10.15 x 61R

Is this a military or commercial cartridge? I have a primed case headstamped “HAGEN 10-15”. Also, how old is this headstamp, and who were/are “HAGEN”?

Falcon, what you have there is a 10.15x60.5R LV4. It is part of a series of sporting cartridges and is not the same as the 10.15x61R Jarmann. Here is some background on this cartridge, followed by Hagen:

*****************10.15x60.5R LV4
This scarce cartridge was apparently only produced by Utendoerffer/RWS and Egestoff. Egestorff listed this case in a c1901 catalog but discontinued it shortly after. Previously this cartridge has generally been considered interchangeable with the 10.15x61R La No4 (aka 10.15mm Jarmann : SC16) even though catalog drawings show this uses a slightly narrower case.

However cartridges with “HAGEN 10-15”, “LV”, “LV 10 CHRISTIANIA 15”, “LV 10.15”, Egestorff and “HVEDING No4” hs do exist that match the LV4 profile and are sufficiently different to be considered a different calibre. The differences of the LV4 from the La No4 are:
-c0.2mm narrower case at shoulder and head.
-c1.0mm shorter case length.
-c1.5mm lower shoulder.
-more gradual shoulder (c6.9mm vs 5.2mm).

An 1880-90

WBD: That is excellent background information.

So as far as I can tell, my cartridge was made by RWS. What time frame would it have been in?

Yes, it is most likely that this was produced by RWS in the c1890-c1920 period. Here is some more info on the LV series:

****************LV Series
This series of five cartridges was shown in the c1900 RWS/Utendoerffer catalog where they are shown as ‘LV’ for Norway.

The significance of ‘LV’ is not confirmed for sure but it has been speculated and is likely to be correct that it stands for "LARSENS V

Thanks WBD, excellent response.