WWI German Brass Shell Casing 1917

WWI German Brass Shell Casing 1917- This is 22.86 cm tall. Likely for the 77mm field canon. It is well marked on bottom. It is Okt 1917 dated.67% alloy content. ST means stark or strengthened casing. A 231 lot number. HL25 is the makers control mark.Haniel Luege Düsseldorf (brass factory).A nice piece in very good condition.