Neck sizing

[J-cat]

Are you denying that the bolt becomes increasingly harder to close with each reload on neck sized brass?

[J-cat]

Not unless the lugs are dry (no lube) and a little grit is introduced.
The lugs in a bolt rifle have lots of camming power to make a case fit.
As long as you keep them lubed, they can handle tight cases easier than they handle the explosion of the powder burn squirting the bullet out of the barrel.

For 2 maybe 3 reloads.

[fguffey]

Are you denying that the bolt becomes increasingly harder to close with each reload on neck sized brass?

I could say I have neve known of a group of people that are as desperate for attentions as reloaders; no one remembers the claim the claim reloaders made when starting over. The old saying went something like: When neck sizing the reloaders must start over by full length sizing after the 5 firing because by the 5 firing the case is full grown. I asked every time; how is it possible to start over by full length sizing? The case has been fired at least 5 times. Not one of the reloaders making up that silly saying considered ever time the case was fired the ability of the case to be sized increased.

I had more confidence in the reloader than most had in themselves, I insisted the reloader had the ability to determine the length of the chamber from the shoulder to the bolt face and I insisted the reloader could transfer that measurement to the press, die and shell holder. From that day to this they have proven to me I should have never put that much confidence in a reloader that is desperate for attention.

I had some time so I went to a big gun store in and or near Long Beach; I asked the person behind the counter if I would be allowed to see an M1 Grand in the rack behind him. He obliged, he went through the 'order of arms' and then handed me the rifle. After he handed me the rifle I asked to see his fine ball point. He handed me his fancy ball point; and then? I stuck the pen into the M1 rifle with the open rifle. And then? Wouldn't you know it, the bolt closed and crushed his very nice pen. It was then I handed him the rifle back with the pen protruding out of the top. It was one of those moments' you could have heard a pin drop. And then there was that time down in Fort Hood, Texas, the shooter next to me allowed the bolt to close on his thumb. He went into shock; jumping up and down and flawing his arm around with the rifle locked to his thumb. Up to that point in time I did not believe in hypnotics. After that day I could not get anyone to volunteer.

F. Guffey

[fguffey]

I went to my 'go to gun parts store' looking for gun parts; while waiting a customer was wanting the length of his chamber checked from the shoulder to the bolt face. The owner/smith informed the customer he could not check the head space on the very fine and exotic rifle because he did not have a go-gage for the chamber. the would be customer was disappointed but the answer was no.

I did not get involved; when the customer left I told the owner/smith I could check the head space three different ways without a head space gage. No one in the building said 'BS', The owner showed a lot of class when he asked, "HOW?" !

Allow me to check 'things' you have in your displays, cabinets and hanging one the walls. In less than one minute I had what I needed. When I finished the owner/smith said, "Well I'LL be Dammed". I did mention I have grinders that make piolets, grind angles and grind to length, I suggested others believe head space gages are made on mars.

And we have a common friend, he has no fewer than 20 30/06 head space gages, he complained to me he did not have a head space that that would measure the actual length of the chamber from the shoulder to the bolt face. I informed him I measure the actual length of the chamber from the shoulder of the chamber to the bolt face without a head space gage, Head space gages do not lock me up.

F. Guffey

[ar15barrels]

I went to my 'go to gun parts store' looking for gun parts; while waiting a customer was wanting the length of his chamber checked from the shoulder to the bolt face. The owner/smith informed the customer he could not check the head space on the very fine and exotic rifle because he did not have a go-gage for the chamber. the would be customer was disappointed but the answer was no.

I did not get involved; when the customer left I told the owner/smith I could check the head space three different ways without a head space gage. No one in the building said 'BS', The owner showed a lot of class when he asked, "HOW?" !

Allow me to check 'things' you have in your displays, cabinets and hanging one the walls. In less than one minute I had what I needed. When I finished the owner/smith said, "Well I'LL be Dammed".

Someday, you should explain how to do this instead of just bragging that you can do it.
We call that teaching.
Other people might also find that knowledge that you possess to be useful knowledge.

[JagerDog]

Are you denying that the bolt becomes increasingly harder to close with each reload on neck sized brass?

How does the case get larger than it's container?

[ar15barrels]

How does the case get larger than it's container?

