Sander has it right. I would add that most shotgunners wish the dram equivalent would just go away. It's an antiquated way of trying to convey the velocity of the shot; i.e. if X drams of black powder would produce 1200 fps velocity in a particular load, they call it an X dram equivalent load. 1200 feet per second says it all, much more clearly. Why the hell don't the manufacturers stop using dram equivalent?