New Brass and Neck Tensions

[NorCalNative]

This is my first go at using factory new brass, someI new brass from Hornady (.270win). When seating the bullet I had to readjust the die and needed to pull the first three rounds that I made. I beat the hell out of all three using a kinetic puller and can't get them to budge. I did full length resize them as I always do for this rifle. I then seated a bullet in a once fired winchester brass and tried to pull it; five smacks and out it came.

So I have two questions for you:
1. Do I have a die set up wrong or does factory new brass have very tight neck tensions? I do not believe that I'm applying any crimp.
2. If I go forward and make up a load ladder, will it be worth anything the next time around when these brass become once-fired? (Note, these are hunting rounds and I don't intend to do any annealing.)

Thanks!

[J-cat]

It's not just the tension. It's the additional friction caused by metal on metal contact between the case wall and the bullet. A fired case has carbon in the case wall. Carbon is like lube. A new case has no carbon. You get metal on metal and a lot more friction.

[NorCalNative]

J-cat, friction coefficient differences makes sense. Do you know if its enough to invalidate the results of a load ladder? I wonder what fps differences it makes?

[J-cat]

In my experience it will make a difference in point of impact, but not in average accuracy.

[gau17]

I run my brass thru a mandrel like this one. It helps remove dents, straighten the necks and make neck tension consistent.

http://www.21stcenturyshooting.com/3_8_Expander_Die_Body.php

[Whiterabbit]

It's not just the tension. It's the additional friction caused by metal on metal contact between the case wall and the bullet. A fired case has carbon in the case wall. Carbon is like lube. A new case has no carbon. You get metal on metal and a lot more friction.

The metal on metal contact between the case wall and the bullet IS "neck tension". One and the same.

OP, new brass being different than fired brass with respect to neck tension is a known phenomenon. If 1x shoots better than new, just make some plinkers and turn your new brass into 1x. You'll be GTG after that.