German 151/20 Experimental Practice?


#1

The picture below shows a German 151/20mm cannon round. The label which is hard to read states " 20mm MG 151/20 AIRCRAFT CANNON EXPERIMENTAL PRACTICE SHELL FITTED WITH w THERMOCOUPLE" The shell has a hollow nose and the thermocouple fits in and runs right down the inside to the base of the cartridge case. Does anyone know what this is for or how it was used.?
Thanks in advance

Buster


#2

Just a guess, but it could have been used to measure bore temperature after sustained firing during testing.


#3

Buster, you got better images for us maybe?


#4

More pictures as requested. The shell body is stamped eel 13f 43 then the Waffenampt stamp if that is the right name for it. An eagle with 70 in the centre?


#5

Buster, I have never seen such ones of German pre 1945 origin so far.
Other’s I had seen looked somewhat different. This one here might also been produced/altered after 1945 for evaluation of captured equipment maybe.

To my understanding these kind of arrangements are used to determine the temperature transaction between a hot barrel/chamber and a chambered cartridge. This is important to find/establish the time/temperature line for the cook off effect.

Just my 2 cent.

Anyone else?


#6

The same thought occurred to me. A thermocouple certainly could not measure temperature while firing, but the modified round could be placed into a hot chamber to measure the temperature rise of the propellant in the case.

By the way, In one of the early NRA reloading guides, there is a very interesting article about an experiment done at the H. P. White Labs about time and temperature relationships during small arms cartridge cookoff. I think they used .22 LR, .38 Special, and .30-'06 cartridges.