This here is a Swiss thumb removing device called the SOLA .357mag. It is a side jointed Luger chambered in .357 magnum.
It is one of the few European semi auto magnums out there. Not that there are that many semiauto magnums in the world anyway.
If you know any semiauto magnums other than the mateba, automag, grizzly, sola, fosbery, deagle pls say it.