It was probably just an empty shell, not even a live one.
Possibly...
My grandfather had a WW-I artillery shell souvenier that he kept on a shelf above his workbench in the basement. I don't know exactly what it was, but it was about 2½" in diameter, and perhaps 8~10" in length. I have no idea whether it was loaded or not. And I don't know what happened to it when he passed away. But I can still clearly picture it sitting on that shelf where it sat for decades.