I would suggest that you remove the scope from the rifle and sale it by itself. You can always get more for a scope by itself than you will by leaving it on a rifle. Don't know right off what those rifles are going for these days. I would suggest you find out the price of a new rifle and drop your price below that by at least 20%.
The old saying is, "something is worth only what someone is willing to give for it" applies here. Start with a higher price than you would actually take for it. It makes a fellow feel good to jew you down some.