RIC only lists cuirassed bust for this type…compare with RIC 55
Constantine I
AD 313- 315
20mm 3.2g
CONSTANTINVS P F AVG; laureate, draped and cuirassed bust right.
MARTI CON-SERVATORI; Mars, helmeted, stg. r. and looking left; leaning on reversed spear, l. resting shield on ground; T-F across fields.
In ex. PTR
RIC VII Trier –