last week had a chance to try a few loads, and- having been reminded that a blow tube is a Good Idea, I took one along.
If you're not knowledgeable of the esoterics of what some at Cast Boolits call 'Holy Black', short lesson:
Black powder, at best, produces a lot of fouling. You either need some way to keep it soft, so the next shot will blow it out(while depositing some new), or you have to wipe the bore between shots. A muzzleloader takes are of this by the greased patch wrapped around the ball; you ram it down, and between the grease and the patch it scrubs the stuff loose so it blows out with the next shot.
With a breechloader, there's an option that(should) let you get a few shots before needing to wipe: blow tube. The deluxe version is a cartridge case with a hole drilled through the base so you can insert the end of a plastic tube: just before you load the next round you slowly blow half a dozen breaths through, so the moisture that condenses softens the fouling, then pull the tube, load, aim and fire.
Not having put together a proper tube, I used something suggested by a guy: pick up a bendy straw and use that. Which worked quite well. I'd use it between shots, then after the five-shot group was finished use a couple of Ballistol & water-wet patches to wipe the bore, then a dry patch, then the next group.
Why not just wipe between shots? Big reason is that with this rifle you have to remove the tang sight to do that. So in the future, a proper blow tube it'll be.