Kennedy Half Dollar On The Wrong Planchet

Simply amazing - I wonder if this was intentional

I suspect this was an intentional 'downsizing'. But first, accurate dimensions would be nice to have. A pic along side a dime would be cool.

Edge color is uniform, very thin and no indication of a core. Here's a reference for size and coloring. As for dimensions, what's the common measuring device for coins? I feel a micrometer would risk scratching the surface. Thanks for the input keep it coming.

This one isn't coming into focus. Thin planchet but strong strike. No distortion on the letters HALF. Weight doesn't match anything that should have been in the chamber either silver or clad. I am just not sure how you get to this end product.

Edge pics as requested. I dont know how so many of you take such amazing pictures.

the link datadragon provided has other KHDs struck on dime planchet, and to my surprise they seem about as well struck up as the example here, so I'm thinking not a fake

I am in the 'shed job' camp.
As we all know, .900 silver Dimes weigh 2.50 gms.
Weight information doesn't mean much in this case,
unless you can find an equivalent coin of exactly 2.072 gms., in .900 silver, and of plausible near equivalent diameter and thickness.

Authenticity check for wrong planchet:
Need to prove that this coin is not just a standard '64 Kennedy
1. I presume coin is .900 silver. This needs to be confirmed.
2. Need very accurate comparative thickness measurements with a ball tipped micrometer screw gauge
at exactly the same equivalent device locations of the coin in question vs a standard '64 Kennedy.
3. Micrometer measurements in at least two exactly equivalent clear field positions. vs a standard '64 Kennedy.

By the time the '64 .900 fine Kennedy's were struck, US Mint made very, very few wrong planchet mistakes with the silver (as opposed to base metal), coinage.
That is what makes it easy for me to be in the 'shed job' camp.

Ok, here is what I think. (if I can manage to sit in my chair without screaming out in pain from my back)

I think that this is an 'assisted error' created at the mint.
I think that somebody took a ball of soft silvery metal (like non-rosin core silver solder) that weighed 2.072g and placed it on a half dollar anvil die. they then activated the press and brought down the hammer die on this 'ball of metal'
it got squashed as the die came down, which would explain why the center is so well struck. it never reached the collar, so no reed formed. the pressure would keep pushing it down until it reached this final thickness, and it also explains no copper core. It would also explain the uneven rounded edge too.

just a theory.

Maybe you should get an XRF of this one too to see what metal was used.