NEVER reverse engineer something the way you are trying to do. Instead, look at various powders, bullet and powder manufacturer load data, and decide what loads would suffice for the performance you desire. Never think you can duplicate a recipe by looks. Work up your loads using known information, not looks. You will find many manufacturers use blended powders that you cannot get your hands on. They have additives you cannot sometimes buy and rarely detect.
Good reply. Now what can I use .308 blank powder for?