The Suomi M31 semi automatic rifle is a product of its time, heavy rugged and reliable. The Finns designed the Suomi sub machinegun in the late 1920s and early 1930s. The original Suomi sub machinegun was designated the K/P 31. The Suomi KP 31 was a great success in the Winter War of 1939-1940. The Finnish Army succeeded despite great odds.
The Suomi M31 is a descendent of the famous KP 31. By today’s standards, it’s weak 9mm pistol cartridge and heavy weight, make it an impractical weapon. It is a great historical piece, a grand relic from a war of national survival.
The M31 has a new receiver and BATF compliant parts. The heavy weight and sturdy construction of the M31 are conducive to reasonable accuracy.
Sweden, Germany, Denmark, used the Suomi KP 31. The Soviet Union copied the design of the drum magazine.