[Vlim]

Just recently a question came up about shooting and testfiring a Luger's upper only.

The Luger upper (barrel-receiver-toggle) is a fully functional firearm on it's own. Neither the trigger, frame or sideplate are needed to fire a single chambered round.

This aspect of the Luger caused many accidents in the past, especially with German police forces in the interbellum period. It lead to the development of the sear safety for police Lugers as a result.

In his weapons training manual, Schmitt wrote a small chapter on the demonstration of this effect, with some dramatization added to enhance the experience of the onlookers. He wrote:

I prefer to demonstrate the following accident from reality at the shooting range (the chamber is prepared):

Assumption: A pistol cleaning is being carried out. A (demonstrator) field strips the pistol in front of the audience, with exception of the barrel with receiver and toggle (the rear toggle pin, receiver, toggle should not be removed):

Then he removes the loaded magazine, but leaves a round in the chamber without alerting the audience. When asked, many onlookers will say that the shown part (barrel-receiver-toggle) is harmless. The demonstrator then places the upper in the special built retainer and presses, assuming the sear (S) is being cleaned, on it:

The shot will fire, the 2 body sized targets (F) opposite will receive stomach hits.

The more unexpected the shot from the small pistol part will sound, the more convincing the effect of the danger of the supposedly well known pistol will be.

Building the retainer (see image 19):
A wooden slate Q will be nailed to a table top at the rear end. It will absorb the recoil. Close to both sides of the barrel 2 sets of nail are hammered in (N) to prevent sidewards moving of the barrel.
The front pair is to be bent over the barrel to prevent it from jumping upwards.
The rear pair serves to limit sideways movement, but most not block the toggle from jumping upwards.
The test performed this way is harmless (his words..).

If I would demonstrate it, I'd use an empty primed case instead, but I guess that the sight of a bullet tearing through 2 dummies was also very convincing at the time...

A small interpretation of the original 1928 design I knocked up to show the basic idea of the demonstration setup is added below. Note that the original document described to bend the front two nails over the barrel. I decided not to ruin the finish on the demo upper, so I skipped that part.