12 gauge Ammunition info

Hi ,i am new on here. I am from South Africa and were metal detecting when i found this piece of shotgun shell, can someone maybe assist me with a history please.
Thank you

Gustav Geschow (later trade name Geco) was one of the best known German ammunition factories. The location here is given as Durlach, which today is a suburb of Karlsruhe. Genschow started in 1887 trading in hunting and sporting equipment. Apart from the ammunition factory (taken over in 1903), also a leather equipment factory in Hachenburg as well as a rimfire rifle factory in Berlin existed. Geco later became part of Dynamit AG, the company founded by Alfred Nobel. In 1972 it was decided to close down ammunition production at Durlach (actually the location was Wolfartsweier). The Geco trade name still exists in the products of what is now RUAG at Stadeln near Nuremberg, where the ammunition known under the RWS and Rottweil trade names is made.
The incorporation as “Aktiengesellschaft” as seen in the headstamp occured in 1907.