Decision...Decision...30br turn or no turn neck

R

roe

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hello guys this is my first post on here might not be in right place I'm having a 30br built my smith has a .336 reamer this will be a no turn I don't know about it would like some imput on it this will be my first build as I'm new to the game Thanks Rick
 
I think that the issue of a no turn neck 30 BR has already been discussed, and in that discussion it was pointed that this may not be a practical approach for this particular caliber. The reason is that when a 6BR case is expanded up to .30 caliber, what was originally the top (front?) of the shoulder, which is much thicker, becomes the bottom (back?) of the neck. Someone correct me if I am wrong.
 
Boyd, I think this is not right. If you keep the same head clearance and shoulder angle, when you expand a case, the old neck/shoulder junction moves into the shoulder. But I too say correct me if I'm wrong.
 
I have made 30BR cases using two methods, either by necking them up, or blowing them out. Either method does produce a neck that is quite a bit thicker down where the shoulder neck junction meet. This means in a no neck turn situation, you will have a considerable "do-nut" at that spot.

Since you are going for a no neck turn, and accuracy doesn't seem to be the predominate reason for your choice, why not try to find some Remington 7BR cases to use as the parrent. Lots less metal to move, and the results might be more satisfactory......jackie
 
0879
roe....I would not do it, because the 6mmBR shoulder becomes part of the 30BR neck and has a definite taper from the thin mouth to the thick neck near the shoulder, and with the new "blue box" lapua 6BR brass this taper will be worse...I have a friend that has a "no neck turn" 30BR with a .334" neck...the brass has a lot to be desired with that taper in the neck wall...stick with the .330" neck for best results...IMO...have your gunsmith rent a reamer with a .330" neck and about .025" freebore so you can seat the bullet out long and get the 35+ grains of H4198 that is a very popular load...and go shoot some big score..:D

Eddie in Texas
 
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Good idea Jackie. The .30 cases made up from 7mm BR cases are a little shorter -- .015 or so, but that's small potatoes. R.G. Robinett, one of the grandfathers of the .30 BR, has won a lot of wood using 7mmBR brass.
 
The Remington 30AR looks pretty similar to the 30BR. How do case capacity and shoulder angle compare? If he doesn't want to turn necks maybe that would work. My experience has been that the RP brass can't with stand pressures like the Laupa, but you can run a 30BR pretty light and still get good performance. Tim

Edit- Just realized the boltface may not match..... I don't even know what a 30AR face is....???
 
eww1350 said:
0879
roe....I would not do it, because the 6mmBR shoulder becomes part of the 30BR neck and has a definite taper from the thin mouth to the thick neck near the shoulder, and with the new "blue box" lapua 6BR brass this taper will be worse...I have a friend that has a "no neck turn" 30BR with a .334" neck...the brass has a lot to be desired with that taper in the neck wall...stick with the .330" neck for best results...IMO...have your gunsmith rent a reamer with a .330" neck and about .025" freebore so you can seat the bullet out long and get the 35+ grains of H4198 that is a very popular load...and go shoot some big score..:D

Eddie in Texas
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Mostly I agree with Eddie especially on some freebore...

My reamer cuts a .030 freebore and a .334 Nk... After necking-up with mandrels I found the brass to be pretty ugly and needing "cleaned up".... Ranged from .3329 - .3340... Turned them all down to a consistent .332 with bullet... .002 clearence..
Works great and only a few thousands to cut in one pass.

Tim, stick with the Lapua brass..
cale
 
Rick ...

roe said:
hello guys this is my first post on here might not be in right place I'm having a 30br built my smith has a .336 reamer this will be a no turn I don't know about it would like some imput on it this will be my first build as I'm new to the game Thanks Rick
Click to expand...

Question: Decision...Decision...30br turn or no turn neck?

Answer: A .330" chamber with brass turned to .328".

READ THIS FIRST: http://www.6mmbr.com/30BR.html. Then ask yourself why all these winners didn't use a .336 reamer? What do they know that your smith doesn't? GO WITH WHAT WORKS! :)
 
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Charles,
You have it exactly backwards. When necking down, if the shoulder angle and location stays the same, the old neck shoulder junction moves into the shoulder. When necking up, which is what we are talking about to make a .30 Br from 6 BR brass, the original neck shoulder junction becomes part of the neck.
Boyd
 
Hello guys as I said I'm new in this I don't mind to turn the necks at all but my smith said he had a .336 reamer and I would not have to them sounded strange to me with all I've read and seen and the new brass being smaller I wanted some pro help thanks for everything I'm going with the .330 Rick
 
I can say from experience that it will help to go to at least a minimum turn neck. The difference is NOT night and day, but still isn't good enough. Brass necks just don't expand up concentrically(big word) enough to be good enough for competition. That said, if I didn't want to shoot competitively, and didn't want to turn necks, I would not be scared of a no-turn neck for informal use. I don't see the benefit of thin necks, but I do see the benefit of concentric necks.--Mike Ezell
 
Boyd Allen said:
Charles,
You have it exactly backwards.
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Ah. Be nice if it's the last time that happens. Not likely, though.

So much of my stuff is also shortened, with the shoulder pushed back. I always seem to have the old neck/shoulder seam in the middle of my new neck, no matter what. After the latest, greatest wildcat becomes a reality, factory chamberings start looking much better.

My .30 BR reamer is the Robinett design with the .330 neck, so I suppose I never looked before turning. But I don't remember seeing the usual ring of the old neck/shoulder junction. Time to clean the brass . . .

Anyway, thanks.
 
Boyd Allen said:
I think that the issue of a no turn neck 30 BR has already been discussed, and in that discussion it was pointed that this may not be a practical approach for this particular caliber. The reason is that when a 6BR case is expanded up to .30 caliber, what was originally the top (front?) of the shoulder, which is much thicker, becomes the bottom (back?) of the neck. Someone correct me if I am wrong.
Click to expand...

I also think so.

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The 30 AR is a fatter case than the 30 BR. Remington used the same dimentions as the 284 Winchester case at the butt. The case holds a bit mo powdah than the 30 BR, they won't interchange
 
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