Identification German WWI Artillery Shell casings brass and steel

Hello and thank for taking time to read this. I bought two shell casings at an online auction, one brass one steel, they seem to be from the same caliber, possibly 77mm? Any identification help would be much appreciated, thank you!

Were there really piles of spent artillery shells littered across the battlefields of WW1? If so, what'd they do with them all after the Armistice? - Quora

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Artillery shell cases, fuzes, primers and tubes. – Stephen Taylor, WW2 Relic Hunter

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WW1 German brass shell case inscribed PATRONENFABRIK KARLSRUHE 1917 decorated with a large Chinese style dragon H50cm; and another brass 105mm shell case dated 1968 applied with twenty-eight Staybrite - Militaria, Weapons

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pom-pom artillery shell