Case neck tension ?

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If the bullets deforms or the case shaves the bullet when seated the neck is to tight.
I will disagree, if that happens to me it would be caused by my failure to expand the neck of the case. If I fail to align the bullet with the neck I would think the case would crush and if I did not correctly adjust the die off the crimp portion of the case I would get a bulge at the shoulder/case body juncture.

F. Guffey

We are talking about cases of the same length, correct? Right, if the die is not adjusted off the crimp shoulder the case will be bulged or set back into the shoulder at the neck/shoulder junction. Correct bullet alignment is necessary also chamfer on the inside of the case is also necessary as well as the outside. Proper neck expansion is also necessary. Lacking any of these things can result in bullet deformation or shaving or misalignment of the bullet. Any of these out of adjustment will have an adverse effect on accuracy.
 
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ok, what is amazing to me (and I completely believe it) is that the average .223/5.56 round generates 45,000-50,000 PSI. And we are talking about maybe 10 lbs of neck grip tension variation.
I think that underscores the precision involved in this whole contraption!
 
Went down that road with bushing dies, what worked best for me was the standard RCBS F/L die, nothing fancy. I take time with preping my brass. Clean brass with a wet tumbler with SS pins, clean the necks inside & out with 0000 steel wool, when I seat the bullet, it seats as smooth as butter. Had my bushing die at .002 neck tension,didn't seat as smooth as my standard die.

Very good. The standard die is what works for your rifle. What run-out are you getting?
 
To much neck Tension does not always mean lack of accuracy by no means. One would just have to work up another load that it shoots accurate at. You will never crimp or have so much tension that your gun would blow up. Before I got my dies honed to .002 is was seating with very good ( tight ) neck tension. If and I say If you are shooting BT bullets and you Chamfer the inside neck, you will never scrap a bullet or deform it in any way. The brass neck WILL expand no matter what. It's just that .002 neck tension is an Ideal set up for most rifles, it does not mean you have to be at that setting.
 
Lee, my runout with the bushing die was an average of.003 with the F/L standard die .001 that's with the expander ball, though I leave the shaft of the expander with a little play but not loose. Works for me, also I keep my headspace at .001 & trim case neck every reload to 2.012 on 308 cal
 
I think that underscores the precision involved in this whole contraption!
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I agree.

I believe a contraptions would be a devise, a philosophy is 'what someone thinks'. Someone should sit down and determine what factors are involved. Two factors involved should include time and speed.

Most reloaders should go out and purchase R. Lee's book on modern reloading. He has a small section that covers crimping. And, he ventures into the difference it makes, or does not make.

Again, I want all the bullet hold I can get, it is possible crimping can lesson bullet hold.

F. Guffey
 
I had believed that 223 only needed to be trimmed after the first shooting, before the first reloading. That is why I was surprised to see they were so long and that was after FL sizing.
I have a possum hollow trimmer that goes in my cordless drill. The case goes into the trimmer and trims from the shoulder of the case. It is adjustable also so you get the exact length. It does a great job of trimming them all to the same length.
 
223 rem trim length

I decided to check the length and found them almost all over length some as much as 1.785, they should be 1.750. Some are as much as .030 over.
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Trim length, after sizing is 1.760" maximum. Trim to is 1.750" When the length gets longer than 1.760" there is a possibility that the bullet will get crimped into the case by the chamber. This will increase pressure and may damage the rifle or shooter. There is a "safety zone" built into the chamber that lets long brass still be safe. But its never good to use the "safety zone" http://www.saami.org/PubResources/CC_Drawings/Rifle/223%20Remington.pdf
 
Trim length, after sizing is 1.760" maximum.
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I have heard that before, I do not agree. A few reloaders understand there is case trimming when set up on the shoulder then there is measuring the length of the case from the end of the neck to the case head. For reloaders like me that keep up with the length of the chamber from the shoulder/datum to the bolt face find a conflict when trimming cases to length with total disregard for the length of the chamber, again, from the shoulder to the bolt face.

I have one chamber that is .002" longer than a field reject length gage. When sizing/forming I add .014" to the length of the case from the mouth of the neck to the case head.

I know, that is not multi-tasking but it is should come close to 'simply keeping up'.

F. Guffey
 
F. Guffey, they made the Giraud just for you. The Giraud trimmer indexes of the case shoulder rather than the case head. :D
 
http://www.matchprep.com/

I have the Gracey, I also have forming/trim dies. There are not many Lee type trimmers I do not have. I also have case trimmers that were designed to trim before sizing, and I have trimmers that were designed to force the reloader to go into mortal combat when removing the case neck from the pilot.

F. Guffey
 
"I have one chamber that is .002" longer than a field reject length gage. When sizing/forming I add .014" to the length of the case from the mouth of the neck to the case h"

You have a chamber with .014" headspace? That is .014" from the case head to the datum line? You can stretch the case that much without a head separation?
 
Lee, my runout with the bushing die was an average of.003 with the F/L standard die .001 that's with the expander ball, though I leave the shaft of the expander with a little play but not loose. Works for me, also I keep my headspace at .001 & trim case neck every reload to 2.012 on 308 cal


CW 308,
Your going to keep that die, right?!?! Sounds like it's working very well for you. Leaving the expander shaft a little loose works. I put an "O" ring under the nut on the shaft and tighten it hand tight.
 
