Are There Any Regular Issue US Coins With Sheldon R-6 Rarity?

Seems like gold might be a place to look. 1861-D $1 only has 30 graded at NGC for example.

Well, there is only one known 1652 NE threepence, but you probably don't count that as a US coin, although certainly it was a "regular issue." There are 12 surviving 1933 $20 with only one legal to own, but does regular issue imply authorized release to the public? The original mintage of 1804 dollars was much less than 30, but I don't recall how many types 2 and 3 there are, or where that fits into your definition. Same with the 1894-S 10c - they're designated as proof but technically they aren't, and again depends on what regular issue means. 1873-CC no arrows dime has only one, but are you excluding that as a variety? Others to consider - 1866 no motto $1, 1870-S $1 (I don't know why you're excluding that one).

Perhaps the 1795 Jefferson Head cents, plain edge

I am looking for straight circulation issues and trying to stay away from varieties. I used to own an 1846-C half eagle and was disappointed when my "rare" R-6 became a "less common" R-3. I suspect that a lot of my raw R-4 and R-5 coins will drop too, as more raw coins are slabbed and tallied.

I have a reasonably uncommon 1794 S-23 cent (R-4 from what I've read, but PCGS has only slabbed 4) but I'm not really looking for that kind of rarity. I like the cent though - Liberty looks like she has the mumps.

Because I search for rare coins when I can find them kbbpll. And Sheldon is my standard for rarity. When he set up his criteria it was just a broad scarcity by date. He identified the large cent varieties, and was one of the great collectors of them, but that is a refinement beyond the R classification. The 1794 head of 1794 cent has 66 (? hard to count them accurately) Sheldon die varieties. But in the broad rarity classification it is a coin with 3000 population, which makes it an R-1. There's nothing disappointing about the coins at all, but they aren't rare.

The populations of those R-6 and R-7 half eagles are pretty well set at this point and unlikely to increase.That level of rarity commands very high prices these days.

One thing to keep in mind when reviewing "rarity scales" is that - like any other survey - they are only as accurate as the number of people who report to them.

For very rare coins with very small populations, where each individual coin is constantly tracked (e.g. 1804 dollars, 1913 V nickels) this is not an issue.

In Mr. Sheldon's time, when determining the rarity of large cent varieties, rarity was based almost entirely on word of mouth among a very small group of collectors - access to actual records from auctions and collectors was difficult, mostly the job of correspondence by mail and research in libraries.

As information availability and sharing continually improved, new research was performed, access to data improved, and communication became much easier, it was necessary to revise a great many of the previous rarity estimates for all of Sheldon's varieties except the very rarest; and even today, new examples of very rare coins are turning up, pulled from a farmer's field, or a dusty forgotten box in a museum, or an inherited pouch of coins passed down for two centuries that is just now seeing the light of day. This can also happen with, e.g. the discovery of hoards, or the release of large amounts of coins previously stored away in bank vaults, etc.

The takeaway from this is that rarity ratings are not fixed - they are variable, and they can and will change as time goes on; and this variability is proportional to the existing population as reported. In other words, the less rare a coin is, the more likely a rarity rating for that coin will be inaccurate, and the more likely that the degree of that inaccuracy will vary.