It is pretty much as advertised IMHO. Not sure about the breech plug thing.When I pull the breech plug prior to cleaning the rifle, I just let it soak in solvent, then clean it last.

For me, the greatest advantage in using this powder is little worry about rust. It puts my mind at ease to to be able totake a fouling shot, then load it up and leave it that way for an extended period of time with no rust worries.