I pulled a half that looks like silver but it's a 1976. Looks 40% too. Does that exist? It's pretty dirty which may make the appearance warped.
It's so corroded that I couldn't see the mint mark. I took a photo and zoomed in. It's a D. Now I am thinking it's copper clad that turned a silver color somehow.
Check this out, there are 1976 D silvers! I have two https://www.goldeneaglecoin.com/item/kennedy-half-dollar-1976_d-bu?gclid=CLDz_aqUlc8CFQSPaQodtU8J4g
On a related note, I got my 76S 40% BU for my album yesterday. And a 79S type 2. Purchased, not found.