....but it looks like an interesting bullet.

Sounds like an oddball to me! Seems I remember Keith claiming it was the SWC's sharp shoulder that did damage vs the meplat. Maybe this was do e to test that theory?

Many years ago, Lyman offered 38, 44, and 45 caliber bullet moulds similar to what you describe. One of the old Ideal Handbooks I have says that it was designed by A.L.A. Himmelwright, former president of the US Revolver Association. Its benefits (according to the manual) were that it would cut full sized holes in paper targets and game plus, the extended bump on the nose would cut the wind to give it better accuracy at longer ranges.

I don't know how true this is, but I recall reading about someone who cast a needle in the center of a flat-nose wadcutter. Under testing it reduced the air resistance by setting up a cone of disturbed air around the wadcutter, increasing its speed at extended distances. It seems like the extended bump on the nose of a wadcutter would do the same.