1966 Quarter RDV-005. FS-801.

Due to the flat appearance, less spread, and lack of split serifs in the "doubling", I believe that what's on the coin is Machine Doubling, not a Doubled Die.

Is the designation not what I have in the title? I'm very confused at this point. Lol now the leaves I can understand becusd there is no split. However the lettering I see no splits nor an obvious doubling from the example vv gave.

Thank you silviosi so I would look for the error as a whole with all lettering on the reverse correct?

Appreciate it Sam I can understand that explanation. Geez finding errors is harder than I thought lol

Also, to answer you question in the post, to be a doubled die, ALL the doubling needs to match. To understand why, let's take a step back and talk about how doubled dies are produced. For simplicity, I'll restrict to coins minted before the introduction of single squeeze hubbing, which became the standard for US coins in 1997. For coins minted before 1997, dies were produced in multiple stages, using a positive engraving of the design called the "hub" and a hard metal cylinder called the die blank. The image on the hub was transferred to the die blank by impressing the hub into the surface of the blank under immense pressure. However, because the die needs to be quite hard in order to strike coins without immediately deforming and losing detail, it wasn't easy to impress the image from the hub all the way into the die in a single go. The Mint's solution to this problem was to perform a series of hubbings (impressions of the hub into the die blank) and annealings (softening of the die blank between hubbings to make the die blank receive the hubbing more readily). A doubled die would be created when, between subsequent hubbings, the hub was aligned slightly out of position with the previous hubbing. This would double the image imprinted on the die (hence the name "doubled die"). There are many ways this could happen from rotational misalignments (Class I doubled dies), to pivoted misalignments (class 5), to more complicated examples where a different hub was used that caused a distended second hubbing (Class II/Class VI). In total, there are 9 generally-accepted classes of doubling, and I encourage you to read up on all of them in depth, as it will help you to better understand what doubled dies look like. The important thing to understand, is that the doubling on a doubled die is a property of the die itself. Thus, every coin struck over the course of that die's lifetime will exhibit exactly the same doubling as every other (give or take whatever detail is lost to polishing/die wear). This is why we can catalogue dies in the first place, since every coin struck by the same doubled die is, in essence, exactly the same.

I appreciate your time and reply sam, I will definitely look further into these classes so I can truly understand. Is there an existing thread here on CC? If not there should be because this was really informative. Thanks again!!

Sweet! Looking at it now since I have some free time, appreciate it.