southtexas,
Yeah, different bullets can seat considerably straighter in the same dies. I had an early lesson in this. My first .270 Winchester REALLY shot 150-grain Hornady Spire Points, as in 1" groups at 300 yards. I thought, of course, the rifle just "liked" them, but a number of years later, long after that .270 was gone and I'd gotten my first concentricity gauge, I tried a bunch of different bullets in the same seating die. The 150 Hornady Spire point seated MUCH straighter than any other bullet, probably due to the way the nose of the bullet fit the die.
In my experience, seating lighter (shorter) bullets straight is even more important. Heavier bullets with longer shanks tend to straighted out in the throat, or at least that's my guess.
