I read an article last summer that discussed the popularity of the then new 1964 Kennedy half, to the extent they stated demand was so high, the 1964s we're minted through 1966. Anyone heard this before? It would seem this would've created more opportunity for transitional errors. Mike
Hopeful that issuing more 1964-dated coins would counter the speculation in them, the Treasury requested and received Congressional authorization to continue striking 1964-dated coins into 1965..........
Here's an article that explains the details https://www.ngccoin.com/news/article/711/ Transitional planchet errors are known and people have posted pics (here or the PGCS forum) of 1964 dimes struck on clad planchets as well as 1965 or 1966 dimes on silver planchets, so there is a possibility that all the combinations of denominations and compositions can exist. It may be lottery odds of finding one, but if you want to look, knock your socks off.
Yep, that's the article! I do some coin roll hunting and have branched out from just pulling the silver, to looking for other interesting finds.