A while back we had an excellent guest article by Michael Heidler on the Haenel ZfG-38 training machine gun. Well, we also happen to have found a pretty detailed line drawing of another Haenel training gun, this time in 9mm and labelled “Zielfeuergerät Schmeisser”. It used a very extended 100-round stick magazine, although the bolt and trigger mechanisms look basically identical to the 8×57 ZfG-38.
This gun (along with the 8mm version) was used in training exercises, either as a remotely triggered simulator controlled by an instructor or as a warning device with the trigger connected to a tripwire. As you can see form the drawing, the trigger mechanism is designed so that it can be fired by pulling a wire either from in front or behind the gun. Here is a photo of an example of one of the 9mm guns, courtesy of Michael Heidler:
The cartridge used in these was the crimped 9mm blank originally developed for the MP28,II (photos again courtesy of Michael Heidler):