These are also cases from Schurk.
Introduced by RWS in 1964 but discontinued by them around 2003. It was also adopted by Hirtenberger until around 1998. Based on the 6.5x57R case necked down from the prototype developed by Munich gunsmith, Adam Schurk in the late 1930’s. There are a number of prototypes of this case based on the 6.5x57R Mauser produced by Schurk in the 1930’s with “RWS 6.5x57R” hs, some with the “6.5” overstamped with “5.6”.