Found a 1971 Half. Can someone tell me what is wrong with the rim? It sounds like clad when dropping it on the table. I need to find a better scale to weight it more exact.
I think it was put into something like this:
When these pennies are popped out they have a similar groove in the middle of the rim, and I've found about 3-4 similar halves.
I don't think it's a partial collar since there are reeds inside the groove. Also, there is a raised part on both sides of the groove. A partial collar is one-sided and only has reeds on the depressed side.
I believe it has been acid treated. (I've done this to coins.) The acid eats the softer copper core. This is why the coin also has a greenish-yellow color. The reeding on the copper section is not the same as the reeding on the cupronickel section. I do not think this is a mint error.