You're welcome. The reason behind the weight variance is this: the Romans did not measure the weight of each flan. The minters were given a certain amount of bronze, and were told to make a certain number of coins with that amount. I'm sure they got very good about "guesstimating," but it was nevertheless not an exact science. Silver and gold were another matter - they were much more careful about measuring precious metals.
I agree with JA said in his posts. Myself, I do not think wear was a factor. In modern coins, the coin has to get down to VG to have any noticable weight affect, and certainly not that high of a percentage. What happened here was corrosion. The surface corroded, and when it was dug up and cleaned a considerable amount of its weight was removed with the cleaning. Also, given that assumption, some metal might have been leeched out of the flan during burial.
Yes and beyond that we need to know whether a particular issue was tightly controlled or known to be really sloppy from coin to coin. There are coins that a .5g variance would be a concern but this one is not in that category and the poor thing has suffered greatly in the hands of a really nasty coin cleaner. That alone would take the .5g. I do not have the exact coin but this one from a different officina of the same mint was purchased in 2000 from Victor Failmezger (he wrote the book on the period) for $10. It is RIC volume VI page 519 61b (rated common). The $10 price was due to it being so common and the poor reverse strike but the obverse is nice. The flan was too thin (as was yours) to fill both dies with metal available and the reverse lost the fight. It weighs 2.2g. Your coin lost weight to corrosion; mine lost it to sloppy mint practices. My Licinius of the issue bought the same day from Victor (also $10) is RIC 60 page 519 weighs 3.0g and has a better reverse strike. RIC still insists the coin should weigh 3.75 to 3.25g but I'm wondering where they got their fat coins. Nothing at all. I would, however, forgo the fries with that Mac and spend the extra cash on a slightly better specimen that had not been butchered in cleaning. Today my coins would not be more than double what I paid from a fair dealer or 5x from an extortionist. If people stop buying the butchered coins maybe they will slow up on the coin abuse and clean with gentility. My goodness, I have too many coins.
Pecunia non olet! Here's my ten-buck Licinius... You did better with your $10 than I did with mine. You know, it's funny, but I haven't chased these coins precisely because they're so common. They will always be there, and they will always be cheap. I suppose I should buckle down and get a really nice examples from both Constantine and Licinius.
Yes, you should. I wish I would have buckled down more and bought nice, high grade coins back when they were cheap. High grade coins tend to attract collectors. I remember tetrarchy follis' used to be exceptionally pretty and inexpensive. Now any attractive one you find is priced accordingly, they are no longer cheap.