I use the usual,
I put together coin collections, Works for buying and dumping.
Poker, its more fun to push around big coins.
When they try to charge me and its a small bank I just say its for my kid to put together a coin collection, Gets em every time. But can only be used a couple times at off branches.
If I am traveling on vacation sometimes I say its for a fund raiser, they dont have to know its for my funds.
Since some of them know I am a jeweler, I jsut say, ever heard of the rapper 50cent? and leave it there.
When dumping sometimes when they ask where did you get these? I just say..."I have a tenant that is a real ass hole!"
They pity me at that point.
OF course some of them know exactly what I am doing and think I am crazy...oh well, its amazing how many of these tellers have stories about people who bring in silver and say that you can still find it but "not like you used too" and they also seem to think its a rare thing. But you look at the volume of change they deal with and they only crack a few rolls, we crack hundreds, its just scaling it up.
Over all the less mention of silver the better, it seems that bothers people, but coin collecting is ok. When they ask if you find it just say once and a while but not often.