neck diameter ?

[fguffey]

I received a call from a man that builds bench rest type rifles; he said the owner of one of his rifles was complaining about the chamber. He said the owner said the neck was too large in diameter. I asked about accuracy; he said there was no complaint about accuracy.

I boxed up a few tools and went for a visit. We sorted through boxes and boxes of cases and settled on LC National Match 30/06 cases. I formed the 30/06 cases to 308 W and then sized the cases to off set the length of the chamber. When finished the formed cases reduced the clearance between the chamber neck and outside diameter of the case neck to .003”. I cautioned him about forming cases with thicker case bodies meaning going through the motions of case forming with different cases will not guarantee the desired clearance. We formed 200 cases.


F. Guffey

 

[waldo1979]

What is the neck thickness of your brass?

.333 Outside Diameter neck
.308 bullet
------
.025 / 2 = 0.012.5"

Thats a very thin neck.

 

[blvedere]

If you're chamber really has a .348" neck, your fired brass neck will measure .3465"-.347" and someone owes you a new barrel.

You should start a different thread.

 

[blvedere]

My fired brass mikes out at 0.344/0.345. I understand Cerrosafe shrinks a little, but casting mikes out at 0.348. Also,didn't mean to hijack atlati's thread. Thanks

 

[Brians356]

My 30-06 cases have neck walls 15.5" to 16.0" thick. Cartridges in this size class don't have un-turned neck walls as thin as .012" in my experience, that's getting down into 223 territory. If your necks were even 14" thick, the die would be working fine.

Also, some Redding FL dies have slightly larger neck IDs than the typical RCBS, Lee, etc dies. Redding's approach is to reduce neck sizing somewhat for standard brass, within reason. I have an old Lyman FL die with a neck ID of only .324". My guess is that your Redding's is about .331 or .332.
-

 

[atlatl]

My 30-06 cases have neck walls 15.5" to 16.0" thick. Cartridges in this size class don't have un-turned neck walls as thin as .012" in my experience, that's getting down into 223 territory. If your necks were even 14" thick, the die would be working fine.

Also, some Redding FL dies have slightly larger neck IDs than the typical RCBS, Lee, etc dies. Redding's approach is to reduce neck sizing somewhat for standard brass, within reason. I have an old Lyman FL die with a neck ID of only .324". My guess is that your Redding's is about .331 or .332.
-

My Redding die is .331-.332 which is exactly the problem. .012+.012+.308= .332 which results in nearly no neck tension using the brass I have.

 

[Brians356]

My Redding die is .331-.332 which is exactly the problem. .012+.012+.308= .332 which results in nearly no neck tension using the brass I have.

Several of us have mentioned your thin case necks (for 30-06). What brand of brass do you have, and is it new unfired, or stuff you acquired second hand?
-

 

[fguffey]

My Redding die is .331-.332 which is exactly the problem. .012+.012+.308= .332 which results in nearly no neck tension using the brass I have

Neck tension: How to solve a neck tension problem? Neck tension is not solved with tension because the reloader can not measure tension and I do not have a conversion chart that converts tensions to pounds. I guess saying 'tension' is like one of those feel good words, It is one of those words that makes a reloader feel like they know what they are talking about. My opinion? Tension is the wrong standard, that is the same thing as describing the color blue as 3 feet long.

If the OP wants help he is must determine the diameter of the neck in the chamber and the outside diameter of the case neck with a seated bullet. When my friend called wanting help with his chamber dimensions and trying to determine why he had one man complaining about something that die not effect accuracy; I suggested he was dealing with an Internet reloader and or someone that wanted his brass to last forever by working it less. There was nothing the builder could do about improving accuracy, there was something I could do to reduce the clearance between the neck of the case and chamber.

F. Guffey

 

[fguffey]

My fired brass mikes out at 0.344/0.345. I understand Cerrosafe shrinks a little, but casting mikes out at 0.348. Also, didn't mean to hijack atlati's thread. Thanks

Belvedere, what rifle? Turning necks and reaming the inside of the neck keeps a reloader busy, and then: (always, there is a ' and then') there is learning to deal with what you have when turning and reaming will not increase the thickness of the case neck. Me? ‘No problem' all other reloaders move the shoulder, I find that impossible with out crushing the case body so I form another shoulder on a case that is longer from the shoulder to the case head; this allows me to use the thicker case body to off set 'loose necks'.

