Interesting projectile

[fernando]

Hi David,
Peculiar thing
Hardly a plumb bob, or any kind of plummet; both rear and 'ball' would not have an irregular shape ... even the arrow head. Those things are perfectly concentric; may spin freely without compromise; isn't that so?
Also hardly a sinker; too many irregular forms again .
An harpoon head would be more likely ... although not definitely that.
Let people carry on digging .