2007 P SMS SAC - Double Struck or MDD?

Russellhome · Veteran Member

I realize Mechanical Doubling Damage (MDD) can take several forms, but from what I normally see, it tends to go one direction (not in a circle around the coin, as in this example). Plus, it often times evident on the rim. On this Sac $1 - I don't see any MDD at the rim, either obverse or reverse. And if the coin was not struck twice, how did the SS/SS form? Was it a quick 'bounce' with the coin rotating slightly in place between the hop? If it is not a double strike, then it sure looks like it falls into some gray area between MDD and and an in collar double strike.

In case you are interested... I took more photos after cracking it out of the package. They are large (broadband/DSL recommended) and more detailed. I did them as links so I would not freeze up any dialup users.

http://www.idsimis.com/photos2/2007PSacSMS_rev1.jpg

http://www.idsimis.com/photos2/2007PSacSMS_rev2.jpg

http://www.idsimis.com/photos2/2007PSacSMS_rev3.jpg

http://www.idsimis.com/photos2/2007PSacSMS_rev4.jpg

http://www.idsimis.com/photos2/2007PSacSMS_obv1.jpg

http://www.idsimis.com/photos2/2007PSacSMS_obv2.jpg

http://www.idsimis.com/photos2/2007PSacSMS_obv3.jpg

http://www.idsimis.com/photos2/2007PSacSMS_obv4.jpg

http://www.idsimis.com/photos2/2007PSacSMS_obv5.jpg

mikediamond · Advanced Member

Occasionally machine doubling does produce clear separation of design elements.

Bob P · Site Admin

I agree with Mike's loose/rotating collar theory. However, the part about the additional die chatter may not be one of the other characteristics. I had a few of the 2001P half dollars that he mentioned. The consensus at that time was that the collar was indeed loose, and when the coin was ultimately struck, the result would be a more severe form of machine doubling. If the collar is loose enough, no additional chatter would be required to produce an effect such as is shown. One of the diagnostics would be to see it the machine doubling rotates in the same direction on both side of the coin. In this case, it may be that the collar slid to one direction once the the initial kiss of the die was made. The strength of the doubling leads me to believe this may be the case.
I was led to understand that it also happened on some first year Sac dollars.
I ultimately sold all of the half dollars I found (5 of them), but may have kept one. If I do find it, I will post pictures for comparison, or send it to Mike for his analysis with his permission.
Either way, and no matter what the ultimate cause, this is a beautiful specimen and excellent pictures. I'm with Mike on this one. To a collector of like items, it could be worth a substantial premium.

mikediamond · Advanced Member

I would think some die chatter was involved. If it was just a forcible rotation of the collar as the hammer die withdrew, then you'd see a smearing of the design ("slide doubling), rather than a clearly defined marginal step ("push doubling").

Russellhome is correct in speculating that it might be impossible in some cases to distinguish severe machine doubling from a double-strike involving a light second strike. So far I don't think I've run across such a situation, but I see the potential.

I've seen many examples of severe machine doubling on 2000-P Sacagawea dollars. However, they've all involved translation (lateral movement) rather than rotation. And all but one involved the obverse face alone (the obverse face was struck by the hammer die at that time).

Bob P · Site Admin

Definitely makes sense to me Mike. I was responding with the info given to me in 2001 for the half dollar errors. I am not an error guru such as yourself, but I definitely see the soundness of what you are saying. As far as the 2000P Sac dollars, you are correct in that almost all showed just lateral movement with the doubling confined to one side. However, the reported specimen(s) did have the strike doubling on both sides, although not near as pronounced, or with the spread of Ken's beauty. The interesting aspect at that time was the separation and duplication of the obverse designers initials...almost exactly like those Ken shows.
I just plain like Ken's coin and consider it a nice collectible. Since it was found in a Mint Set, there may be more out there. I am expecting my order of the mint sets any day now. Maybe I can get lucky too!

mikediamond · Advanced Member

Here's an article that y'all might find helpful. It shows a number of different kinds of doubling from direct die contact.

http://www.minterrornews.com/news-1-30-07-doubling.html

Russellhome · Veteran Member

Nice reference for MD Info. It is amazing how many ways MD can occur -- and this Sac didn't seem to fully match any of the examples. The doubleing of the FS initials in figure 3c did look much like the SS initials on the SAC.

FYI: I did go back through the 15 sets I bought and did not see any more examples of this boldly machine doubled Sac. So if that die pair was throwing these out left and right, my sequence of sets only got one of them.

I did, however, find two examples of a very minor DDR on the 2007 P SMS Jefferson dollar. Doubling is in the same place as those that have been reported for the business strike -- the center of the coin where Liberty's arm, sleeve, and crown point meet. Compared to the ones already reported, mine would be near the bottom in terms of significance. But -- a find is a find. And perhaps there are better ones out there - so don't forget to look at that location on all the Prez dollars.

coppercoins · Site Admin

I digress to the opinion/expertise of Mike Diamond on this subject. I believe the coin to be more than typical machine doubling, as I have seen thousands of examples and not one was as imoressive or as clearly separated as this one.

