I am new to this hobby and love using this forum to gauge my grading and trying to learn as much as I can. Not being familiar with the 1930 S, could anyone tell me if the "AT" in STATES, "OF", and "C" in AMERICA is a typical characteristic for this coin?
Typical for the year, not really. It looks like there was a touch of grease on a fairly well used die. However, it is not as bad as the picture makes it look.
San Fran was still working on some problems they had starting in 1920 with quality. All of the coins they produced through the 20's are known for their awful strikes and bad planchets. Things started improving in 1928 - as I recall the S mint workers where threatened by management- so they were still working on things in 1930. This coin had a partially filled reverse die. Grease and other particulate matter accumulates in the die recesses and prevents it from full striking-up the coin. It happens to ALL US coinage. As soon as it's spotted a mint worker changes out or cleans the die. This coin shows obvious signs of the problem. Typically, filled die coins do not effect the grade until you get to MS-65/66 and up. Back to y our question..... No, this is not a specific characteristic for the issue. The filling/clogging of dies is a random occurrence. There are plenty of well-struck 30S's in the marketplace.
Here's a learning coin- When die pressures are slightly off spec (weak) on a Lincoln, you will see weakness in the high points of the design: cheek, jaw, shoulder, temple-area, O in ONE, AM in AMERICA. This due to poor metal flow into the recesses of the obverse die - it takes a lot of metal to fill the head and shoulder areas- so the end results is these weaknesses in the strike. This coin shows it almost perfectly. Notice the "scratchiness" of the shoulder, cheek, temple and jaw. Those are tell-tail signs of inadequate die pressure. It ALWAYS affects the O in ONE on the reverse and the AM usually to a lesser degree.
First off, thanks for taking the time to give me an explanation. Ok, lets see if I have this right, so it sounds like you are talking about two different situations that occur during the minting process. The first issue/condition that you described is clogging of the die that results in a weak strike. Which is what I was unsure of in the original coin show and your example. The second issue you described is when the die is not gauged to the proper impact pressure and would result in a weak strike on the high points of the coin in the form of scratch like markings on the obverse that translate to the reverse side of the coin as a weak strike. Does that sound right?