Underweight 1980 half dollar

I was going through a few rolls of half dollars looking for the '82 no-
FG ones, tossing coins into a pile. One of them, a 1980, made an off
sound versus the regular sound the halves usually make. I picked it up
and it felt a little lighter, if that is perceptible. Anyway, weighing
it proved it weighed 9.5 grams versus the average ~ 11.5 gram weight
they are supposed to have. It is not a magician's coin either as far
as I can tell, so not hollowed out and false reverse filled. No, a
bounce on the table makes a solid sound like a coin should. Did the
mint use different alloys in 1980 briefly? My only guess is that
either the metal is different or it has a hollow air bubble inside.

On Oct 22, 12:49*am, HeeHawkeye wrote:
I was going through a few rolls of half dollars looking for the '82 no-
FG ones, tossing coins into a pile. One of them, *a 1980, made an off
sound versus the regular sound the halves usually make. I picked it up
and it felt a little lighter, if that is perceptible. Anyway, weighing
it proved it weighed 9.5 grams versus the average ~ 11.5 gram weight
they are supposed to have. *It is not a magician's coin either as far
as I can tell, so not hollowed out and false reverse filled. No, a
bounce on the table makes a solid sound like a coin should. Did the
mint use different alloys in 1980 briefly? My only guess is that
either the metal is different or it has a hollow air *bubble inside.


I might add that the thickness looks slightly thinner on this 1980 vs.
other coins from that era. Maybe it was a thinner planchet that was
used?

"HeeHawkeye" wrote:

I might add that the thickness looks slightly thinner on this 1980 vs.
other coins from that era. Maybe it was a thinner planchet that was
used?

Sounds like a "wrong stock" error, although I think the weight is a
bit high for it to have been struck on quarter stock.

--
Mike Benveniste -- (Clarification Required)
Its name is Public opinion. It is held in reverence. It settles
everything. Some think it is the voice of God. -- Mark Twain

"HeeHawkeye" wrote in message
...
On Oct 22, 12:49 am, HeeHawkeye wrote:
I was going through a few rolls of half dollars looking for the '82 no-
FG ones, tossing coins into a pile. One of them, a 1980, made an off
sound versus the regular sound the halves usually make. I picked it up
and it felt a little lighter, if that is perceptible. Anyway, weighing
it proved it weighed 9.5 grams versus the average ~ 11.5 gram weight
they are supposed to have. It is not a magician's coin either as far
as I can tell, so not hollowed out and false reverse filled. No, a
bounce on the table makes a solid sound like a coin should. Did the
mint use different alloys in 1980 briefly? My only guess is that
either the metal is different or it has a hollow air bubble inside.


I might add that the thickness looks slightly thinner on this 1980 vs.
other coins from that era. Maybe it was a thinner planchet that was
used?

Does it have all 3 clad layers? Possibly delaminated before being struck?