Ron Guth:
1827 Half Dollars have the third highest mintage of the entire series, exceeded only by 1834 and 1836. However, they also contain some interesting varieties, including a 7 over 6 overdate and dates which feature either a curled base 2 or a flat base 2. The Curl Base 2 is the least common of the major varieties and much less common than the Square Base 2. Mint State examples are rare and typically range from MS-62 to MS-64. The finest examples certified by PCGS include 2 MS-65s (according to the March 2012 Population Report).