Does anyone know if Blackhorn 209 is good to go for side locks, or is it best for inlines only?
I have never used the BH209, but, it is a loose powder, therefore, I see no reason why you can not use it for a Hammer. I have always used Pyrodex P for my side Hammer guns because it is a finer grain powder and it gets down in to the Nipple port better and almost prevents any misfires.