Interesting Die Gouge On The Reverse Of This 21-P Morgan

Indeed, there is an exhaustive list of VAMs for 1921. I can only study these until my eyes cross, then I have to stop.

Chance

There's a certified 21-S on ebay right now that's been suggested is an adjustment strike. It's a bit more pronounced than this Denver issue, but the lightness of strike is over the entire coin, obverse and reverse.

Here's a link to that listing:

http://www.ebay.com/itm/1921-S-MORG...em4ae90cab51

Chance

Sorry for the overnight wait - I wanted to forget about it for a bit and revisit my thinking fresh. What follows is the numismatic equivalent of wide-eyed speculation, and probably shouldn't be taken as Gospel.

Whether or not yours is an adjustment strike isn't relevant here. Methinks is probably is, but the Mint turned out some truly execrable product in 1921 and one must always factor the pressure to produce at such a high rate into these things.

The important thing I glean from your coin is a pretty good hint about the order in which die devices fill during a strike. As you know, the planchet metal adopts liquid properties during a strike. Metal actually flows, on order to fill the areas of varying volume disproportional to the amount of planchet metal available at that exact spot. This is how flow lines come to be, and we know it to be in a generally center-outward direction. That's why dies were basined, ground into a slightly concave configuration to help metal completely fill the periphery of the die.

Now for the wild-eyed part. During the strike, planchet metal flows into peripheral lettering at a pretty high rate of speed (at 150 strikes per minute, the coin has 0.4sec to be inserted, struck and ejected) and splashes against the first thing that impedes its' progress - the spots inside the letter which meet its' progress at a 90-degree angle. That's why the ridges we see are on "horizontals" on the sides of the letter away from the center. Then it begins splashing back into the deepest part of the letter and fills the letter upwards In an adjustment strike - or by definition any strike with "sufficiently insufficient" pressure - that initial splash and a partial letter fill is all that happens. It can't finish.

That same thing happened to both of our coins. Yours was caused by pressure insufficient to even fill the letters, possibly along with poor basining. Mine was caused by what I'm theorizing to be a slightly-compressible strikethrough/fill which slowed the process sufficiently or stopped it completely.