As Steve Meyer said, 1936 German made guns would have specified 70mm if the gun was chambered for 2 3/4" shells. Sixty five mm is the default setting unless marked otherwise. Don't mess up the gun by opening the chambers to the longer length. Either reload the shorter loads yourself or buy them from sources like William Larkin Moore, RST and a few others. I use 7/8oz loads in my old German 16ga with shells from the sources given. Upland birds never know what hit them and that includes SD pheasants.
