Most dwellings are warm enough to quickly dry the barrels and if one is concerned, a bit of gently warming with a hair dryer would solve the problem. My guns do not have any gaps at the muzzle or loose ribs and I've not had a problem with rust. Keith is correct on hunting in rainy conditions. I keep a towel to wipe dry my guns and carry on. If they get really wet, I just remove the locks or bottom plate on a box lock gun and let them dry. Lightly oil and reassemble.