Counterfeit Half Dollar 1962?

The problem is the weight - only about half of a genuine silver half.

After enlarging and enhancing the edge pic, it kinda looks to me like I see a circumferential line. Could this be an Aluminum casting? If you have access to a SEM at a local university (or even a Precious Metal Analyzer at a local pawn shop), that might help us get closer to an answer.

there is just something "off" about the coin - cant quite put my finger on it.

to me it doesn't look real

The entire 1952 image looks slightly rotated clockwise, can't really use that as a direct comparison for "leaning forward". Visually, the 1962 looks genuine to me. What we're missing is a caliper measurement of the thickness or, more easily, a visual side-by-side of the edge with a genuine piece.

The sound test is not proof-positive to me, and I'd otherwise lean towards "the reverse has been planed off" except that nearly half would have to be removed to make this weight and it would then there would be an obvious difference in the thickness. I'm stumped.

Here some photos to compare it to a normal half dollar (it is a 1966 Kennedy, I don't have in this moment a FranKlin to compare):

Could be more interesting than a genuine piece ; the master hub for 1960-63 Franklins was reworked after years of gradual deterioration. This looks like a pre-59 Benjamin with hand engraved date (the numerals are improperly shaped) and typical cast copy legends. Perhaps it is uniface as the fakers didn't have a reverse ready - a rare uniface counterfeit die trial/pattern struck in white metal - much more entertaining than a genuine circulated 1962 Half ... thanks for sharing.

It took some time and effort to destroy that coin.

It may be over laid on the kennedy but not sure