TON Collection

Hi TON....
I see a couple of carbon spots that I think will keep your coin out of that grade range, sadly.  I wouldn't bother submitting it.....pronounced carbon spots can definitely hurt the grade on copper (or copper-plated) coins.

Hi TON,
Unfortunately, I don't see any doubling on your coin from the photo provided.  It's possible that you have some machine doubling that isn't showing up in the photos or possibly what they call the "Poor-Man's Doubled Die", which actually isn't a doubled die at all but the result of die deterioration.  Here's a page that explains about the "Poor-Man's Doubled Die"
http://www.lincolncentresource.com/FAQ/Poormansdoubleddie.html
Since the 1955 DDO caught on so big with collectors, the "Poor-Man's Doubled Die" is a rare instance of die deterioration sometimes bringing a premium because many dealers over they years have heavily marketed it.
As always, I hope that this helps you out!
~Tom

I’m hoping this is good enough For grandfather double die .  I have the real one graded and it’s obviously more dramatic but what u guys think about this one

Thought I'd look into possibility of wrong planchet/foreign planchet just to rule it out.  https://archive.org/details/domesticforeignc00unit80/page/100 
Starting on page 99 is foreign coinage amounts by country, mint, content, weight, diameter.  I didn't see anything produced in San Francisco in the 70s that would indicate a foreign planchet could be the reason.  The lowest comparable weight on a 90% silver coin produced is 26.73 grams.  
90% silver AND 21.6 grams should result in a coin a little smaller than a Morgan (not accounting for thickness).  Or, as Conder pointed out, 5 grams smaller (or 79 grains if you insist on using the Standard system referenced in the US portion of the book).
.....
Beside all that, this is a really cool book I'm glad I came across so thanks for that @TON Collection  Pretty sure they have the publication date entered wrong since the production figures go all the way through 1980.

The next step would be a specific gravity test.  90% silver has a SG of 10.34, 40% silver SG is 9.53, and coppernickel clad is 8.92.  These figures are far enough apart that it should be fairly easy to determine which it is.  The tissue test does seem to indicate silver or silver plated but I don't think you could silver plate a proof and still have the mirrored fields.  So 40% or 90%, and if it was 90% with that low a weight the coin would be visually noticeably thin.  I'm still thinking a severely underweight 40% silver planchet.  (Assuming the scale is accurate.)

Got the scale 
If he has a water bath that will tare on his scale and still weigh out he can do it himself to answer sp question
Coin weight in grams divided by coin weight bathed in water (Coin Suspended in water and not touch sides or bottom of vessel ) = SP of coin
Look forward to results
 

Tissue test seems to indicate it IS silver, so it is apparently a severely underweight (thin) planchet error.

I'm seeing an "S"
I still have no idea about the coin, unless it is an underweight planchet.

In my FIL's collection I found five gold-plated 1976 Ikes. I think my MIL had bought them for him off a TV channel, innocently thinking this was a Great Thing. Don't know if that has bearing on this. (I couldn't stomach having them in my collection, so I distributed them among his grandkids (my nieces and nephs).)

No worries, cracking a slab can be done in many ways for myself I just set the slab on edge and start giving it love taps along the side of the slab.  Usually only takes a few before the slab cracks along the sonically sealed edge and falls apart leaving the insert and coin free.  I only do this with coins that I have wanted in my 7070 album, and many of those are problem coins, low grade coins, or junk slabs (NNC, SGS or the like) where the slab doesn't add much value.  Another reason to crack a slab is to submit a coin raw, I once cracked an NNC MS68 Lincoln coin and submitted it PCGS where it graded MS67, rare for on of these holders to grade so close.  The key is not to go wild swinging the hammer or you might damage the coin, another way I've heard is to use a bench vise to squeeze the slab into breaking apart but haven't tried that method myself.  If you ever do decide to try it cover the slab with a cloth, those slab shards can fly and are sharp.
 
And to keep things on track.
 

Awesome Indian Head cent.

Picked up all these Eisenhower and Morgan at same shop today under 40 dollars type 1 bicentennial 

Another looker

Wow nice additions of the NGC old fatties

Also acquired this 1955 double die. I couldn’t pass it up

What you guys think? Grabbed this today

What you guys think? Grabbed this today

What you guys think? Grabbed this today