Originally posted by Fishu
Except they had to look at Suomi KP/31 before making their PPSh 
http://guns.connect.fi/gow/suomi1.html
Hmm. I didn't know that Suomi was desigled in 1931.
Russian analogue of Suomi was PPD-34 adn PPD-40 that had a drum-magazine inspired by Suomi.
Africa (some people here may remember him) bought a disabled PPSh-41, bolt deformed, barrel drilled and drum has no spring. I disassembled it and was really surprised of how simple it is. No more then 5 parts. Finish is very rough, you can easily tear your clothes with burrs. This thing was designed for production in any metal-bed factory. Barrel is chromed because of low quality of steel finish.
PPSh is only three letters in Cyrillic, ППШ,
Pistolet-
Pulemet
Shpagina, Shpagin's Pistol-Machinegun.
Interesting fact is that in 1941-42 each PPSh came with 3 drums that could fit this gun only, they were not interchangable and couldn't be used with another PPSh. They solved this problem only in 1943.
Another thing is that it fires from open bolt, and the gun literally jumps in your hands when you pull the trigger, but in close combat it wasn't important.
Here you can sometimes see people guarding railway tunnels and bridges armed with PPSh or Mosin 1891/30 three-line rifles... Reliable weapons that don't need almost any maintenance.
Edit: PPSh is pronounced "pe-pe-sha", stress on last "a".