This is really dumb and I'm sure I'm having a senior moment. Setting up RCBS FL dies for 30-06, this time just to get a baseline before measuring headspace taking once fired brass and bumping shoulder. Just FL sizing per RCBS instructions.
Shellholder 3, raise ram, just kiss, back off ram, turn in 1/8-1/4, lower ram, cams over. I deprime with a Lee Universal deprimer so the RCBS depriming stem depth is not important, though it's roughly 3/16" or so.
Place a lubed deprimed case into the holder, raise ram....and case gets stopped solid with about 1/2" about between the shellholder/ram and press. Case is not fully sized. For the life of me I can't figure out what's going on.