Need Help With Bullet Runout

[338 dude]

I am getting inconsistent and visibly wobbly bullets with my new brass. New Lapua 6.5 Creedmoor brass, prepped as follows: case mouths lubed and expanded with 21st Century TiN expander mandrel, neck mouths vld chamfered on LE Wilson hand case lathe, necks deburred with Forster deburring tool, primers installed with 21st Century hand primer, powder added with the V3 autotrickler, Hornady 153 grain Atips seated to a COAL of 2.950" using a LE Wilson micrometer seater and K&M arbor press. I also tried my Forster micrometer seater die in my CoAx with the same result. Out of fifty rounds, perhaps five have no visible runout at the tip. I have the Accuracy One concentricity gauge as well. Measured just beyond the case mouth, I am getting 2-4 thousandths runout, and it gets progressively worse towards the tip of the bullets. I simply don't know what is causing this.

You stated new brass and expanding it with an expanding mandrel but I like to run mine all through a full size die to start with Then the mandrel etc.