Another German shotgun shell - General Ammunition Discussion

Here is another German made shell and I’ve been able to research a little about it. I know it was made by GECO, likely in Durlach, Germany prior to WWII but what interest me the most is that the cup is steel, as is the primer. They both react very strongly to a magnet. The case is paper and it has a roll crimp with a pink topwad (3 1/2 mm) Can anyone educate me on why and when this steel cupped shell was made?

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Top wads - little summary from IAA forum - General Ammunition Discussion - International Ammunition Association Web Forum

Another German shotgun shell - General Ammunition Discussion - International Ammunition Association Web Forum

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