1) IT IS Best to look into a copy of Phillip Peterson's Price guide. The Standard Catalog of Military Firearms: The collector's Price and Reference Guide. (9th edition, 2020, published by Gun Digest Books. Cost is around $28 + or - depending on where you purchase it. Both the current 9th or the 8th edition will provide an excellent guide. He provides retail value, most dealers offer 50% of retail when buying.
2) Look into the Master List of the Sold prices from Empire Arms, a reputable dealer. A year by year INDEX of sold items from 2020 down to 2013 is provided. It provides a photo mosaic of the firearm, its description, and the SOLD PRICE. This is what a person paid. These are pretty good prices that I find fair to great deals. A more realistic value guide for the midwest.
https://www.empirearms.com/newstuff.htmIndex of "New Stuff" page over the years
Note: these items are NOT currently for sale
EMPIRE ARMS has published many hundreds of "New Stuff" pages containing many tens of thousands of collectible military firearms over the past several decades. Until now there has been no way to browse through these past pages to see the great variety of items that we have offered for sale via this unique venue. We think it serves a purpose to show WHAT we have sold and HOW MUCH we actually obtained for them.
3) Search Gun Broker Auction Site. GunBroker.com is the world's largest online auction site for firearms and hunting/shooting accessories in the US. A similar firearm may be offered. Prices are sometimes way out of line. Some sellers start prices at just crazy values fishing for a high roller or fool. This is the worst choice. But you can see what some sellers are asking as a starting price.
4) Look into some old auction catalogs from the big auction houses. These offer generally high end rare items. Peterson's book will help tell you if it's a rare piece. Or ask the old guys that always attend auctions or guns shows, both buyers or sellers that are friends or neighbors.
5) Bring the Item to a Gun Show and see what you are offered by dealers, sellers, or people attending the show. You do not have to sell, just walk around and get offers. It can give you an idea of what people will offer. Get phone numbers, then do research. Or do you research ahead of time( have an idea of book value), then you will know a fair offer when you get one from someone at the show and can sell it ASAP. Always get the buyers name on the DL: also the phone number and address. The buyer most likely will want your information. Some have the buyer sign a statement saying he or she is not a felon, has no domestic dispute restrictions, and can legally buy the firearm. If the buyer is not willing to provide at least his DL & info --- RED FLAG. Best not to sell to that individual as a private sale.
6) Call a gun shop or big store like Cabelas they will come over and make you an offer, you can see what the offered price is if you want to dump a collection fast and safe. Remember they have to make a profit and sometimes do not sell at retail, so their offer may be considerably less than book value- say 25-60% less. A 25% loss is fair, the antique shop in our town has a 40% reduction of what an antique might sell on eBay. Since he is not an FFL he does not buy firearms. Most antique shops avoid guns unless they are vintage BB, or pellet firearms. Most large flee markets near urban areas also ban firearms, explosives, fireworks, and ammunition. Some of the small town markets do not.
You best bet is #1 or #2, or ask on a forum for opinions. Provide photos of the firearm so the readers can see what it is. Prices are dependent of many factors: rarity of the firearm, condition- condition-condition, repairs, special markings, bore condition, and a matching parts. Regional differences also play a big factor, as well as local firearm laws. Prices can vary greatly at the type of gun show, or auction. Price depends on if its sold to a dealer or gun shop; they have to make money for overhead. Auction houses charge a fee as much as 35-40%. Private sales or trades can sometime fetch the best value. Family sold items at a gun show may get market value or slightly less depending on the seller/buyer. Most buyers want to pay between retail and what a dealer would offer unless it is a fantastic rare piece. Then it may go higher than book retail. Certain guns are in demand, others will never go for book price. Some have topped out in price, few want to pay as much as the book indicates. Like any antique when you buy it, its worth big bucks, but items, styles, & tastes fall out of fashion. Hence, when you sell it, its talked about as if junk. People want to pay as little as possible. Some use unwanted firearms as barter for repairs or trades.
The rarity, condition, and originality are a key factors in firearm prices. Most firearms are worth value just for their parts, if the parts remain in original condition. Price is also dependent on what the buyer is actually willing to pay, what cash they have in the pocket, and how bad he or she wants an item. Sometimes the seller just wants to dump a non wanted collection for at least what the collector paid and cover the table fee, lodging, and food bill for the weekend in order to get rid of unwanted collections. As a buyer you generally cannot expect the seller to take less than they paid when it comes to firearms. Antiques are a totally different animal; stuff purchased 20 years ago may have fallen out of fashion and you are going to take a loss if there are few buyers that want items. Different age groups buy & collect different items. At the local antique shop items like dark vintage furniture, glassware, pewter, beanie babies have fallen out of fashion. Value has tumbled. Unlike antiques, firearms have generally increased in value or at least remained stagnate in price. Most pistols or rifles are worth some value just as parts sources. Some buy guns to breakdown just to sell the parts. So the real value is an elusive figure