Just as with centre fire rifles your best accuracy load is not necessarily your max load. Experimenting with loose powder is a fun way to find out just what load performs best in your rifle. Pellets are over priced and their so called convenience is not really true. You have all the time in the world to load. Reloading for a second shot is dreaming in technicolour. The challenge of BP is that missing is not an option. The first shot is your only chance. Pre-measuring powder in Lane's tubes gives you the speed advantage back but it still won't give you a second shot in an acceptable time frame.