The tumbling loaded ammunition question is right up there with shooting 5.56 MM in a .223 chamber. A lot of people say not to do it. Yet no one can ever provide a link showing a weapon that was damaged from doing either. I don't do it because I tumble after resizing and depriming. It adds a step, but I don't like handling cases sticky with lube. With that said it isn't going to, "rub the coating off the powder" to tumble for the 10 minutes or so it would take to remove the lube after loading. It's most likely less bumping around than a lot of this 40 year old surplus ammunition has seen.