The old „Bleistiftpatrone = pencil cartridge“ 6.5x70R was designed in Suhl about 1911 to allow for light, slim drillings and combinations. It was a pure roebuck number with ballistics comparable to the .25-35 Win. It used 6.64 mm = .261” bullets like several other German “6.5” cartridges. A handloader may use Hornady .258” 117 gr bullets and 28 gr 4064 for about 2200 fps. Apparently it was more popular in Austria than in Germany. The German ammo companies declared it obsolete in 1934, “axailable only as stocks last”.
About 25 years ago Krieghoff, Ulm and Norma resurrected the old case, but necked it down to use .243” bullets. Intended as a special varmint - roedeer cartridge for Krieghoff's insert barrels in their full power drillings, it was not a real success. So the 6x70R is obsolescent now too, ammo and empty cases hard to find.