Started to think about it. Of one makes a needle with a heavy tip (tungsten? gold?) and a rear end of something lighter (titanium?), maybe it would stabilize in a barrel with no rifling. Maybe we�ll be able to get hold of some surplus depleted uranium in the middle east region soon?
It may be difficult to cut the rifling in that kind of caliber.
It may be (?) possible to shoot that thing with a primer only and still getting considerable velocities, waddyathink?