Re: Hornady Custom Grade "New Dimension" 2 Die Set? Good?
"...my idea is if the expander ball can float it might not pull the case neck crooked . I don't know if this is true or not ..."
Sounds true but it's not much use. Expander balls rarely pull necks out of line. It's a common idea but they can't do much of that IF they are centered.
Necks get deformed during expanding mostly because of variations in the necks themselves. Thin spots and soft spots give way under the stress of expanding and the ball drifts that way. The resulting "bent" necks may even be worsened if the stem is loosely held. A solidly held well-centered decap rod does have some small potential effect , but not a lot.
It IS helpfull IF a decap stem is held centered in the die. Lee develped that small collet clamp holding system to do exactly that. Hornady copied it, added shallow threads for a nut for those who won't tighten it enough to keep it secure and called it a "Zip Spindle." That's a very good design but it MUST be firmly held to accomplish any good it can do.
Seems the "best" expander is one made in a longish cylinder as Lee does it; the contact area is much greater so small localized neck variations can't do so much injury to the end result as a smaller contact area will permit.