How do you sell your grandfathers old hunting rifles?

Answer 1

If there are a lot of them, it might be worth your while to buy a book that lists current firearm prices.
It will also give you pointers on determining a guns condition.
If there's not too many, you can research the prices by checking the selling prices at the on-line auctions.
(don't go by the asking prices, everybody on line is looking for a sucker)
Every firearm will have the manufacturers name, a model name or number, the caliber the gun is chambered for, and they'll probably (but not definitely) all have serial numbers.
Write all this information down, it will be important when you're doing your research.
You'll also need to make a determination on the condition of the gun.
Is the blue color worn off the metal? Is the metal rusted or pitted? Does the inside of the barrel look nice and shiny? What sort of shape is the wood in? Dents, cracks? What sort of shape is the finish in?
All of these factors determine the value of a gun.
If you get stuck on something, drop me a line on my message board here, I'll try and help.
(Click on my name, you'll access the message board thru my profile.)