It is MD really common on that spot, its from what I believe ( correct me if I'm wrong someone) when the coin is struck the coin shifts in the die causing that flat shelf like surface. Here are 2 photos to help you understand the difference between a double die and machine doubling.
Here are 3 links to the same site all about different types of doubling. Hope this helps and keep looking you are bound to find a double die one day!!! 1. Double die Vs machine doubling http://doubleddie.com/144822.html 2. Die deterioration doubling http://doubleddie.com/144843.html 3. Abrasion doubling http://doubleddie.com/144864.html
Don’t give up – keep looking. Just because the coin displays “Machine Doubling” doesn’t mean that it is not a Doubled Die. A few years ago we found a 1973-S Kennedy half dollar that had strong “Machine Doubling” on OF AMERICA but on other parts of the reverse it had characteristics of a DDR and when we sent it into Dr. Wiles, he gave it a listing of the DDR-003 (look at the pictures and judge for your self). http://www.varietyvista.com/1973SDDR003 half.htm Remember that the “Hunt” is the fun part of collecting anyhow!
