received official approval in September of 1939. But then started Winter War ruining production plans, as resources needed for production were needed elsewhere.

So, when Winter War started only few prototypes of this submachinegun version existed. Yet Finnish troops managed to get in their hands some Suomi M/31 bunker-submachineguns of one sort already during Winter War. Some barrel jackets of bunker versions had already been manufactured and during Winter War Finnish troops installing them to their ordinary Suomi M/31 submachineguns. The resulting weapon was so long that it could not be really used in observation cupolas of bunkers, but at allowed aimed fire through narrow vision slits. During Continuation War situation of bunker submachineguns improved as in January 1941 as part of order of 9,500 Suomi M/31 submachineguns also 500 bunker-version submachineguns were ordered. The early models of bunker submachineguns made for tests had 385-mm barrel jacket, special frame and wooden grips that came in two parts. In mass-production bunker-submachinegun version barrel jacket was 435 mm long, frame and grip structure resembled the ones used in ordinary version and sights were sturdier. Bunker versions of Suomi M/31 remained warehoused to depots of those areas of Finland that had fortifications until 1970's. After this some were given to museums and most went through modification process that made them ordinary Suomi M/31 submachineguns.

This was a special version made for Vickers 6-ton tank (later known as T-26E after equipping the turret with captured 45-mm Soviet tank gun and DT machinegun after Winter War). Those tanks had a firing port specially designed for this submachinegun in their front hull. If crew needed, they could easily remove the weapon from its firing port - when needed allowing it to be equipped with normal barrel jacket and to be used like a normal submachinegun. The tank version had a special barrel jacket designed to fit into firing port (permanently attached to the firing port) and pistol grip. While this weapon with its pistol grip resembled the bunker-submachinegun version, it has normal Suomi M/31 rear sight. When used in the firing port the submachinegun was equipped with simple optical sight. Only few dozen tank-version of Suomi M/31 were made before Winter War and those were the only ones ever made. Soviet DT machineguns were captured in large numbers already during Winter War and proved to be more effective in armoured vehicle use than tank-submachineguns. So, the tank-version of Suomi M/31 never saw mass-production. The total production was probably only about 40 weapons, from which 31 remained in summer of 1940. While the number was small they were intended only for 32 Vickers 6-ton tanks, from which 24 were modified as T-26E. These rare weapons remained included to official Finnish Defence Forces weaponry until 1980's (long after the T-26E tanks, in which they had been used, were all gone). This may have happened simply because nobody remembered to officially inform them not being needed anymore.

Suomi M/31 submachinegun proved to be excellent submachinegun: It had superb firepower, excellent accuracy, good muzzle-velocity and outstanding reliability. Only minus for its users was its weight. Before Winter War it had been intended to role of squad support weapon, which Rifle Squad would have used as kind of a replacement of light machinegun. This proved poor idea, but when the correct role for submachinegun was understood Suomi m/31 proved huge success. While poor as support weapon wannabe it proved remarkably effective once used as individual weapons issued to most capable soldiers. It gave these individual capable soldiers excellent short-range firepower in relatively compact form - light machineguns were still large and heavy compared to it. Suomi submachinegun was unusually accurate weapon as a submachinegun and had longer range than most other submachineguns of its time. This was thanks to quite good ergonomics, rather long barrel (when compared to other submachineguns of that time), small recoil, powerfully loaded ammunition and quite a good sights. Rear sight is fully adjustable and has rather optimistically settings up to 500 metres, while front sight is drift adjustable. In Finnish forests its range typically proved quite long enough and thanks to 70-round drums and fast rate-of-fire Suomi M/31 was able to spray more lead into air faster than most light machineguns of that time. Suomi M/31 become favoured weapon among Finnish troops and soon they got distributed to best soldiers who knew to how to get maximum performance out of them. Before Continuation War armament of Rifle Squads belonging to Finnish infantry regiments got re-planned, now every Rifle Squad got both light machinegun (as support weapon of Rifle Squad) and submachinegun for short-range firepower. Autumn of 1942 Finnish Armed forces finally had all the submachineguns needed according their TO&E, but Suomi M/31 had proved so effective that at that point committee led by General Heinricks went ahead and decided to recommend adding second submachinegun to all Rifle Squads as soon as possible. By end of 1943 enough Suomi M/31 submachineguns had been manufactured for this new table of organisation and equipment to be fulfilled, so then decision about adding a third submachinegun to every rifle squad was made, but this didn't materialise in large scale before Continuation War ended resulted halting of the Finnish weapons production. Early June 1944 number of Suomi M/31 submachineguns in use of Finnish Armed Forces had peaked to bit over 52,600.

Suomi M/31 submachineguns delivered to Finnish Army between 1939 - 1944:

Notice: Those made for HQ of Home Front Troops (pre-war Finnish Civil Guard HQ), ordered by Interior Ministry or exported abroad are not included to these numbers.

