Illuminating .303?

A few months ago I posted some photos of some cartridges I got from battlefield north of France.
Yesterday I got a new one (right on the first photo) in very bad condition.
I decided to open it and here is what I found.
A long copper tube with a kind of paper around it to fit the case.
It looks like there is some powder inside the tube.
It is also very similar to another one I also got from battlefield but with a different diameter (left one on the last photo).
H/S are K15 VII, G15 VII and K-15 VII.

Could it be a local manufacture of something like an illuminating cartridge or something else?

I have a vague recollection of a similar round posted on the BOCN forum some years ago, I have searched but I cant find the post. What makes you think it may be an Illuminating .303 round. I have looked through the .303 books I have and can not find anything resembling this round but there must be some information somewhere.


Sabotage round, maybe? The tube looks like a blasting cap from what I can see in the pictures. I’d be careful. Bruce.

I got good information from pierrejean; the tubes look like tubes used in detonator n°22 and 110 (BA Temple n°2 page 61 and 63).
Does someone have the exact dimensions of those copper tubes (drawing TWD 5374…) to compare with mine?