The run-out in the .257 Wby is back (or it never left this particular die). The die is a RCBS Neck Sizing Die (not FL resizer) If I leave the expander ball in the die, I get .004+" run-out. If I take the ball out, the run-out is .001" to .0015". From what I can measure, a fired but not sized neck I.D. is .259/.260 from the Vanguard. With the sizing ball in, the I.D. measures .255. With the ball out, the I.D. measures .249. This is NOT a bushing neck sizing die, so I cannot vary the amount of squeeze that is put on the case neck. Is the I.D. of the neck too small for seating bullets without the ball expander in the die? If so, what amount of interference fit should I be looking for between the neck and the bullet? I have a .25/06 Lee collet die that I changed to work for the Wby., but since I have two .257 Wby rifles, and I know that the chambers are different, I don't think I will get the best results using the same neck sizing die for both guns. FWIW, the fired cases from the Mark V measure .255"/.2555" I.D., and the fired cases from the Vanguard won't allow the bolt to close when put in the Mark V chamber before resizing. I don't mind buying a bushing neck die, but with a 30+ day wait, I'd really like to get this problem solved this week! I tried lightly coating the neck with Imperial inside and outside, and also tried mica inside. All the cases are tumbled before they see the die (even the new ones). Suggestions/tips/hints???