The 'Suomi KP/-31' (Suomi-konepistooli or "submachine gun Finland") was a submachine gun (SMG) of Finnish design that was in service during World War II. It was a descendant of the M-22 prototype and the KP/-26 production model, which was revealed to the public in 1925. The Suomi-konepistooli KP/-31 is often abbreviated to Suomi KP. The Suomi KP/-31 is regarded by many as one of the most successful submachine guns of World War II and it was so successful that many of its features (including the 71-round drum magazine) were later copied and adopted by the Soviets for their PPD-40 and PPSh-41 submachine guns.The accuracy compared to the mass-produced PPSh-41 was superior however, thanks in part to a noticeably longer barrel, with the same rate of fire and the equally large magazine capacity. The major failing of the Suomi-KP was its high production costs. In 1955 all weapons were convberted also to accept the 36 round box magazine of Swedish design used on the m/45
Marks and Stamps: (L side of receiver) Serial No (Lside of sight bar) SUOMI Tikkakoski (R side of sight bar) PATENT (?worn) 1932| Accession Number: 312 | Period of Use: 1932-1950s |
| Type: Machine pistol/SMG | War Zones: WW2 |
| Country of Origin: Finland | Type Date: 1931 |
| Manufacturer: Oy Tikkakoski Ab, Sakara | Serial Number: 10660 |
| Manufacture Date: Unknown | Calibre/Ammunition: 9mm Parabellum |
| Weight: 4870g | Length Overall: 875mm |
| Cyclic Rate: 900rpm | Length Barrel: 318mm |
| Deactivation Certificate Number: CG 47634 |