When leaving it loaded I like to seal the barrel and nipple off. Some simple black electrical tape over the muzzle, which can be left on and won't effect accuracy when shot, and then I put a foam earplug over the nipple and set the hammer down on it. Last year I left it loaded for over 3 months like this and it went off fine and hit POA when I emptied it (real black powder). I do live in a pretty low humidity area though.
It is also good to do something like this to signal that the gun is loaded. I've actually been using either electrician's red phase tape (basically same as black electrical tape) or some red adhesive TC stickers that I found at a local Sportsman's Warehouse made just for taping over the end of the barrel. The red tape over the bore and the yellow foam earplug signal to me that the gun is loaded, and my family also knows that it means it's loaded.
It is also good to do something like this to signal that the gun is loaded. I've actually been using either electrician's red phase tape (basically same as black electrical tape) or some red adhesive TC stickers that I found at a local Sportsman's Warehouse made just for taping over the end of the barrel. The red tape over the bore and the yellow foam earplug signal to me that the gun is loaded, and my family also knows that it means it's loaded.