I may be wrong, but thought if the collar is cracked would be one way for the die to widen. Then evidence of that would show on the rim.
My thoughts were of a more subtle form of widening that could be achieved from the constant pressure from retaining struck planchets / coins over and over for a long period of time. That and other mechanical forms of stress and wear could lead to die fatigue (widening) without cracking. Thanks, Doug
edit: That said I would think the diameter would reflect that, which is not the case here.
Edited by Halo1st
08/30/2015 10:21 am