Spent the day in Maryland's Great Valley with my crew, metal detecting on Federal property around the edges of a Civil War battlefield.
It was a glorious day.
Yes, professional archaeologists use metal detectors; the only difference between what we do and what relic hunters do is that we make a precise record of where we found every artifact, in this case with a high-end GPS unit. Above, an ordinary dropped (not fired) Federal bullet. Dropped bullets show you where soldiers were standing while they tried to load their weapons, and fired bullets show you where people were aiming.
Piece of iron case or cannister shot, from an artillery shell.
North Carolina button, something of a mystery since so far as I know no North Carolina troops fought here.