I do not believe this coin to be an example of hub doubling in any form...just stating this for the record.

I do believe the dies had to have dislodged from the coin and repressed the coin for this to have happened so clearly and so neatly. I do not know the mechanics well enough to explain it, but if it is machine doubling, it's a new type as far as I'm concerned.

wavysteps2003 · Expert Member

And who said machine damage doubling is not collectible?

I am sure that Mike will be able to add to what we have seen in the exellent pictures provided when he does examine the coin.

I do agree, this is not a doubled die nor a die defect, but a strike (after) related phenomenon. I recently saw the same effect, however, very much less pronounced, on an obverse Ike dollar. The doubling damage was centered around "In God We Trust" with the greater spread seen closer to the rim decreasing as it went towards the center. It had been mistaken for a doubled die.

The rotation seems to be in a clockwise direction, indicated by the secondary doubling being in opposite direction on the date when compared to "In God We Trust".

As for the doubling seen on the incused designer's initial, that has also occurred on some of the more pronoumced MDD 1969 Lincoln cents from San Francisco on that same design element, the designer's initials.

What is particularly intriguing is that there is MDD on the reverse as well. I can not remember seeing that on any coin that I have encountered.

Well anyway, an excellent find and a great subject matter coin that I am sure Mike will do a fantastic article on.

CONRTATULATIONS!!!!!

BJ Neff

Russellhome · Veteran Member

I took a photo of a Sac dollar with normal designer initials (right) and a photo of a coin with a moderate case of good old fashion MDD (center photo) to see how they looked side-by-side with the doubling on the Sac dollar shown in this post.

The MDD on the coin in the center photo clearly doubles the width of the letters - and would have the characteristics of a doubled die if the letters were not incused. But it is not fully separated, like the photo on the left and not nearly as impressive. Note also how the stripes on the clothes are affected. It went from a seam to a pinstripe.

Mike has the 2007 Sac now. Hopefully he will gain some new insight as to the cause of this bizarre coin once he examines it under a stereo scope.

Russellhome · Veteran Member

mikediamond · Advanced Member

I've now finished looking at your coin. It really is a peculiar-- and spectacular --specimen. I'm now leaning toward a true double-strike, with the second strike weak. The doubling is too uniform on both faces to make machine doubling likely. It shows the same amount of rotation on both faces and in the same direction. The amount of flattening is the same on both faces.

The edge of the coin shows no partial collar "step", which is something that usually (though not inevitably) accompanies an in-collar double-strike. It's possible that after the first strike the collar rotated slightly before the second strike was delivered. Since the freshly-struck coin was fitted tightly into the collar, it would have followed the collar's movement. That's just one scenario, of course.

A weak second strike is indicated because where the first and second strikes overlap, the first-strike elements are not completely flattened. How likely is a weak second strike?

Several months ago BJ Neff found an in-collar double-struck cent with a weak second strike. It, too, showed no partial collar. So we know such errors do occur. And a few months ago I saw a 1966 dime with the same sort of error.

It'll make for a great article. I'll take some photos and send it on back to you. As to value, I expect it will be considerable. Of course, you'd have to get it slabbed as a double-strike, and I can't guarantee that. Because it bears a strong resemblance to machine doubling, the grading services may call it that way.

wavysteps2003 · Expert Member

Russellhome · Veteran Member

Wow - that is great news Mike. A ‘real’ find is exciting – no mater who makes it. I’d prefer the 1969 S DDO – but this will do. Thanks for taking the time to look at it. I will most likely try and get it slabbed as a mint error. With your expert opinion (and a copy of your Errorscope article) - it just may pass as a double strike - and my first significant non-Doubled Die 'find'.

I've been at this hobby for about 2 years now and I know I've made a lot of rookie mistakes. Coins with MDD, die deterioration, ejection doubling, and master die doubling have fooled me many, many times. Over time, I have gotten better at it and I'm now a little embarrassed about some of my earlier posts.

But this coin did seem different, so I decided to post it here and get some expert opinions. I hoped I was not just looking through 'rose colored glasses' and seeing what I wanted to see (which is something we all do). It was certainly different enough keep - but it almost went into my novelty collection of major MDD, strike through, die clashes, etc. Now I am really glad I decided to risk embarrassment and post it. Just maybe, I’m not a rookie anymore.

Again - thanks for taking the time to examine it and posting your thoughts here.

Russellhome · Veteran Member

I did a little horsing around with images of this coin today. I wanted to see if I could get an accurate reading of the rotation that occured between strikes. The image software I use allows for precise rotation of objects, so I was able to use that feature and do an overlay to determine the approximate rotation.

In the photo below, the darker stripe near the rim is the part cut out to show the underlying image - which was rotated slighly clockwise. The the lower part if the split image represents the approximate location where the 2nd strike came down upon the first. The rotation is just 1.2 degrees. I guess it did not take much.