As I was reading a post from 71Avilon about rim burrs it dawned on me to see what you all think if this could be one
I would need to see the 3rd side at 10 and 2. Maybe a shim for a diner/bar top table. I lean towards PMD.
It could be a faulty planchet. But I wouldn't consider it a Rim Burr. I've seen a weirder issue. From my collection on a copper plated zinc blank..
According to Error Trends Magazine it was damaged in the upset mill. That's the stage where the Rim is raised