Howdy
Regarding the information about trying to get a better seal in a rifle and how it affects ammo in a revolver.
In my opinion, and it is of course just my opinion, going to the extra effort to get a good seal in the chambers of a revolver is a waste of effort.
Let's look at it objectively for a moment. A rifle is basically a closed system. Once the breech is closed, it is just a big long tube. All the fouling goes straight down the barrel. No amount of sealing the case in the chamber is going to eliminate all that fouling in the barrel. The only fouling that goes the wrong way is the stuff that leaks past the cartridge case and gets past the bolt and into the action. Once fouling gets past the case, the openings into the action are great big gaping holes, and fouling can build up all over the cartridge lifter or carrier, depending on the design. It also can work its way into the guts of the action and get onto the linkage that actually operates the rifle. So because of this, it behooves the BP rifle shooter to keep the fouling in the barrel as much as possible, and the best way to do that is to seal the case in the chamber.
Revolvers, on the other hand are not closed systems. There is the barrel/cylinder gap, and fouling regularly blasts out of the gap and gets all over the front of the frame and the cylinder. Nothing you can do about that, it is the nature of a revolver. At the rear of the cylinder, where the case butts up against the recoil shield, a revolver does not seal the breech anywhere near as tightly as a rifle does. There is always a few thousandths of an inch of free play where the rims sit. A revolver has to be designed that way. If the rims were tight against the recoil shield, the cylinder would not turn. Now I suppose some fouling can be kept off the rear of the frame by attempting to obturate the case as well as possible in the chamber, but you are still going to get fouling blasted all over the front of the cylinder and frame, from the barrel/cylinde gap, no matter what.
Now lets look at the frame of the revolver. There are only two small openings in the frame of a Single Action revolver that will allow fouling to get down inside the works of a revolver. The window in the recoil shield where the hand pokes through, and the window at the bottom of the frame where the bolt pokes up into the cylinder. That's it, just two very small openings, and they are mostly plugged up by the parts that are sticking through them. Not like the gaping openings in a rifle that offer no resistance at all to invading fouling. Yes, there is the slot the trigger moves in, and the big slot the hammer rotates in, but they are not located in a place where fouling will be blasted directly into the lockwork like those two small openings are.
My point is, with a revolver, if you go to the extra effort, annealing, neck sizing, whatever, to make the case seal better in the chamber, you're just kidding yourself. The fouling will go right out the gap, but very little will get down inside the lockwork where it matters anyway.
Keeping a revolver well lubed and running well is a different matter. That requires plenty of BP friendly lube. But it is not a sealing issue.
I shoot BP in all my CAS guns. I shoot 44-40 in my rifles, because it seals the best in a rifle chamber. My brass pops out almost as clean as smokeless brass and almost no fouling at all gets into the action. But I shoot 45 Colt in all my revolvers. I make no extra effort to get the cases to seal. No Lee Factory Crimp, no annealing, no neck sizing. Just a case full of FFg and a 250 grain Big Lube bullet. My guns revovlers run all day with absolutely no attention, 6 stages, 8 stages, 10 stages. If it is a 2 day shoot, I don't clean them in between days, just start shooting them the next day. Because of the big lube bullets, full of SPG they just keep shooting. Because of those little tiny frame openings, very little fouling gets down inside the action.