Ok . I've been hanging onto this for awhile . Anyone know what to call it ? Die Crack ? It's strange .
Assuming there's no damage to the edge in that location, it could be finned rim that was folded over in circulation
Looks cud-ish...meaning, the die was on the verge of becoming full-blown cud. An awful lot of metal for finning, and the rim shot (ba-dum-dum) appears to show no shearing and looks complete at that angle. IMO, could be either...Spark
Not quite a full blown cud. I would wait for more experienced CT'ers to offer their assessment. Good luck.
During the Upsetting process there could be pre-strike damage that occurs during the raising of the rim. I believe it is called a a pleated apron. This is a form of circumferential pre-strike damage. IMHO. You don't have to agree