I'd agree with KCE -- from what I've been reading the past month or two, silver hasn't peaked (and most likely won't for some months), so I'd hold for a little while yet. Otherwise, this is the first time I started detecting 20 years ago that those worn, non-key silvers we do dig are worth beyond face value -- making metal detecting a geeky hobby
that can actually pay off for once **if you do your research to know where to hunt and beat the bushes hard** for silver and gold because it's melt value is really high now. (And no, it's not against the law to melt silver coins. That's a fallacy. It's only against the law to deface coins to try to increase their face value.)
Still, a reminder before you count your $$$ chickens with all those worn-down Mercs and SLQs you might find: Depending on date and type, US coins are not 100% silver (usually 90%) and the refineries you use (NEVER NEVER go to jewelry shops or cash-for-gold joints) may have a very small percentage tacked on (consider it "handling," for lack of a better term). So if you have, say, 8oz of worn-down Merc dimes, you only have 7.2 oz of retrievable silver. Same thing with gold coins and rings.
As much as I like a good park or playlot, I'm spending my spring and summer pounding the dirt for gold and silver. All in all, it's a good time to be a geek.