Rim finning on open collar Bust Half

Can anyone explain why the rims on this open collar Bust half appear finned? It is in a straight graded PCGS holder. Thank you.
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Can anyone explain why the rims on this open collar Bust half appear finned? It is in a straight graded PCGS holder. Thank you.
Comments
"But seek ye first the kingdom of God and His righteousness and all these things shall be added unto you" Matthew 6:33. Young fellow suffering from Bust Half fever.
BHNC #AN-10
JRCS #1606
Maybe the edge was raised in the milling machine used at the time, and the dies were so worn that the extra metal wasn't forced into the recesses for the dentils, leaving the sharp edge?
Thank you. I suspected it was from the edge lettering process. I would like to hear other input.
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Here is a link to an NNP article by @BustDMs that explains the Castaing machine. (it opens a couple pages into article)
https://nnp.wustl.edu/library/book/568039?page=34
I can't speak to the OP coin.
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I looked through the coinfacts more images for 1836 and there are some with some limited rim areas. But I don't see anything like the OP. They have the deteriorated die strike details (missing dentils...). or some more off center appearance. Here is one but again not like the OP.
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https://www.pcgs.com/coinfacts/coin/1836-50c-lettered-edge/images/6169
https://youtube.com/watch?v=Yq4KA0mUnC8 - Dream On (Aerosmith cover) via Morgan James & Postmodern Jukebox
https://youtube.com/watch?v=m3lF2qEA2cw - Creep (Radiohead cover) via Haley Reinhart & Postmodern Jukebox
RLJ 1958 - 2023
Thanks for the input thus far. I added the reverse image to the first post. I've seen similar rims on other open collar strikes but this one is really pronounced. A member suggested the rims are damaged even though it's in a straight holder.
The die is slightly narrower than the planchet. What you are seeing is the outer edge of the planchet that wasn't struck by the die. You would expect this edge area to be slightly raised above the adjacent planchet area that was compressed by the die.
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
May have been netted. Certainly a strong XF. I believe the "finning" was imparted through the edge lettering process but I'm no expert. Thanks for all the input thus far!
