The quality of the gun drives the price more than the chamber length. If you buy a good make and model of gun in good condition and care for it by shooting the right size ammo and not needlessly modifying them you are ok.
I do not believe guns are investments, so don't count on making money. When sold from estates they are often sold at less than a premium, so it is important to educate your agent the best ways to sell for best money and the need for some paitence for price.
My course of action has been to reduce the number of guns I own and increase the quality. One day I will be at three or four good guns to pass on, but I am not there yet and probably never will be.
My son may or may not continue to hold on to my guns, his children (if there end up being any) who knows.
