Once went to a rifle range with a friend to try a new rifle (not BP but cartridge) I had bought. Saw a man there firing a flintlock. He swabbed his bore between shots, and I couldn't understand why. This friend of mine had at the time been hunting and shooting competition with muzzleloaders for almost 30 years. He just shook his head and laughed. When i asked him why he was laughing, he told me that it was 'just plain stupid' and the man didn't know 'squat' about muzzleloaders as swabbing after each shot was a waste of effort. I had/have to bow to his knowledge about such things as my sole experience with BP is C&B revolvers.
Black powder residue is effected by humidity
I grew up in New Mexico and often shot ten or twenty shots without a wipe
Then in California when in the navy did the same.
Then moving to Arkansas ran in to high humidity. Four or five shots the round would start getting too tight to load easily after four or five shots
Spit patch helped, but a ‘cake’ would form pretty quick
A few years ago I tried some speed shooting with paper cartridges, I got off loads on an average of eighteen seconds for ten shots. But even at the end the ball, wad combo got hard to run down, a .575 in a .62.
A wipe between shots prevented any hard loading for me.
It’s just easy. Ml is a slow-take-your-time sport
And twenty shots is a afternoon at the range for me
In October I was at an even, and was shooting smooth bore, and did load about ten shots before I swabed. It was pretty humid and shooting a bare ball I still had to push that ball down after five shots
Swabing between shots just cost you nothing and prevents ever having a load to tight to ram home.