I'm not anywhere near old enough to begin worrying about who to leave my stuff to including any excess ammo I may have on hand. If I were to go suddenly my wife has instructions to give a couple of my rifles and pistols to certain family and friends. As far as my muzzleloaders she knows to hand them over to the muzzleloading club I am chairman of, they will see that they are put to good use, noone else will really appreciate them the way the club would. I wouldn't want them relegated to adorning someone's mantel, they need to be shot.
If a guy has time to get rid of his stuff as some of them have they usually hire someone to sell their stuff as one of our old guys did, the guy turned a pretty decent profit and was paid a percentage of what he collected, the old boy had quite a nice collection, some went on Gunbroker.
It helps if your a member of a gun club, we have a table in our clubhouse that guys bring in stuff to be sold at reasonable prices, the money goes in the clubs coffers. Its always one of the first places I look when I go into the clubhouse, the other day there were as issued cans of WWII vintage bore cleaner with POISON in large letters, a buck a can, you never know what your gonna find. A guy can sell his stuff that way too, just put a price on it and your name.