Ron Guth:
In 1871, Dime production at the Philadelphia Mint ramped up to just over 900,000 coins, the largest mintage since 1861. The 1871 Dime is not the cheapest example of the type, but it is one of the most affordable. For some inexplicable reason, the 1871 Dime is more scarce in Mint State than even the 1870, which has almost half the mintage. The most frequently-seen grade for this date is MS64, though that grade is flanked on either side by nearly equal quantities of MS63 and MS65 examples. MS66 appears to be the highest possible grade, and there are several examples available at that level.
Thus far, researcher Gerry Fortin has identified fourteen different die pairs for the 1871 Dime. Because of the large mintage, it is possible that new varieties are "out there" waiting to be discovered.