Breechplug,
I started hunting with a muzzleloader in 1978, it was a .45 H&A Underhammer, I still have the action and it is now a .58. I rebarreled it myself. in 98
No I have never had to worry about my Guns going Bang even in the pouring rain, I used all kinds of nipple protectors. I have hunted in the pouring rain, did so this year with the Rolling Block.
I have hunted with my own cast Balls and Boolitze in ML since 78 also. I now cast a very efficient 333 gr LFN that shoots well.
I haven't carried any of my large selection of Center fires hunting since 98, took a Antelope in WY with my 58 Underhammer at over 150 yards with a RB.
I drifted to inlines in 2003, and to Smokeless in 2008.
I built my own Smokeless gun and Killed three deer with this last season including this 8 Pt in the wet rainy snow. It was the last weekend of regular season do you remember the rain.
This is a Nice Doe I took, it was snowing hard when I harvested it, the White specs are snow flakes in the air.
These are less than perfect Photos from my Phone.