I use the flip-up caps as well. I never worry about the synthetic stocks and I have them on all but one of my rifles. The only worry with wood that I have found is to be sure that the barrel channel in the stock is sealed with something. Many are just raw wood on the inside if the syock. If so rum a good water seal into the wood or use a good wax. I just dry everything off as soon as I get home and if need be, apply a little oil to the metal surefaces. I stick masking tape on my muzzle loader muzzle to keep out water or snow.

Snow has never been a concern with me . It has never done anything to the accuracy or to my gun stocks and I've been out when the snow's coming in hard . Clean your rifle / shotgun after use and you'll be fine . Blackpowder shooters may be more concerned about it . A major safety concern would be if the muzzle was shoved into the snow , where it could freeze and plug the barrel . The same precautions would be taken if the muzzle was shoved into soil . The only scoped rifle I have is a Marlin .22mag that I use for coyote. The scope has clear lens covers whick wipe off fine without touching the actual lens.

for the muzzle I use the cheapest sandwich bags wal-mart has and hold em in place w/ rubberbands or hair braid thingys from the wifes vanity. Just dont let her catch you.[]