Question About DDR's On Lincoln Cents

Doubling is, in effect, a failure of quality control - which is of course why they are rare and sought after. A modern, high-tech, first-world mint like the US Mint ought to have very good quality control systems in place, to prevent such mistakes from being made.

I'm sure that after the 1955 debacle, the US Mint put extra procedures in place to make sure another 1955 never happened again.

Answered better than what I was prepared to type.

The move to the single squeeze method of creating working dies in the mid 1990's has cut way down on the possibility of any die being doubled.

Previously working dies were created by being heated and having the hub pressed into them. If a second pressing was needed to insure properly impressed dies, the hub and die had to be accurately realigned.

If not realigned exactly you ended up with a second impression on the working dies, sometimes significantly deviating from the first.

The advent of the single squeeze method, which as the name implies creates a die in one try with no need to realign anything, eliminates most of the potential classes of doubled dies.

Here are a couple more you can see with the bare eye, no magnification needed, beyond what others have already noted. Not 100% sure but have wondered if the hammer die, typically being the obverse might have something to do with it, maybe easier to have issues with when re-alignment after a second pressing was needed, or maybe more play, sloppiness in the hammer die, don't know enough about the mechanics to be sure.



LINK http://varietyvista.com/01b%20LC%20...4PDDR001.htm

LINK http://varietyvista.com/01b%20LC%20...4PDDR001.htm