if you blow it up you can see 5 balls and five sides
Us`n kids here in the mountains used to get big apples from our orchard, run a spear thru it and use it for penetrating wooden walls of old barns. Same principle. F=MA ... So I recognized the shaft holes right away. The many sided Roman spear weight facilitated a rapid spear-end jab-and slide-on means of battlefield operation coz weight`s sitting on the ground meant an open hole was always upward and level.
That’s what she said. I mean, thanks! I did blow up that very nice wiki-image, and there’s a sort of sphere there, so, could be, but maybe for this gizmo it wasn’t for the weight as described, but for the sound it made in flight.