RE: Resize 30-06 to .280?
Driftrider gave you good advice. The only thing I would suggest you do is set your resize die to a firm bolt closeure with the newly resized '06 case to .280. The "bulge" in the neck is the beginning of the new .280 shoulder.
Too bad you didn't get a bunch of .270 brass....they have a longer neck. You run a .270 into the '06 die to expand the neck, then into the .280 die to set the new shoulder. Fireform as you were told. I personally use some junk bullets and a mid-range powder charge of the manual's recommendation.