Ron Guth:
The 1877-S Half Dollar is a great date for collectors because it sports a large mintage of over 5.3 million coins, it is readily available in most grades, and it is affordable in Mint State. Hundreds have been graded in MS62, MS63, and MS64, and scores have been graded in MS65 and MS66. In MS67, this date is exceedingly rare (see the PCGS CoinFacts Condition Census above). Most 1877-S Half Dollars were struck very well, though the rare example will show weakness on the star on the right side of the obverse. With a little hunting, collectors should be able to find a fully-struck 1877-S Half Dollar.