Howdy
You are trying to solve a problem that does not exist.
Shooting Black Powder in cartridges is complicated enough, there is no need to make it more complicated.
I have been loading Black Powder into cartridges for close to 20 years.
I have loaded thousands of rounds in all those years. I don't know how many thousands, let's just leave it at thousands.
45-70, 45 Colt, 45 Schofield, 44-40, 44 Russian, and 38-40.
Sorry for the mess, but here is a snapshot of a corner of my loading bench with hundreds of cases cleaned and ready to be loaded. Look down inside them and every one has a light coating of black powdery soot inside. Missing from the photo are 45-70 and 38-40, but I assure you they have the same light coating of powdery soot inside. I don't know how many times each of those cases has been reloaded, probably at least a dozen times.
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Notice I said 'cleaned and ready to be loaded'. I did not say 'shiny'. It has been my experience that shiny brass does not shoot any better than stained brass. It is just easier to find in the grass.
All my Black Powder brass is stained on the outside. If I wanted to get it shiny on the outside I would polish with steel pins, but there is no need.
Cleaning brass that has been fired with Black Powder is simple, there is no need to make it more complicated. At the end of a match, all my brass gets dumped into a jug of water that has a squirt of dish soap added. There is no need to obsess on how quickly to dump the brass in the jug, the end of the match is plenty of time. However if you wait 24 hours the brass will develop a coating of green verdigris, and then you might as well throw them away.
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Next step is to rinse the brass. You will hear all kinds of baloney about 'neutralizing' the acid or base in the Black Powder fouling. Chemically speaking, I am not neutralizing anything, I am diluting and washing away the fouling inside and outside the cases, nothing more and nothing less. This is the most important part. I rinse the brass probably about six times or so. I have a kitchen sieve that I use to dump the brass into, then I dump out the dirty water and fill the jug with warm water. The water does not have to be super hot, but warm helps dislodge the fouling from the brass. Dump the brass back into the jug with clean warm water, close the lid and shake it good to help dislodge the fouling. Do this until the rinse water runs clear, maybe a half dozen times or so.
Then I lay out the wet brass onto cookie sheets lined with paper towels. I used to dry the brass in an oven heated to well below the boiling point of water, but now I don't bother anymore, I just let the brass air dry for a couple of days.
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Next into the tumbler. I use Lizzard Litter in my tumbler, which is the same as the crushed walnut shells you buy for polishing brass, but it is much cheaper. Available at big box pet stores.
Some guys add stuff to the tumbler to polish the brass further, I don't bother. Did I mention that stained brass shoots just as good as shiny brass?
That's it, my brass is now ready to reload. The small amount of powdery soot inside the case does not matter at all. The bits of crushed walnut do not migrate down into the case and scrub very well, but did I mention it does not matter? Been doing it this way for a long, long time.
A couple of more things. You will read where a lot of guys pop out the primer and clean the primer pocket with a primer pocket brush. Either before or after the rinse. Another thing I haven't done in years. Yes, there will be a tiny deposit of black goo at the base of the primer pocket, and over time it can build up enough to cushion the blow of the firing pin. Again, I have not bothered to clean primer pockets in years. I load most of my BP ammo on a progressive press and there is no provision for taking the cases off and cleaning the primer pockets between decapping and seating a new primer. When I sit down to load Black Powder ammo, I usually load a few hundred at a time. I ain't gonna spend time scrubbing out primer pockets. I cannot recall having a primer fail to pop in all those years.
Annealing: Sorry, but that is another waste of time. At least as far as the pressures involved with Black Powder cartridges are concerned. I lose far more brass to being stepped on and crushed than getting split. Every once in a while a 44-40 case will develop a small split at the case mouth. That is because 44-40 brass is so thin at the neck. If the split is less than about 1/16" long I go right ahead and reload it again. If the split is more than 1/16" long I file that case in the circular file. I can't remember the last time I had to throw away a split 44-40 case. All my other BP cartridges never develop splits.
One other thing. Do try to rinse out your brass in a reasonable time. In case you have not noticed, I am basically lazy. One time I left some brass sitting in the rinse jar for a whole bunch of months before rinsing it. When I went to load it again I noticed the powder level was coming up a bit higher in the brass than I was used to. Unfortunately the fouling down inside had formed a meniscus down at the bottom of the case over time and it did not get removed when the brass was polished. I wound up throwing that batch of brass away. So be sure to rinse your brass out within a week or so of shooting it.
Here is a shot of a bunch of 44 Russians being reloaded. Not very shiny are they? And there is a little 'patina' of soot down inside each one.
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