1972-S Kennedy Half
Obverse Die Break
NGC PF 69⭑ CAMEO
Although die breaks that result in cuds are not rare, they are in proof and especially in larger denomination. This proof Kennedy Half has a huge cud and is one of the largest known.
Proof coins are struck by technicians who hand feed the blanks into special presses. They are produced, examined and packaged using extreme quality control. It is very unusual to find major proof errors. A few broadstrikes, off-centers, double strikes (in collar) and off-metals have been known to be found in sealed proof sets. Proof errors are aggressively sought after by many error collectors.
Proof Errors are featured in chapter 21 of my
NLG Award winning book, World's Greatest Mint Errors:
