The eaasy way to check before firing nosler brass in your .280AI
A homemade comparaator made with my reamer.
An unfired Nosler case.
A fired .280 Nosler case.
Case fired in another 280AI
an unfired nosler case, a fired nosler case and a fire formed .280 case. Notice the difference in the shoulder. How much money do you think Nosler would lose if you could not fire their brass in older .280 ackleys? Do you think maybe they figured out that changing shoulder geometry would allow cases to headspace in both old and saami spec chambers? I dunno but given the lack of warnings on both nosler loaded ammo and nosler brass in an industry where every little thing causes a lawsuit, maybe they did figure it out and it was not accidental.
I think maybe the sky is not falling, but I would still check it with at least the tape before firing.