During the late 1920 and early 1930s, the Walther company worked on developing a military pistol in 9x19mm. They began from the basis of the PP/PPK design, and produced three separate designs, the first two designed “MP” (Military Pistol) and the third being the Armee Pistole (which was followed by an improved model called, once again, the MP). The first MP was simply a blowback PP called up to 9x19mm, and it was not successful. The second model began to look more like the eventual P38 design, and that is what we are looking at today.
This MP has an exposed barrel like the P38, but the barrel is fixed to the frame like the PP. It uses a very unusual locking system, with elements of the Pedersen system as well as elements of a tilting bolt, short recoil design. It uses a recoil spring in the frame, but only one – probably lessons learned on the gun led to the P38’s dual springs. This design was also not successful, but the third one was, and eventually became the P38.
Only two of this pattern of Walther MP are known to exist – serial numbers 105 (this one) and 101.