So it is struck thru.
But not a rim burr tho.
As if it were a rim burr extra metal of the rim the place it came from would be copper plated as the rim burr is apparent when the blank is still zinc.
If you try and find on this coin you lll see a piece of the rim gone and zinc. So not a rim burr but a defective part of the proto rim and when it enters the striking chamber it gets knicked off and struck thru.
Hopefully that makes sense but I'll say it again lol
The rim burr if it was that the piece missing on the rim would be plated copper as the rim burr is extra metal when the blank is zinc and not yet coated with copper