Sons of Constantine I. Roman billion reduced centenionalis, 1.67 g, 15.5 mm. Heraclea, AD 337-340. Obv: VRBS ROMA, helmeted bust of Roma, left. Rev: GLORIA EXERCITVS, two soldiers holding one standard between them; SMHЄ in exergue. Refs: RIC viii, p. 431, 28; LRBC I, 941; RCV 16529. Notes: From the Doug Smith collection, acquired in 1992 from H. J. Berk. In the course of attributing this new purchase from AMCC's second auction, I noticed something confusing. It seems to be listed twice -- once in RIC vii and again in RIC viii. Do these two listings refer to the same coin or am I missing something? @dougsmit -- do you know? This used to be your coin! Here's the listing in RIC volume SEVEN (see no. 156): And here's the listing in RIC volume EIGHT (see no. 28): Feel free to post comments, related coins, or anything you feel is relevant!
They differ in module size. The coin dies were designed for a module of 16x17mm and 2.45 grams or so. However, when they had to adjust for inflation they sometimes used smaller planchets in the same dies, resulting in modules like 13x15mm at 1.67g, with clipped lettering. However, there is some crossover. My rule of thumb is this: when I can read the full mint mark and full top lettering, and the weight is 1.90 or above, I class it as the earlier RIC VII 156. Otherwise it is the later RIC VIII 28. However, I have not done or read any studies which verify these limits, so all this material is on the same page in my collection. I have 3 examples of 156, five examples of 28, and one that breaks the rules (shows all lettering but weighs 1.36g). You're reminding me that I should probably reweigh that last one. Actually, the obverse bust size is a good indicator of which module you have. The smaller module bore a smaller bust. My "undecided" is actually a 28. Add: forgot to note that your coin appears to be the earlier 156 despite the weight. And it's not a mule in the sense of an accidental mixing of die types. Two mints used this combination as regular fare.
