German F.K. 16 nA 75mm brass casing

This is an uncommon brass case for the German 7.7 Fieldkanone model of 1916, a World War One artillery piece and mainstay of the German army which was rebarrelled in WWII to become the 7.5 cm F.K. 16 nA (neuer Art, or “new model”) gun. Case is dated 1938 and clearly Waffenamt marked. 75mm x 200mm rimmed case. There were less than 300 of these guns in service at the outbreak of WWII. Primer removed as per EEC edict circa 1980’s so this artifact left Europe within the last 40 years and is very uncommon to see in North America.