Posted 06/19/2016 10:20 am
The first question about a coin is this: "what is actually doubled?" Most of the time we often find MD that reduces devices. On your coin there is actually nothing that is enlarged, just that dreaded line of very slight machine damage after the strike. (die movement that damages one or more devices after the strike) Then looks for other devices affected. You will find that with the MD, the devices are reduced from this die movement. On you coin it looks like 'OF' is the only thing affected. If this were a doubled die, then you would expect several devices in that area to show hub doubling.
These are the devices you see around 'OF'. Note how the hub doubling affects the die. Not in a vertical pattern, but on the tops of the devices itself. The one I posted is not even listed, but a minor example. Another one? this one is actually Machine Damage caused by the multiple strikes of the coin. (proof coins are struck more than once. Sometimes 2 or more times for a larger coin)
Note that the doubling is not on the tops of the devices, but is actually at the bottoms near the fields on machine damage. The slight bounce altered just that area on the coin.
Here is a triple die example on the same areas. (on tripled dies, they also appear to be weak, but some areas will show the tripling) This is also a minor one:
On the USA devices you can find some doubled dies with all affected the same, weakening from left to right or vise versa. By knowing what devices and how they can be affected, will help in your search for a doubled die. Keep in mind the examples I posted are minor. So the devices are not enlarged a lot, but knowing where to look is a great aid for what to look for and when MD comes into play, what is wrong for hub doubling. Hope this helps