Losses in battle, broken weapons and weapons hidden to weapons caches dropped number of Suomi submachineguns to just little bit over 40,100 by 5^th of October 1944. Repairs and weapons returned from weapons caches started slowly raising the number. August of 1951 Finnish Armed Forces had about 50,100 Suomi M/31 submachineguns and about 300 bunker-version of Suomi submachineguns. Some 27,800 of these remaining Suomi M/31 were the muzzle-braked equipped (SJR) version. Year 1953 Finnish Defence Ministry bought unfinished materials from Tikkakoski factory, these included 3,517 Suomi M/31 (that had not been previously finished). Summer of 1957 some 53,600 remained in ownership of Finnish Armed Forces. In mid 1950's new Swedish designed 36-round box magazine (which the Swedes had originally introduced for Carl Gustav m/45 submachinegun) was first bought from Sweden and soon introduced to production under license in Finland. In 1950's and 1960's these new 36-round magazines replaced old 20-round, 40-round and 50-round magazines, which were mostly scrapped. The new Swedish designed 36-round magazine proved excellent - easy to fill with cartridges, handy and reliable. From 1960's to 1990's old 70-round drums and new 36-round box magazines were the magazine types used with Suomi submachineguns. Assault rifles replaced Suomi M/31 in most Finnish military units in 1960's and 1970's, but large number still remained warehoused for reserves of Finnish Defence Forces until late 1990's. In 1990's AKM-type assault rifles bought from Germany and China finally replaced by then very old-fashioned Suomi M/31 submachinegun. Even if it isn't no longer part of weaponry used by Finnish military some Suomi M/31 still remain warehoused for the Finnish reserve police. Even today Suomi submachinegun had legendary reputation among Finns. Few years ago in a poll Finns voted Suomi submachinegun as the second most important Finnish invention of 20th century.

Before World War 2 orders of Finnish military were so small that capacity for export production existed, so Tikkakoski offered Suomi submachinegun foreign customers. Starting from 1931 several introduction tours were done by Aimo Lahti and Tikkakoski representatives to other European countries (mainly to Germany and Baltic countries), but projects for sales to more far away countries existed also. However gaining good export deals failed. Only somewhat large deal following from these efforts was for Estonian Armed Forces, which bought 485 Suomi M/31 submachineguns, which were delivered in September of 1938. Tikkakoski developed two versions (both called M/33) of Suomi submachinegun for Persia. These two M/33 prototypes had upwards pointing box-magazine on top of the weapon and bipod below barrel. The main difference between two M/33 prototype versions was pistol grip, which one version had and another didn't. But due to changes in Persian political situation (coup) the actual order for M/33 from Persia never came. Smaller deals were also done with customers like Polish State Police (20 Suomi submachineguns delivered in 1933), but the success had to wait until World War 2. According what is known small numbers of Suomi submachineguns found their way to Chaco War (Bolivia vs. Paraguay 1932 - 1935) and to Spanish Civil War (1936 - 1939).

During Interim Peace and Continuation War Tikkakoski also exported Suomi submachineguns abroad. Many of largest deals were made to insure getting vital machinery or raw materials in exchange. Export permits given in that time included:

In addition Romania wanted to buy 5,000 Suomi M/31 submachineguns in year 1942, but the deal didn't happen as orders of Finnish military were a priority. For the same reason many of the planned export deals listed above could not be filled. In addition July of 1942 Finland donated 120 new Suomi M/31 submachineguns to German AOK Norwegen located in Finnish Lapland. Large number of the submachineguns sold to Germany seems to have ended up to SS and Waffen-SS, as they were typically issued more mixed weaponry than Wehrmacht (German Army). Both 50-round box magazines and 70-round drum magazines seems to have been exported with the weapons.

Swedish versions:

Danish versions:

Swiss versions:

Soviet versions:

Unlike some sources have claimed Finland never acquired any of the license-made Suomi submachinegun versions and none of them saw any use with Finnish military. Only possible exception to this rule might be (likely very small number) of Husqvarna M/37-39 Swedish volunteer unit (SFK) might have brought among its weaponry to Finland during Winter War. As SFK left its weaponry to Finnish military after that war few M/37-39 might have seen Finnish use during Continuation War. At least some of the weapons delivered to Croatia (and possibly Bulgaria) seem to have ended to German hands during the war.

Writer's personal experiences concerning shooting Suomi M/31 submachinegun: As to be expected, the first impression tends to be how surprisingly heavy this weapon is - due to the extremely robust structure with milled steel parts. Especially the version with muzzle brake is also quite muzzle-heavy. Due to these reasons recoil is minimal. The muzzle climb still exists while shooting on full-auto mode, but considering the high rate of fire it is yet easily manageable and therefore the weapon is easy to control. Accuracy is remarkable to submachinegun firing 9 mm x 19 cartridge - in semiauto mode hitting man size target with each shot from distance of 150 meters is normal. From 50 meters keeping simultaneously four falling-plate type targets down until running out ammunition proved easy. Hitting all four targets with one long burst proved not too difficult either. Sight are simple but effective, aiming proved fast and simple. Triggers feel seem to be relatively heavy, but they are two-stage and the "step" is quite obvious. Old magazines are weakest part of the design - while 70-round drum magazines tend to be extremely reliable, they are difficult to fill with ammunition. 50-round box magazines are difficult to fill with ammunition without a proper tool, but once proper tool and technique are used, are not too difficult. Obviously 36-round box magazine is both easy to fill and use. Typically just about any individual magazine will work in any individual weapon - but there are exceptions to this rule. Reliability seems to be on par with the reputation. Shortly said - this is one of the few World War 2 era small arms, which I would not mind possibly using as a combat weapon even today.