I'm with Rothhammer on this.
A lot has been written over the years about the Schoenauer rotary magazine, especially the early pattern,
being quite fussy about feeding only the "correct" cartridges.
Looks to me like the original long round-nose bullet engaging the feed-ramp may well lift the case-shoulder
clear of the obstruction before damage occurs.
Not sure if anyone has experienced reliable feeding with lighter/shorter spitzer bullets in lieu of the normal
heavy round-nose projectiles.
If you haven't tried it already, I'd certainly recommend giving RNs a go before arcing-up the Dremel.
They're more "pukka" anyway!