CHACE: This prospecting for copper - one old penny at a time - there are thousands of people doing this. This is the thing, Steve Wardak is what's known as a coin roll hunter. The coin roll hunters, they like to go online and show off their hauls.

UNIDENTIFIED MAN #1: Well, guys. I did it again. I had to go and pick up another box, $25 worth of penny rolls.

CHACE: There are dozens of these.

UNIDENTIFIED MAN #2: These are all pre-1982 copper pennies. See?

CHACE: Some people have special machines that sort out the pre-1982s out from the post-1982s.

WARDAK: I can turn it on for a second to show you how fast it goes.

(SOUNDBITE OF MACHINERY)

WARDAK: These are all copper...

CHACE: Steve doesn't have a machine 'cause he likes to sort by hand. He gets the coins and he brings them home to his fiancé. And this is kind of the thing they do together at night. They sit next to each other in the living room and go through them.

WARDAK: Just get going. Like, I'll give her a box and I'll take my own box - '82, there's '82.

(SOUNDBITE OF PENNIES)

CHACE: You actually get lucky really quickly. Almost a third of the pennies Steve is pulling out are 1982 or before.

WARDAK: These are the copper pennies. You can tell the difference in sound.

(SOUNDBITE OF COPPER PENNIES)

WARDAK: And these are the zinc pennies that they make now...

(SOUNDBITE OF ZINC PENNIES)

WARDAK: Sounds completely different. It sounds like fake money.

CHACE: Kind of subtle to the untrained ear. Listen for the base. Copper...

(SOUNDBITE OF COPPER PENNIES)

CHACE: Zinc...

(SOUNDBITE OF ZINC PENNIES)

CHACE: Steve has collected $475 in old pennies. He figures the copper is worth double the face value, so that's a thousand dollars, practically, stacked in boxes in the back of his closet.

(SOUNDBITE OF PENNIES)

WARDAK: Eighty two...

CHACE: You know, there is this problem with this investment strategy which is, right now, it is illegal to melt these pennies down. The copper in these pennies is stuck there. Unless - and this is what these guys are hoping for - the U.S. government kills off the penny, then the pennies are no longer U.S. currency. You can scrap them, melt them down.

If you turned on the computer right now and you saw that they'd abolished the penny, what would you do?

(LAUGHTER)

WARDAK: I would probably go buy as many boxes as I could afford.

To listen to the complete story, or read the transcript, see:Penny Hoarders Hope For The Day The Penny Dies(www.npr.org/2014/05/21/314607045/penny-hoarders-hope-for-the-day-the-penny-dies)