After resizing I observed some interesting marks (line circumnavigating the case just below the shoulder) on my fire formed cases after resizing. My initial impression was this had to do with #2 (above) during the FL resizing.
Then I went and inspected some additional fire formed cases (no yet resized) that were only fired 1x through the rifle. These cases also showed similar marking. My thoughts are this is the intersection of the shoulder on the .223 Rem before it was blown forward during the fire forming to 223AI.
Then I went and inspected some additional fire formed cases (no yet resized) that were only fired 1x through the rifle. These cases also showed similar marking. My thoughts are this is the intersection of the shoulder on the .223 Rem before it was blown forward during the fire forming to 223AI.
