The only thing I can think that would cause this is that the coin was double struck ? And if I remember correctly, the reverse is centered though.
Ok. I think I just realized whats going on here. The rim is put on the blank before its struck. Thats why it looks like its been double struck to me. Its just a slight offset.
Planchets are cut from a sheet of metal then rolled to dreate the rim. Then fed by mechanical fingers into the hub and stamped with the die. A slight misalignment gives the offset. Generally an offset needs a minimum of 5% to be considered an error, I believe. Minor ones are pretty common.
Just a few things to correct in this statement. Blanks are not cut from the sheet metal. They are punched. They aren't rolled, they go through an upset mill. And dies do not "stamp", they strike coins. As to your coin, it looks to be a misaligned die since the reverse is normal. Keep up the hunt!