The container expands from the pressure that squirts the bullet out of the barrel and then contracts after the pressure subsides.
The case yields (permanent deformation) while the container only deflects (temporary deformation that goes away after the pressure goes away).

This difference in yield strength of the materials is what allows cases to grow larger than their containers.

[fguffey]

Not one of the reloaders making up that silly saying considered ever time the case was fired the ability of the case to be sized increased.

How does the case get larger than it's container?

In there silly saying they claim it is necessary to start over, and I ask: How is it possible to start over after the case has been fired 5 times? I am beginning to believe reloading is not for everyone; especially for those that are desperate for attentions.

I have fired cases once, after firing once the cases were almost impossible to remove from the chamber, the case head increased in diameter, the flash hole increased in diameter, the primer pocket hole increased in diameter and the case head shortened from the cup above web to the case head.

And then there are cases that are difficult to push into the shell holder. The case fit the shell holder when sized but not after firing.

I understand; you are so confused. But I have shell holders that I have had for 40+ years, they are different. The fact they are different does not drive me to the curb. But when I load a round, fire it and then find it will not fit the original shell holder I reach for a ball peen/gasket cutting hammer or change shell holders/ or presses.

F. Guffey

[JagerDog]

The container expands from the pressure that squirts the bullet out of the barrel and then contracts after the pressure subsides.
The case yields (permanent deformation) while the container only deflects (temporary deformation that goes away after the pressure goes away).

This difference in yield strength of the materials is what allows cases to grow larger than their containers.

Yes, I meant to say progressively/incrementally (diminishing clearance and ultimate negative clearance with successive firings).

The case acts as a malleable sealing gasket upon firing. It's going to expand to the maximum dimensions of the chamber. That takes place regardless of initial clearance (providing there's ample interior pressure).

[God Bless America]

Someday, you should explain how to do this instead of just bragging that you can do it.
We call that teaching.
Other people might also find that knowledge that you possess to be useful knowledge.

Fguffey is uniquely qualified

[ar15barrels]

Yes, I meant to say progressively/incrementally (diminishing clearance and ultimate negative clearance with successive firings).

The case acts as a malleable sealing gasket upon firing.
It's going to expand to the maximum dimensions of the chamber. That takes place regardless of initial clearance (providing there's ample interior pressure).

So when the case fills the chamber, you have BOTH deflection and plastic deformation.
The plastic deformation is the part of the expansion that is permanent.
The deflection is temporary and is why the cases can be removed from the chamber after firing.

Plastic deformation is reduced by deflection.
The more room you have to deflect BEFORE the plastic deformation threshold is reached, the less plastic deformation you will have.
At normal operating pressures, the case will continually getting plastic deformation on every firing and the case will get a little bit larger at each firing until it's fully resized again.

To put some numbers to this for demonstration, lets say we have full length sized a case and have 0.004" of clearance between case and chamber and we had 25% of deflection in the brass before the brass started plastically deforming.
So we apply pressure and the case stretches 0.001" and then deforms the final 0.003" to fill the 0.004" clearance.
Then the pressure goes away as the bullet leaves the bore.
Now that 0.001" of deflection goes away and the case can be extracted from the chamber.
In this scenario, the plastic deformation was 75% of the size change per firing and the deflection was 25%.

Now lets neck size that cartridge and fire it a 2nd time.
This time, we now only have 0.001" of clearance to start.
So we give 25% of that clearance to deflection and 75% to plastic deformation.
Now our case has expanded another 3/4 of a thousandth, leaving us just 1/4 of a thousandth of clearance in the chamber.

Now lets neck size that cartridge and fire it a 3rd time.
This time, we now only have 0.00025" of clearance to start.
That's 25 microns.
So we give 25% of that clearance to deflection and 75% to plastic deformation.
Now our case has expanded another 3/4 of 0.00025", leaving us 0.0000625" of clearance in the chamber after the 3rd firing.
That's 6 microns.
No surprise that the case will not fit into the chamber so easily after the 3rd firing while only being neck sized.

The operating pressure will change the percentage of deflection vs elongation.
At lower operating pressure, you get more deflection (by percentage) and less plastic deformation.
This means you can go more neck-sized firings between full length resizings before you have a fit problem.

