I've been taught all these years that both words described the same effect. There was no "MD" in the 1970's. The mint employees called this characteristic "die bounce" or "strike doubled." Can you please explain the difference as error collectors see it? I hate to be so ignorant on this topic.
Sure, strike doubling is like you said, from a bouncing die, which, causes the effect ( I put a circle around the area of question ) Strike doubling also causes the area around the doubling, to have damage done too .. You can see damage from the bouncing, that caused the area of question . Now lets take a look at the Machine Doubling, area is nice and smooth from the doubling . I put arrows on this one . As we can see, there's know damage around the doubling on the Machine Doubling .
@Rick Stachowski What you said about "damage" around the "doubling" makes no sence to me at all. I think you should have a talk with Bill Fivaz, or Mike Diamond BEFORE you pitch any more of those valuable coins away.
...and if I understand you correctly...the nonsense (IMO) you posted in #5 came straight from Mr. Potters mouth? Let me know 'cause Ken's going to have some explaing to do when I show him a printed copy of this exchange.
Can you explain what causes machine doubling that is different from strike doubling? I'm not sure the picture and line at the bottom really make it clear.
Everything is really caused from a loose die, just different stages of the loose die, once fixed, or tighten, all goes away ..
Okay, that's a little more clear. Now, why is it that you keep the ones you are calling machine doubled?
Now that single squeeze hubbing has taken over, less and less variety will be found . We will also have a whole new era of, variety experts too . Never know what the further holds ...... As for why do I keep one over the other, like everything else I try to collect, ( Early Die State )
I agree with this as will all the young and OLD variety experts and U.S. Mint employees. Now, I'm an old guy so please forgive me if I still don't understand your post. It would help if you could please answer my original question. What is the difference between STRIKE DOUBLING and MACHINE DOUBLING? In post #5, you say machine doubling shows "damage" around the doubling. In post #14 you say you only keep EDS coins. IMO, EDS has nothing to do with either SD or MD except it may change the appearance of the coin. IMO, NEITHER does damage. You seem to be a well respected and knowledgeable numismatist. As I always believed MD and SD were interchangeable to describe the same effect on a coin, I am still trying to get educated here! Thankfully, we are all free to collect what we wish. However, it is a bit of a stretch if the new era of variety "Ex-PERTS" start making up nonsense. I still cannot believe a well regarded error collector and author taught you that MD and SD are different.
I got tired of waiting so I did a little research on my own. I was wrong in my post (old age caused me to forget)! EJECTION DOUBLING was the term I learned was used by the Mint staff. So that's was what we called it in the 1970's. This is what I found on Wexler's site and sums up very nicely what I have always believed: "This form of doubling has been known by a number of different names over the years. It has been referred to as “ejection doubling”, “machine doubling”, “strike doubling”, “shift doubling”, and “shelf doubling”. If you see references to any of these, it is most likely mechanical doubling that is being referred to." I'll confess to never having seen one of these terms used before this so I learned something new. And from Mike Diamond: Machine Doubling (a.k.a. machine doubling, machine doubling damage, machine damage doubling, mechanical doubling, strike doubling, shift doubling, ejection doubling) (ES, July/Aug 2006; CW 3/15/10) EDIT
