When they were "Black Talon" the petals were even more fearsome in appearance, and likely caused even more trauma, but the liberals thought that we shouldn't be able to do that much damage on criminals, so they outlawed them. Or, perhaps just intimidated the manufacturer to stop making them.
Black Talon's didn't really do any more damage than a conventional HP, they just looked wicked. In the famous shooting that caused Winchester to pull them from the shelves, the trauma surgeon noted how wicked the bullet looked, but said there was really nothing different about the wound channel.
