Sorry to double-post, but just wanted to mention again that I think your powder charge is a bit light, and you might want to try a 100 grain charge, in conjunction with patching and/or trying a "chewed" ball. Also, shooting with a paper cartridge (as Curator mentions) could help quite a bit, depending on the thickness of the paper, and the number of wraps, you can adjust the thickness of your paper-patch. I've had good luck with that. I use paper bag, either the big heavy grocery bags, but usually thinner lunch-bag. And of course paper cartridges really speeds up the loading process. No duh! In my Bess they are not as accurate as a patched chewed ball, but if I remember correctly, (haven't shot them for a while) I can still kill, or badly scare a paper plate at 50 yards. They don't have to be made authentic and complicated like originals, just wrap the paper around a dowel, glue, seal one end, drop in your ball, powder, fold the end over. Again, I would agree, I don't think it's you, I believe the musket is inaccurate beyond 25 yards with the load and method you are using now.