the rain is my favorite time to hunt. but as for my guns inthe rain. i have a synthetic stock 30-06 that i take in the rain so that my wood stocks don' t swell. i take either a towel or something to cover up the bolt and scope. i just bought me one of those umberellas but i don' t think i will ever use that thing. looks like too much work to set up.
i just cover up my impertant parts and when i get home i dry it all out and put it away for next time. some of that air in a can works real good for getting the moisture out of the chamber and bolt area.
works for my stuff but i sure others have better ways