Pen point indicates where the internal base begins. Notice the formed slits 180 degrees apart, they are not case ruptures.
http://db.tt/ir5GCSD8
Looking into the case you can see the aluminum tube that extends from the primer pocket.
http://db.tt/VITdwMuV
Looks to be a standard primer, the odd ring is a reflection.
http://db.tt/8jAbNxXM
ETA: One concearn would be the possibility of bullet setback. Could a split polymer neck place as much case mouth tension as traditional brass? I am sure there was extensive testing done, but not sure how I feel about that.