How far to turn new brass?

T

tiny68

Member
I am making my first 30BR brass. My original barrel came with a lot of brass. New barrel is a 0.330 neck. I expanded new brass to 30 cal with a tapped button. I turned the first lot to 0.011" thickness. It turned all the way down to the neck-shoulder junction. When I was talking to someone at a recent match, they said I needed to fire-form first to know exactly were the shoulder-neck junction will be. I am in a egg-before-the-chicken dilemma.

How do you guys know how far to turn up the neck?:confused::confused::confused:

Thanks,

Tiny
 
How far?

It is ok to just touch the shoulder with the neck turning cutter. That area will blow out to actually be a part of the shoulder upon fireforming....just don't cut deeply into the shoulder. In addition, this will get rid of any constriction at the neck shoulder juncture.....also known as the "dreaded donut."

Most case turning tools have a relief angle on the leading edge to help clear the shoulder. Of course, if you are using a lathe, you will probably grind your own cutting tool and can put in whatever relief that you feel is best.
 
Tiny

Most of the 30br chambers are so close to the parent case that even though it will change after fireforming, it isn't changing enough to worry if you turn to the neck shoulder junction. You should have found that when you mechanically expanded to the 30 from the 6, part of the 6 shoulder turns into the 30's neck. That juncture doesn't seem to move upon fireforming and some people actually fireform during a match, because not much energy is lost in the fireforming process. Randy J.
 
Thanks all....

... for your comments. I will load up you loads and try out the new barrel this weekend. I have only made 50 brass at this point but it sounds like I did it right. I think I will not anneal after turning on this first set. I want to keep it as simple as possible.

Tiny
 
6 BR 30 BR Parent Case

I am going to be making 30 BR brass. This will be made out of Lapua 6 BR brass. I have never loaded for the 6 BR. Does the parent case head actually read "Lapua 6mm BR Norma"? Sinclair says it is the right one and the case length has to be cut back.

Jeffrey Tooker
 
Jeffreytooker said:
I am going to be making 30 BR brass. This will be made out of Lapua 6 BR brass. I have never loaded for the 6 BR. Does the parent case head actually read "Lapua 6mm BR Norma"? Sinclair says it is the right one and the case length has to be cut back.

Jeffrey Tooker
Click to expand...

Yes

Dick
 
Tiny ...

tiny68 said:
I am making my first 30BR brass. My original barrel came with a lot of brass. New barrel is a 0.330 neck. I expanded new brass to 30 cal with a tapped button. I turned the first lot to 0.011" thickness. It turned all the way down to the neck-shoulder junction. When I was talking to someone at a recent match, they said I needed to fire-form first to know exactly were the shoulder-neck junction will be. I am in a egg-before-the-chicken dilemma. How do you guys know how far to turn up the neck? :confused::confused::confused: Thanks, Tiny
Click to expand...

This just might help answer some of your questions. Good stuff: http://accurateshooter.wordpress.co...-your-cutter-angle-for-improved-neck-turning/
 
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