If you're asking for a valuation you'll want to make a post in the appraisals section here. You'll want to take some photos of your own of everything you'll be looking to sell and be as specific as you can about everything you're looking to sell. The less specific you are, the harder it is to give an accurate valuation.
Once you've had an appraisal if you wish to list it read the forum classifeds rules which can be found here.
Then, once you've figured out your price you'll want to list in the 'spring rifles' classifieds section which can be found here.