Hi Daryl, I don't neck size any cases, always F/L to headspace dimension +/- .001", setting the decap exactly right is the key to minimising run out, but you know that anyway.
It's the bullet runout I need to sort. I'll check the seating stem & see if I can adjust it.

The 6.5x55 seating die from Hornady sounds like it's worth a try though, I'm sure I can borrow one to try out.

I seat the bullet to the canelure & roll crimp; I checked the runout before crimp & after, there's no difference at all, so it's not the crimp having an effect on the runout.
The 160 gn bullet seated & crimped gives an OAL of 2.949", feeds sweetly from mag to chamber & currently shoots 1 1/4" MOA groups, but it should do better.
As long as I can get it down to max .002" or .003" runout I'll be much happier.

I'm pretty sure the propellant charge isn't far from right.
Cheers, d