BH is a detuned smokeless powder. It's the only BP sub that has to be cleaned with smokeless solvents. All the rest are can be cleaned with soap and water, or just water if you like.

I guess to be a BP sub all it needs to do is measure in volume the same as BP with similar power.

It's biggest advantage is no swabbing between shots with no loss in accuracy. You can take 100 shots with no swabbing, and the 100th shot will load as easily as the first. It's also very consistent, and collect no moisture.

Hardly what BP, or subs should do, but there it is.

Money can't buy you happiness, but it can buy you a hunting license and that's pretty close.