Lots of good ideas here on storage and re-lubing.

I just wanted to re-iterate that I don't feel tumbling the rounds would be dangerous in the sense of altering the powder. The issue is debris getting embedded in the bullets and harming your bore. The same holds true if you drop a round on the ground, especially if it's dirt or SAND! Throw that round away, it's not worth trying to salvage a 3 cent round and damaging your bore.