I use that mold with smokeless, using dead-soft lead and drive it at BP velocities from my H&R Handi rifle. Nothing I've shot with it wanders away. There's no reason it couldn't provide good service with BP loads.
For BP work I use the 459-500-3R, but that's out of my Sharps for longer distances than the Handi. I'd absolutely use a lube cookie between the bullet and powder. I leaned a long time ago that both my rifles like a lube cookie over BP and it's become a standard part of my reloading protocol.