1971 D Strange Error Quarter

I do not want to contradict people who know more than me. But I would like to throw in my 2 cents on this one.

I am fairly acquainted with Dryer Coins:
https://goccf.com/t/143863

What puzzles me about this quarter is that on the Dryer Coins I have (only half shown in the pics), all of them have the rim built up so it curls up over the edge of the coin. I do not see this on the one in question - especially on the pic where Siamnbass shows the edge.

Even Dryer Coins that I have that have only been slightly tumbled have a ridge sticking up all around the rim.

I suppose the dryer-made rim could have somehow been taken off of his, but it also was done in a very uniform, and nice looking way.

Take a look at the look I posted to some of the quarters I have. As quarters tumble/roll, it seems the edge around the rim just gets higher and higher.

Something else is weird about the dryer quarters I posted. They do not have OBV and REV details wear on them like some of the other denomination Dryer Coins and the one Siamnbass posted. It is obvious the dyer quarters had to be in the machine for a long time since they are so thick. I am not sure why.

A thought just hit me... I bet your quarter is one one of those electrically altered/shrunken coins done by massive capacitor discharge?
http://teslamania.delete.org/frames...gallery.html

This likely explains the apparent uniform thickness from side to side.

Although in their gallery it shows "shrinkage marks" on the face of the coin, it might be, for whatever reason, yours does not have them. From the one gallery where they compare sizes of them made by increasing the power used, it seems you could backwards extrapolate the results and yours was made with less power - this might also explain the lack of shrinkage marks:






Just a thought

The uniform thickness of his is what sparked my memory about the shrunken coins.

Tumbling in a dryer cannot increase the thickness of the coin uniformly across the diameter. A Dryer Coin's center will retain the original thickness it had when it left the mint (or will actually have a loss of thickness due to wear - not a gain).

Although doing a bit more reading on the site where they shrink these, I see the shrunken examples posted all retain the milled edge.

His does not have a milled edge

Multi-step PMD?
...shrunk then the milling was removed?