Relatively scarce, this long tapered ‘Express’ cartridge is effectively a longer version of the other English 360 based 6.5mm Sauer cartridges, the 6.5x48R (GSP17) and 6.5x58R (GSP18). This is only known to exist with “H.UTENDOERFFER  NÜRNBERG” hs but the only RWS/Utendoerffer catalogs it was listed in (as empty cases) were from 1922 to 1934 (“as stocks last”). So unless it was produced on a proprietary basis previously, this was not produced until c1921-1930. However, the old headstamp style would seem to imply an earlier introduction and possibly the 1928-1932 catalogs were used to try and dispose of old stock.

It is confirmed as a ‘Sauer’ calibre as the RWS 1928 catalog refers to it as a ‘S&S’ meaning ‘Sauer and Sohn’. Also an undated (prob 1920’s) RWS factory drawing shows this as “S.S.” in the same number sequence as the other Sauer cartridges.