JMason, you should be using real black in your flintlock. You will shoot it better with less pasue. Use 4f in the pan and 2f with your load. I Assume its a 50 cal or bigger?
Len, APP is good powder for inlines. I use the 2fg in my 45 cal knight but the APP powder is coarser than others. I would try both 2f and 3f if you have them. (Obviously not together!!!) They work great and you do not have to clean right away. But I still wouldn't leave it too long after shooting.
The new Blackhorn 209 is the cat's a$$! Real clean and accurate.
Member 7MM STW Club