All
I typically don't hunt in the shower, so it might be a moot point for me... I did leave mine out overnight on my covered patio while it was raining and high humidity... The next day I shot it just before noon with no problems.
As for ballistically speaking I do not have a chronograph, but will probaly buy one in the next couple of months... Accuracy does not seem to be different between the two powders and the velocity might be able to be increased by adding slightly more AP.
My testing with AP was done outside in a day-long light rain & at our hunting cabin last fall. Poster Cayugad here can verify the testing because I have mentioned it a few times before. The bathroom test actually involved three rifles... the 3rd was a Black Diamond with Pyrodex pellets... which fired also.
Nobody leaves their loaded muzzleloader outside in an overnight rain & plenty of AP shooters will tell you you need around 20 grains more AP to reach 777 velocities with only 100 grains. Goodbye newguy... I heard enough bull from one poster. I'll try to stay clear of you in future replies & threads.