Whenever there is one of these threads that seems to always degenerate into the two opposing sides of the blowing down the barrel argument; I always reflect that humanity as a species would never have evolved to our current state if every muzzleloading shooter during the 16th, 17th, 18th, and 19th Centuries had stopped what they were doing to wipe the bore, rifled or smooth, after every shot.
When I got started in muzzleloading in 1971, blowing down the barrel was an accepted practice, and was mentioned in every piece of how-to literature written about muzzleloading. To include, The Gun Digest, The Lyman Black Powder Handbook, Muzzle Blasts magazine, Muzzleloader magazine, Outdoor Life magazine, Field and Stream magazine, the Herter's catalog, The Whole Earth Catalog, and others.
The reason it was mentioned virtually anytime a muzzleloading rifle was being talked about, was because shooters had come to the realization several hundred years previously that the hot, moist breath of a human, when introduced to the bore of a just fired muzzleloading rifle, or smoothbore, would serve to both keep the fired black powder fouling soft, but would also, because of the abundant moisture contained in expelled human breath, serve to extinguish any lingering sparks down at the breech plug's face/touch hole.
I blew down the barrel of three different flintlock longrifles over a span of 25 years, and not once during the thousands, upon thousands of times that I did so, was I ever in danger of harming myself. Not once.
That's because I knew with absolute certainty, that the rifle was empty each & every time that I blew down the barrel. Because, I had just finished firing that flintlock rifle. And, there was no way to be injured, other than possibly chipping a tooth on the barrel, which would be carelessness on my part. I certainly could not be shot, because the rifle's bore would be empty.
Of all the high risk activities that I have engaged in during my lifetime, I would have to put riding a motorcycle in traffic on an interstate highway to be at the top of my list as the most dangerous thing that I have ever done.
Far more dangerous than riding a bicycle in city traffic, which would be #2 on my list..
Ice climbing, rock climbing, mountain climbing, white water rafting, canoeing on rivers, mountain bicycle racing, road bicycle racing, logging, working as a machinist for 2.5 years, welding, forging, working on a farm, picking fruit off of tall ladders; all of the above things are inherently more dangerous than blowing down the barrel of an empty rifle that has just been fired.
I totally resent having other people take away my right to do as my muzzleloading predecessors have done for hundreds of years, in order to try, unsuccessfully in my opinion, to keep the idiots, the clumsy, the inattentive, the stupid, and the careless, who are constantly amongst us, safe from themselves.
You can't legislate competence, intelligence, or attentiveness.