Quote Originally Posted by justdave View Post
You may have to back the seating die out and run the spindle back down. Even if you have no intention of crimping, you may be bumping the the inside of the die when seating a bullet.

I think you're right Dave and if the neck lengths varied it could be why some wouldn't chamber, those with slightly longer necks were/are bottoming out in the seating die and collapsing the shoulders

Bill