The Firing Line Forums - View Single Post - Neck sizing vs FL- bolt pros and cons

jepp2 · October 10, 2012, 04:38 PM

A few thoughts and questions for you:

Neck sizing:
- what type die are you going to use for neck sizing?
- If you use a Lee collet die, you will get the most concentric necks with the least amount of "work" sizing the neck
- If you use a full length sizing die and adjust it so it doesn't touch the shoulder, 2 things are going to happen. 1'st is the neck will be worked more due to a FL die reducing the neck beyond what is required and then the expander opens it up for proper bullet tension. 2'nd, the nature of a FL die will cause the shoulder to move forward from the body sizing that occurs as the die slides down the body. So you will have to bump the shoulder more often and either anneal the case necks or experience some loss due to splits.

FL sizing:
- do you know how to properly adjust the die so you only move back the shoulder the required amount? And if you follow the guidance of screwing the die in 1/4 turn after it contacts the shell holder, you don't know how to properly adjust your die.
- if you FL size and just move the shoulder the minimum amount, then the issues listed above (shorter neck life or required annealing) will apply.

What gives you the best accuracy in your rifle? Only you can tell for sure. But my experience would say your case life would be much greater if you use a collet die, and only bump the shoulder using a Redding body die when the shoulder needs to be moved back. But proper die set up is very important and if you aren't measuring how much you are moving the shoulder when you FL size, you can run into other issues.

October 10, 2012, 04:38 PM	#8
jepp2 Senior Member Join Date: December 24, 2008 Location: Loveland, CO Posts: 1,476	A few thoughts and questions for you: Neck sizing: - what type die are you going to use for neck sizing? - If you use a Lee collet die, you will get the most concentric necks with the least amount of "work" sizing the neck - If you use a full length sizing die and adjust it so it doesn't touch the shoulder, 2 things are going to happen. 1'st is the neck will be worked more due to a FL die reducing the neck beyond what is required and then the expander opens it up for proper bullet tension. 2'nd, the nature of a FL die will cause the shoulder to move forward from the body sizing that occurs as the die slides down the body. So you will have to bump the shoulder more often and either anneal the case necks or experience some loss due to splits. FL sizing: - do you know how to properly adjust the die so you only move back the shoulder the required amount? And if you follow the guidance of screwing the die in 1/4 turn after it contacts the shell holder, you don't know how to properly adjust your die. - if you FL size and just move the shoulder the minimum amount, then the issues listed above (shorter neck life or required annealing) will apply. What gives you the best accuracy in your rifle? Only you can tell for sure. But my experience would say your case life would be much greater if you use a collet die, and only bump the shoulder using a Redding body die when the shoulder needs to be moved back. But proper die set up is very important and if you aren't measuring how much you are moving the shoulder when you FL size, you can run into other issues.