A Numismatic News reader from Mississippi submitted an interesting Kennedy half dollar find. While searching through circulated rolls he found a 1971-D struck on a planchet of quarter-dollar thickness or what is called a “Wrong Stock” error. It weighs 8.8 grams versus the normal 11.34 grams for a clad half.
In this case, the Mint actually punched half dollar diameter blanks from a coil of clad strip that was intended for quarters. In general, wrong stock errors are not common, but when they do occur because of the nature of the error where many blanks can be punched out in short order, many can get out unless caught early and suspect batches of blanks scrapped.
The most common of the wrong-stock errors are the 1970-D quarters struck on dime stock planchets. Tens of thousands of these got out that year and still get found in circulation from time to time. They are most often found when they are rejected by a vending machine or coin counting machine.
Wrong stock errors struck on planchets that are thicker than normal are typically well struck while those struck on thinner than normal planchets are usually weakly struck, particularly on the lettering around the rims as we see on the example shown here.
None of the wrong-stock half dollars are particularly common but the 1971-D on quarter stock is the most frequently encountered according to CONECA president, Mike Diamond. He figures uncirculated examples to be worth about $150.
Back in June I reported upon a collector finding a 1980-P Kennedy half dollar struck on a Susan B. Anthony planchet. Since then I have had a report of another being found by Combined Organizations of Numismatic Error Collectors of America member Ken Glickman in October. The story of his find can be seen on the CONECA Web site at www.conecaonline.org.
I suggest that collectors keep checking those halves and let me know what you find.