The story is that massed automatic fire from infantry armed with these things inspired the Germans to adopt an intermediate range version quick, to use on the Eastern Front.
(This is a great site for firearm pix you'll never see elsewhere.)
The story is that massed automatic fire from infantry armed with these things inspired the Germans to adopt an intermediate range version quick, to use on the Eastern Front.
(This is a great site for firearm pix you'll never see elsewhere.)
I believe it was the Finns during the Winter War of 1939-1940 whose effective use of the Suomi M/31 caused the Soviets to redesign their limited issue Degtyarov PPD-34/38 submachine guns (basically a copy of the Suomi M/31) into what became the PPD-40 which was quickly replaced by the PPsh-41. 
Notice the basic evolutionary line from the Finnish Suomi M/31 above and the Soviet PPD-34/38 second from top, the Soviet PPD-40 third from top and the Soviet PPSh-41 below:
