I would like to know who invented this bullet and who made it in the past and still makes it nowadays.
This is a proprietary bullet typical of Vom Hofe cartridges ( at least I have seen it on Vom Hofe cartridges only).
I know that DWM produced Vom Hofe ammo in the past as did Norma and probably Hirtenberger ( same hds). Wolfgang Romey still makes Vom Hofe ammo ( hds with pentagons)
A friend of mine says it is a brenneke development ( full name Brenneke Torpedo Stopring) and assures that he saw it in an old RWS catalog. So, according to him, RWS made this bullet in the past, but I doubt this can be true.
The box in the picture has a Hirtenberger label, look at the picture on the side. The cartridge DIDN’T CAME from the box,and, as you can see, has a different bullet