I recently acquired the Sinclair concentricity gauge and am now determining what steps of my reloading process are contributing to bullet runout. I’m currently reloading for my .204 (Hornady brass and 39 gr SBK pills). Once fired brass give less than 1 thou runout. Brass resized using a Lee collet die also give less than or equal to 1 thou runout. When seating bullets using the Lee “dead length bullet seater” (the one that comes with the collet dies); I’m seeing anywhere from 1.5-5 thousands of runout in the loaded ammo with most averaging around 3 thou. Measurement is taken on the ogive close to the ballistic tip. I have noticed brass with a more aggressive case mouth chamfer helps with runout so I have went back and re-chamfered the brass with a VLD style chamfer – even with this, I’m still seeing high and inconsistent runout. I’m not sure what bothers me more, the high runout values or the extreme spread (one round will be 2 thou runout and the next will be 5 thou). Also noteworthy; I’m not using the lock nut w/ O-ring provided with the lee seating die. I’ve replaced it with a Hornady-style collar. Suggestions appreciated; thanks.