The coolest things I dug up so far we’re three .50 BMG shell casings on Takao mountain from a Des Moines armory, and stamped with ‘44 and ‘45. Worthless, but an awesome find. Still trying to figure out how they got there. Shot down plane, dumped from an injured plane...no idea still...
Makes a great pen holder for the desk.
WWII U.S. fighters generally dump ammo casings out of ejection ports in the wings when firing. In bombers, I think the casings just pile up in the fuselage.