If the rust on the action isn't too bad you can use plain gun oil and steel wool to scrub it off. But if it were mine I would remove the stock and soak the breech end in a bucket of kerosene for a day or two. Don't laugh. I did that with a Remington 700 I bought used and the previous owner didn't take care of. The trigger was so rusty that it felt like 2 bricks rubbing together. 3 days of the soak and scrubbed with a toothbrush, degreased and lightly oiled and it was as good as new. (And by the way - it was the wife's toothbrush)
And yes Ballistol is a great rust preventative.