Ah brings back memories of my 1st attempt at loading pistol ammo.
Back that expander WAY OUT, you just want enough bell on the mouth to start the bullet. Back that seater die WAY OUT and get your seating depth where you want it then, take the seating stem out and turn your die down to where you get a slight crimp, go slow, take your time and if all else fails read the intructions that come with your die set.