It appears I've got myself a rifle with a short throat. How short is still to be determined. When I get to my reload bench with an unprimed case, a couple bullets, seater die and a sharpie, I'll try to see whats happening.

That said... is there any upside to a short throated rifle?

All I'm thinking of is the limitations.

Limited to shorter bullets.
Limited to deeper seating and encroaching on powder charge, leading to...
Limited velocity?