Lee, we think the same.I use a O- ring between two washers on the shaft , also a 7/8 x 1/8 O - ring under the lock ring will take up any slack in the threads & fine tune the die for headspace, also makes it easier to remove the die when finished. The competition shell holders a set of 5 from Redding used with my standard RCBS F/L die work great for me.
 
cw308,
Yes we do think along the same lines. I use a 7/8" "O" ring also on my 6.5x06 dies as well as 308. I have the Redding shell holder kit for 223 haven't got a set for 308 yet.
 
You have a chamber with .014" headspace? That is .014" from the case head to the datum line? You can stretch the case that much without a head separation?
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Yes I can, I do. I form 280 Rmeington cases to 30/06. The 280 R. case is longer from the shoulder to the case haed than the 30/06 by .051". When forming the long cases I adjust the die off the shell holder .014". That gives gives me the magic .002" clearence.

I have a 30/06 forming die that needs to go back to RCBS, I could call and expalin to them what happen but all they want is the die.

F. Guffey

You have a chamber with .014" headspace?
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No, I have clearence. Head space is the length of the chamber from the datum to the bolt face. I have 'extra head space'.
 
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You have a chamber with .014" headspace? That is .014" from the case head to the datum line? You can stretch the case that much without a head separation?
Yes I can, I do. I form 280 Rmeington cases to 30/06. The 280 R. case is longer from the shoulder to the case haed than the 30/06 by .051". When forming the long cases I adjust the die off the shell holder .014". That gives gives me the magic .002" clearence.

I have a 30/06 forming die that needs to go back to RCBS, I could call and expalin to them what happen but all they want is the die.

F. Guffey

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You have a chamber with .014" headspace?
No, I have clearence. Head space is the length of the chamber from the datum to the bolt face. I have 'extra head space'.

Your making 06 from 280 to compensate for a chamber with .012"-.014" headspace, a lot of work. If there are no sights on the barrel why not set it back the amount of headspace and save the trouble? Or set it back a full turn to bring the sights up and rechamber to the correct headspace? What rifle are we talking about?
 
Again, the rifle does not have .014” head space it has a chamber that is .011” longer than a go-gage length chamber, or .002” longer than a field reject length chamber.

The chamber in this rifle is not unusual; I have applied the ‘leaver policy’ to it. I am going to leaver the way I founder. If I removed the barrel it would go back to together with a heavy bench rest type barrel.

F. Guffey
 
If there are no sights on the barrel why not set it back the amount of headspace and save the trouble?
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Trouble for who? I am a reloader/case former, my dies and presses have threads. Threads make my dies adjustable to, or off or below contact with the shell holder.

Then there is that thing about head space, one more time; I have no infatuation with head space. In the old days the story started with: “Hatcher said etc...” Problem, I did not agree with Hatcher or everyone else failed to understand what he said.

You are assuming the cases stretch .016” the first time they are fired. You are assuming the firing pin (as slow as it travels) drives the case to the shoulder of the chamber, and then?

I have purchases thousands of fired cases from firing ranges, 7 to 10 cents each is a bargain for once fired cases, plus they always thrown in an additional 10 just in case. I use the length of the case to off set the length of the chamber. That is easy to manage when the case is longer from the shoulder to the case head than the chamber form the shoulder to the bolt face.

What to do with the long chamber? I could cut the chamber to 30/ Gibbs. There is a problem with the 30 Gibbs, it has a short neck. The 30 Gibbs neck measures .217” long from the shoulder/neck juncture to the end of the neck. That is not a problem for me, I add to the length of the neck in the chamber.

Back to where we started. The 30 Gibbs case shortens .045” from start to finishing when forming and firing. ‘I fixed that’, I start with longer cases.

F. Guffey
 
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If there are no sights on the barrel why not set it back the amount of headspace and save the trouble?

Trouble for who? I am a reloader/case former, my dies and presses have threads. Threads make my dies adjustable to, or off or below contact with the shell holder.

Then there is that thing about head space, one more time; I have no infatuation with head space. In the old days the story started with: “Hatcher said etc...” Problem, I did not agree with Hatcher or everyone else failed to understand what he said.

You are assuming the cases stretch .016” the first time they are fired. You are assuming the firing pin (as slow as it travels) drives the case to the shoulder of the chamber, and then?

I have purchases thousands of fired cases from firing ranges, 7 to 10 cents each is a bargain for once fired cases, plus they always thrown in an additional 10 just in case. I use the length of the case to off set the length of the chamber. That is easy to manage when the case is longer from the shoulder to the case head than the chamber form the shoulder to the bolt face.

What to do with the long chamber? I could cut the chamber to 30/ Gibbs. There is a problem with the 30 Gibbs, it has a short neck. The 30 Gibbs neck measures .217” long from the shoulder/neck juncture to the end of the neck. That is not a problem for me, I add to the length of the neck in the chamber.

Back to where we started. The 30 Gibbs case shortens .045” from start to finishing when forming and firing. ‘I fixed that’, I start with longer cases.

F. Guffey

Me to, and my presses and dies have as many threads as yours.

True, if you start with longer brass you can set the headspace as you wish.

Using 280 brass to make 06 cases for a rifle with headspace seems a lot of trouble considering sizing, expanding, fire-forming, and the like. An hour on the lathe and your back to using 280 brass for 280.

What EXACTLY is the measurement from the bolt face to the datum line in the chamber?

I've read Hatcher.
 
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