Tell your friend to go to Barnes and Noble and look it up in the Guntraders book. They have 2-3 different books with gun values and articles on how to determine the condition of your gun. It is very helpful! That way you can take the average of the 2-3 books and determine the market value.

Have him take the rifle to a gun show to sell. Try to sell it to a private citizen, not a gun shop owner. You'll get more for it there than if he takes it to a gun shop.

Matt