If you have not shot the rifle and do not want to unload it, take the finger cot off. Put a piece of cotton fabric on the floor, and store the rifle muzzle end down. That way if any moisture does form, it will run away from the powder charge and move down the barrel onto the cotton cloth.

Before you head out in the morning take a dry patch and swab the barrel down to the projectile and then replace the finger cot. Also try to keep the rifle stored over night in the same temps you were hunting in, but in a dry place. Wipe the outside of the rifle off from all the moisture and finger prints that might have formed.