RE: What's the best all-weather rifle?
Nearly any bolt action or single action rifle will work, as they are the easiest to clean. Synthetic stocks are typically the most durable, followed by laminates. Wood stocks are more susceptible to moisture and temperature changes.
Good routine maintenance will keep the metal in good shape. If you are out inharsh weather, make sure to clean and oil all metal surfaces when you get back home. This goes for bothblued and stainless rifles.