Case Neck sizing for good bullet seating

[Gun Geezer]

After several threads, I am obviously (trying) loading 348 Win. This a bottle neck case.

I've only loaded up about 6 cartridges so far.

Using dial caliper, the bullet is .348" and the neck ID is .3465" (as measured at the neck expander ball). I've been told that is "OK". Had trouble getting the bullet to sit on the case as I tried to seat it even thought the bullet is a bevel based jacketed bullet. Ruined one case.

What's the solution? What I heard from the guys at work:
- Chamfer the case mouth ID.
- Use a Lee Universal Neck expander to flare a tad.
- Use a RCBS Neck Expander to open the neck.

Also, is the RCBS Neck Expander normally the exact size of the caliber ordered? If so, there would be zilch neck tension.

OK: It's with you guys. Tell me what's what.

 

[243winxb]

Chamfer the case mouth ID. The expander should be about .0015" to .002 smaller than bullet diameter . Hold the bullet while you slowly raise it up into the seating die. Check to see if the seating stem fits the bullet ogive ok.