...this seemed an appropriate morning to take a pic of the Castle's two Suomi KP/-31 (Suomi-konepistooli) subguns (aka M31), which between them show off two stock styles, two barrel shrouds, and two different magazine approaches. As well as one being non-functional (the one in the foreground) and the other being a semi-auto conversion (hence the extended barrel to meet legal requirements for a non-NFA weapon. Considered one of, if perhaps not the best subgun design from the WWII era, with the...