7.8x53 Hebler-Lorenz

Now that I’ve positively identified my new round as this 1889 experimental, I thought I should write a short article for the IAA Journal, with accompanying pictures. Does anyone have any interesting information on the 7.8 or 8mm Hebler-Lorenz cartridges that I could add to the little I’ve found so far?

Is this the 7.7x53Hebler #4? I have this cartridge & the only ref I can find for it is M

Hi Will, welcome.
I wish I knew what model it is. I have heard of a few 1887 dated rounds, but not 1889. Without other specimens at hand I can’t be sure if mine is significantly different. Specific info on these rounds is hard to find.