Interesting 40% Silver Kenn. Halfs

Picked up 7 ea. of 40% half's today from the bank.
From the tellers tray of about 15 coins total.
I have found literally hundreds upon hundreds of these
at banks over the years. Normally I just look at the edges (reeding)
to pick them out. They are either all silver looking or silver with a light black/dark band. 3 out of the seven coins had very strong copper bands though. Never saw this before on 40%er's
They were 68 and 69 D's. For some reason I decided to look at the dates
and not just the edges before buying them. Glad I did as if I was just edge looking I would of seen them as just clads. H'mmm ?
Coins ring silver and are normal weight. Something new to me anyway
after all these years.