ORIGINAL: Pittsburghunter
You can safely weigh most charges but using a powder charge thower with some powders can be dangerous. I don't know why but they tell you not to use your RCBS powder charge measue to throw bp charges. I'm sure it would not hurt anything to use your scale though.
thats because Black powder is highly sensitive to static electricity, black powder substitutes arent as sensitive to static electricity but I still wouldnt use even substitutes in a powder measure. even with modern smokeless powder you still have to cautious with static electricty, but deffinately more so with BP and substitutes. thats why most BP volume measuring tools are made from an acrylic plastic, aluminum or brass these materials are less prone to creating or attracting static electricity. hope this helps answer your question.