Most difficult to comprehend is the forming of 308W cases from 30/06 cases. In the perfect world forming a 30/06 case to 308 W and then load the case for 308 W will render your rifle scrap. Or I should say it is possible the case neck will be so tight in the chamber there is no room for neck expansion. We all know the bullets must get out of the way but a tight neck could delay that.

And then; the delay is not something that can be discussed.


F. Guffey

 

[atlatl]

Several of us have mentioned your thin case necks (for 30-06). What brand of brass do you have, and is it new unfired, or stuff you acquired second hand?
-

I believe that the thread has been derailed by another question or topic to which Mr Guffey is replying. My brass is unusually thin, it is Winchester brass purchased new by me, not ever neck turned. Fired 2-3 times and annealed. My rifle's chamber neck is .339-.340. Thicker necked brass or a bushing die appear to be my best solutions.

Thank you for the replies.

 

[fguffey]

Could someone please suggest what the appropriate neck diameter should be for a 30'06 full length sizer die? Sizing brass in my Redding die,without the expander ball, gives an outside diameter of .333. This results in almost no neck tension using Winchester brass, which as best as I can determine has a wall thickness of .012.

That leaves you with no neck tension? I have tensions gages, none of my tension gages measure tension.

When you remove the sizing ball assemble from the die you are on your own. I size cases with the full a length sizing die; if I remove the sizing plug from the die I can not seat a bullet because the hole in the neck is too small for the bullet unless I use pointed base bullets.. And then; I believe it is so nice the manufacturer designed the die to expand the neck when the ram is lowered, it is almost a no brainier. In the old days when reloaders did not like the inside diameter of the neck after pulling the sizing ball through the neck they would grind the sizing die. And then, there were others that contacted the company that manufactured the die for smaller diameter neck expanders.

And then we have to consider there is a big chance there are reloaders that spend more time talking about reloading than they spend actually reloading.

F. Guffey

 

[ireload2]

Please tell us how to grind a sizing die if we do not like the inside diameter of the neck.

That leaves you with no neck tension? I have tensions gages, none of my tension gages measure tension.

When you remove the sizing ball assemble from the die you are on your own. I size cases with the full a length sizing die; if I remove the sizing plug from the die I can not seat a bullet because the hole in the neck is too small for the bullet unless I use pointed base bullets.. And then; I believe it is so nice the manufacturer designed the die to expand the neck when the ram is lowered, it is almost a no brainier. In the old days when reloaders did not like the inside diameter of the neck after pulling the sizing ball through the neck they would grind the sizing die. And then, there were others that contacted the company that manufactured the die for smaller diameter neck expanders.

And then we have to consider there is a big chance there are reloaders that spend more time talking about reloading than they spend actually reloading.

F. Guffey

 

[Twoboxer]

Could someone please suggest what the appropriate neck diameter should be for a 30'06 full length sizer die? Sizing brass in my Redding die,without the expander ball, gives an outside diameter of .333. This results in almost no neck tension using Winchester brass, which as best as I can determine has a wall thickness of .012.

Don't know how chamber size could possibly enter into an answer to your question.

Just had a similar measuring experience with tonight's 30-06 loads . . . numbers similar to your report. Got even more concerned when I measured 20 Sierra 175gr TMKs and found they ALL were EXACTLY .3075.

So I took one of my resized cases with its obviously over-sized neck ID and one of my bullets with its obviously under-sized OD, and tried to hand force the bullet into the case. It would not go in.

I concluded I didn't have a neck tension problem, I had a measurement problem.

Just a thought

 

[dcali]

Recently purchased a 30 cal 308 McGowen barrel on line. I have been having trouble making it shoot the way I want, 600 yards. Had a chamber cast made and found that the chamber neck was 0.348" and my loaded round was 0.333". Other than over working my brass do you, as I do, think this is effecting my load development. I have my own answers just want some other feedback. Thanks

This is no good - it's basically max SAAMI, maybe a hair over. Your brass will not be happy.

 

[fguffey]

Other than over working my brass do you, as I do, think this is effecting my load development. I have my own answers just want some other feedback

I would use a case with a thicker case neck, you neck in your chamber reminds me of military chambers with generous necks

F. Guffey.