Evidently there is a lot of interest in the old time way of doing things here which is encouraging. I have answered several PT's on this subject and will chance the post here for all. I am not needing another flame war. If you don't agree with the Old Colonel, that is cool. I don't want to hear about it. I have used his wisdom over the years with no hang fires or damp powder when hunting in the rain. It has always worked for me. Here goes:
Rubbing alcohol is a good degreaser for the barrel before loading. It also takes out any moisture form the barrel. I swab the barrel with a patch loaded with alcohol and while the alcohol soaked patch is in the barrel I bust about three caps on the nipple to drive any oil and moisture out into the patch. It should come out looking dry and charred on the end.
Run a dry patch down to make sure the alcohol is evaporated and the bore is completely dry. Now load as usual.
Fire your rifle and blow down the barrel or swab with a spit patch. The spit patch is not saturated but simply moist with saliva. Whatever you are comfortable with. Loading on a hot barrel is asking for trouble.
Load again and proceed.
For you flintlock shooters, wipe the flint, pan, and steel after each shot and inspect the flint edge for shiny metal build up or dull edge. Always clear the touch hole with a piece of wire the same size as the hole for 100% ignition.
I have heard in some circles that a flintlock rifle only goes off 80% of the time. Maybe it does for the guys who maintain their gun 80% of the time. If you maintain your weapon 100% of the time, you will get 100% ignition all of the time. I can not remember when I have had a misfire from a flintlock or a caplock. They go off as sure as any 30-30.
When hunting in the wet:
Use beeswax around the pan. After you prime, shut the steel down on the pan and put more beeswax around the joint where the steel and barrel mate. To seal up the bore after it is loaded, form a ball of beeswax slightly smaller than the RB and smash it on top of the ball with your ramrod. Carry the rifle muzzle down and the lock under you armpit. Warm and dry under there. Again, I have never had any misfires using this old man's recipe for success. Good luck and happy hunting!