Can an iron cannon ball be x-rayed? I have one in the basement. I have never dropped it. How would I know if there is a charge in it, or that it is just weight?
With care, it “might be” a hollow (powder-filled) old shot. Does it have ANY kind of a screwed-in or plug or fuze? Those would indicate it might contain powder (explosive) inside. A solid, smooth outside is probably a solid interior. And so “somewhat safer”
Problem is, the explosive inside either becomes unstable and more likely to blow up with little provocation like heat, pressure, shock, or tampering, or becomes inert and less likely to blow up. Happens both ways.
A dental xray is not likely to be strong enough. Medical xray might be. NDE xray or gamma ray specialist is definitely strong enough to see through - but they’d be expensive. Do you have a Civil War collector’s group in your area? Rev War group? Try a local arms show - ask a collector/sales exhibitor who has old cannonballs or muskets for sale. They can get you in the right group to find experts. If yo prefer NOT to go straight to the police or local sheriff.