Now lets remember that the chamber will be expanded and larger than it's static diameter while the pressure is applied.
That additional diameter makes room for the case to plastically deform beyond the static diameter of the chamber.
This will be the point where the cases will no longer chamber freely.

[JagerDog]

So when the case fills the chamber, you have BOTH deflection and plastic deformation.
The plastic deformation is the part of the expansion that is permanent.
The deflection is temporary and is why the cases can be removed from the chamber after firing.

Plastic deformation is reduced by deflection.
The more room you have to deflect BEFORE the plastic deformation threshold is reached, the less plastic deformation you will have.
At normal operating pressures, the case will continually getting plastic deformation on every firing and the case will get a little bit larger at each firing until it's fully resized again.

To put some numbers to this for demonstration, lets say we have full length sized a case and have 0.004" of clearance between case and chamber and we had 25% of deflection in the brass before the brass started plastically deforming.
So we apply pressure and the case stretches 0.001" and then deforms the final 0.003" to fill the 0.004" clearance.
Then the pressure goes away as the bullet leaves the bore.
Now that 0.001" of deflection goes away and the case can be extracted from the chamber.
In this scenario, the plastic deformation was 75% of the size change per firing and the deflection was 25%.

Now lets neck size that cartridge and fire it a 2nd time.
This time, we now only have 0.001" of clearance to start.
So we give 25% of that clearance to deflection and 75% to plastic deformation.
Now our case has expanded another 3/4 of a thousandth, leaving us just 1/4 of a thousandth of clearance in the chamber.

Now lets neck size that cartridge and fire it a 3rd time.
This time, we now only have 0.00025" of clearance to start.
That's 25 microns.
So we give 25% of that clearance to deflection and 75% to plastic deformation.
Now our case has expanded another 3/4 of 0.00025", leaving us 0.0000625" of clearance in the chamber after the 3rd firing.
That's 6 microns.
No surprise that the case will not fit into the chamber so easily after the 3rd firing while only being neck sized.

The operating pressure will change the percentage of deflection vs elongation.
At lower operating pressure, you get more deflection (by percentage) and less plastic deformation.
This means you can go more neck-sized firings between full length resizings before you have a fit problem.

Now lets remember that the chamber will be expanded and larger than it's static diameter while the pressure is applied.
That additional diameter makes room for the case to plastically deform beyond the static diameter of the chamber.
This will be the point where the cases will no longer chamber freely.

I follow the logic. I've tested (to failure and not) a lot of materials in free space. I question whether that deflection and deformation ratio remains constant when it has say 0.004 to move vs. 0.001 to move.

The chamber is exerting an equal force on the case while under pressure (while acting as a gasket).

[Bumslie]

To each their own.

Sent from my SM-N950U using Tapatalk

[LynnJr]

I make datums I use datums and I know datums. Datums don't kick me to the curb.
Then there was the time I went to the store and the customer wanted to buy datums. The guy behind the counter didn't have any datums handy but I bit my lip.
Yes I just happened to have my pockets full of datums as datums don't curb me.
Then was the time I needed some tensions. Tensions like datums don't curb me. I needed tensions and was willing to trade but the guy behind the counter didn't need datums.
I ended up getting my tensions but getting them wasn't easy.
I was forced to clean a crushed pen out of a M1 chamber to get those tensions but of course tensions don't curb me.
Please curb your dog but know (fool) well you won't curb me over datums or tensions.
And then there was the time I was fireforming.
When fireforming with feeler gages datums don't curb me. I have lots of datums but could use some more tensions.

[highpower790]

I make datums I use datums and I know datums. Datums don't kick me to the curb.
Then there was the time I went to the store and the customer wanted to buy datums. The guy behind the counter didn't have any datums handy but I bit my lip.
Yes I just happened to have my pockets full of datums as datums don't curb me.
Then was the time I needed some tensions. Tensions like datums don't curb me. I needed tensions and was willing to trade but the guy behind the counter didn't need datums.
I ended up getting my tensions but getting them wasn't easy.
I was forced to clean a crushed pen out of a M1 chamber to get those tensions but of course tensions don't curb me.
Please curb your dog but know (fool) well you won't curb me over datums or tensions.
And then there was the time I was fireforming.
When fireforming with feeler gages datums don't curb me. I have lots of datums but could use some more tensions.

Dr. Suess reincarnated!Well played.