I find the Hornet is sensitive to how the brass is handled.
The Hornet has thin brass, so using ordinary dies puts stresses on the case -- the walls can bulge as the neck is forced into the die, and it can be stretched as the expander is pulled backward through the neck on the downstroke.
I use a Lee Collet Die, with two washers on the shell holder. This causes the collet to activate early, resizing only about 0.2" of the neck. The remaining unsized portion of the neck acts as a pilot to center the bullet.
I also find the Hornet sensitive to seating depth -- my M82 kimber gives gilt edge accuracy with the bullet actually touching the rifling.