It's interesting. Maybe a partial collar? Not sure how it would have got the reeded rim at the mint though. It won't fit in anything that would have gave it reeding... Edit: Nevermind, @Fred Weinberg explained it, lol.
He is correct that it is a partial collar, he was wrong about the reverse die being the hammer die. A partial collar spread out to the wider diameter because the planchet extends up out of the coining chamber and that only happens on the hammer die side. As you can see on your coin the wider diameter is on the obverse die side so the obverse was the hammer die. And I agree the "reeding" is damage most likely from a counting machine
ex-jewelry coin, was mounted, i have one too, thought was an error, but i made an error buying it for 12.00, lol have a great day, happy new years!!
The nickel is made from some pretty hard material. I find it hard to believe that the jewelry ring could apply enough pressure to make those edge marks.
This is the correct explanation along with Mr. Weinberg's earlier post. If you measure the diameter of the largest diameter, you should find that it's larger than the 21.21 mm (0.835") standard. It was not caused by a jewelry mount.
yuppers def dam, i had a cent5 with a ridg all around it and fred weinberg and potty set me straight, it sucks not winning sometimes, i feel for ya bro!!