So, prefacing this by saying I've seen a few errors on 1oz. silver rounds in the past. Two were off-center strikes (one of which was actually slabbed by ANACS) and the third was a pretty clear planchet clip. 
I bought this particular round because it had a small clip on the edge. I was looking at it a little closer last night, weeks after the purchase, when I noticed doubling. It's very obvious under magnification and to be honest I'm embarrassed I didn't notice it when I actually bought the coin. 
I thought it might be strike doubling at first, but nothing is flat and it's consistent across the entire bell. 

I'm not sure where else to post this because it's not technically a US Coin, a World coin, a token, etc. I'm curious to hear your thoughts.