Ned Ludd
Silver $$ Contributor
If you're using an expander mandrel that is .001" under caliber as a sizing step to set your neck tension (interference fit) after using a bushing or neck sizing die that sizes the necks slightly under the final diameter, you should have neck tension of ~.0015" due to spring-back of the brass. I would not consider that excessive in terms of your issue with the seater stem. Although you and others have already noted that Hornady suggests using their seating die stem with A-tips, it's probably worth re-iterating. I recall seeing Hornady's recommendation for the use of the special seating die stem when the A-tips first came out. At the time, I remember thinking it might be necessary so as not to damage the aluminum tip. However, your issue with bullets sticking and rings around the bullet noses suggests there may be another reason.