This season my gun was loaded for 5 weeks, some days it drizzled a bit some days there was a light rain for periods, at days end I would wipe down the outside of the barrel after first removing the lock, wipng the inlet and barrel near vent with a dry rag, and sticking feather in vent then wiping barrel with wd40 rag and runing a lightly oiled patch down barrel to ball followed by dry patch, then the wood got a good wipe down with dry rags, furniture gets the same as the outside of barrel, I have used this rountine for several tears and have yet to have a pfffft boom or wores yet a pfffffffft no boom, I usually put the gun in my gun room till the next day, this room is not as cold as outside but not as warm as the rest of the house, I have kept a gun loaded for up to 7weeks and it still fired, if I really get drenched I will shoot the gun and start from scratch, I have never put tape over the muzzle or a dam of wax on the barrel at the lock, I do use cowsknee at times but generaly keep the lock tucked under the sleeve/cape of my shirt, I suspect many missfires whether the gun has been unloaded or not are a result of not getting a complete cleaning and drying from the begining, or carrying the gun in a fashion that allows moisture to get where it don't belong, just my thoughts on the subject from the soggy Pacific N.W.