I am studying the variable aspects of strikes among Morgan dollars and have found the term "coin turn." Since a VAM is a different characteristic, is a coin turn by an excess number of degrees a popular characteristic among collectors?
I'm not sure what you mean. Are you saying that the coin obverse and reverse are atypical? I think that's called a die rotation. The real intereting ones are off by half -- so I guess that would be 180 degrees. And yes! Those are pretty rare and often sought after.
I have found dozens of dimes that are off by 10 to 15 degrees and since I have found so many I cannot believe that those are rare.
If you found something ....could you post a picture?