Got to thinking the other day, after Chapuisarmes's post about a Woodleigh Hydro as a profile for a cast bullet.
I posed the question to Veral Smith, of LBT moulds in Idaho, and this is the response I got, verbatim.

"A bullet with that shape could not be knocked out of a mold, nor could the mold be opened. As I see it, the principle behind that profile, which has a very poor flight form, by the way, is that it causes a fairly hard solid bullet to expand to an ideal mushroom slightly larger than bullet diameter, which is extremely deadly and will consistently penetrate straight and true. -- It would not be good with lead however, because of the weaker metal. One could get the same effect within a much more limited velocity range than the woodleigh, by hollow pointing one of my LFN profiles in a lathe, and experimenting with the hollow point shape till bullets expand slightly. You'd have to use a low antimony alloy heat treated to around 16 bhn or the expanded portion would crumble and not hold shape."

Thought this might be of some interest as to why it most likely would not work as a cast bullet.
I think the other fly in the ointment might be that the Hydro's are a patented product, so copying one as a cast bullet might just not be the correct thing to do.

Regards,
David.