?

I have a winchester air rifle, i dont remember the model but it is one of the good quality ones that shoot pellets. You break the barrel down to load it with a single pellet and close it to fire. It was a great little rifle, and fairly expensive but it was underwater for a while due to a flood. I want to try and repair it. Aside from a wd40 soak how can i clean the rust? The entire barrel is orange and scaled. I dont care about the blueing at this point. if i use a .17 brush can i get the barrel clean enough to fire straight again?