You can visit some of the online firearms auctions/classifieds like GunsInternational.com, FirearmsLocator.com, Gunbroker.com or AuctionArms.com and see what similar guns are being offered/selling for.
The library may have a copy of Gun Traders Guide, or the Blue Book of Gun Values, but it will likely be out of date. A more current means of establishing worth of everyday guns may be to check the on line gun auction sites, such as gunbroker, auctionarms, and gunsamerica. Search for the make and model of your gun, and specify CLOSED auctions. Look at the prices they actually sold for, not the high reserves with no bids.
you can check the auction sites to see what they are selling for.
On line auctions
Blue Book of Gun Values
BLue book of gun values
You will have to specify which firearm you are interested in.
Gun Broker, Auction Arms, American Arms
Blue Book of Gun Values is one.
Blue Book of Gun Values, you can look for comparables on Gun Broker, Auction Arms, Guns America..
Internet, gun show, gun shop, Blue Book of Gun Values, Standard Dictionary of Firearms
You can pay for a subscription to the Blue Book Of Gun Values online and they can be reached at bluebookinc.com. Alternatively, you can visit some of the online firearms auctions/classifieds like FirearmsLocator.com, Gunbroker.com or AuctionArms.com and see what similar guns are being offered/selling for. Or you can go to www.firearmspriceguide.com, the FREE online price guide to firearms.
Blue Book of Gun Values
The Blue Book of Gun Values is copyrighted, and not available free on line. Your library may have a copy you can check out, but it gets updated each year.
On line firearm auction sites, such as gunbroker, auctionarms, and gunsamerica may represent the best estimate of what a given gun is selling for, if you search for your gun in the closed or completed auctions.