How to bump back the shoulder

[F. Guffey]

I thought all along your die was set up with the die bottoming on the shellholder , Sorry . How is your accuracy with neck sizing and after full sizing .

Not me, not my dies: I have no problem using a full length sizing die for neck sizing. I use very simple rules when using the full length sizing die for neck sizing. I adjust the de off the shell holder; is have used a feeler gage to adjust the die off the shell holder to prevent the body of the case from being sized. A reloader with a little shop skill should not have trouble determining how far the die is adjusted down to start the die from sizing the case body. And then there is the advantage of partially sizing the neck as in leaving part of the neck upsized' they say the unisized portion of the neck that is not sized helps center the case.

And then there is that 'saying', after neck sizing 4 times the reloader must start over by full length sizing and I ask how is it possible to start over if the case had been fired 5 times?

F. Guffey

 

[F. Guffey]

How to bump back the shoulder

It is not possible to bump the shoulder back; I am the only reloader that can reduce the length of the case from the datum to the case head without bumping the shoulder back because I am the only reloader that understands the shoulder I finish with is not the same shoulder I started with.

It believe it is easier for me because my cases do not have head space; my cases do not have head space because SAAMI does not use the head space symbol in their case drawings. I off set the length of the chamber from the shoulder of the chamber to the bolt face with the length of the case from the shoulder to the case head.

Years ago I suggested reloader scribe the case at the case body/shoulder juncture when trying to determine what happens to the case when sized. I even suggested that is what Hatcher should have done when he was trying to work out problems with case head separation. He was convinced a chamber that was .060"+ was to long for a short case that was .060" shorter from the case shoulder to the case head than the chamber from the shoulder of the bolt face. Had he scrivewd the case body/shoulder juncture he would have know what happen the shoulder of the case when fired and when sized. AND! then there was the length of the neck.

And there were other factors, he could have eliminated a few, not all 03s were alike.

F. Guffey

 

[RedSkyFarm]

Cw308. I thought I was bottomed out. I was not. The ram was at the top of the stroke and I ASSUMED (we all know what that gets us!) that I was bottomed out. After getting the feeler gauges out, I discovered I wasn’t. Then made adjustments from there. As far as neck sizing, I initially with new brass would run all through the FLS die before loading. Then neck size the fired brass from that point. Neck sizing was more accurate in my case. I have a chamber that is .003-.004” longer than an unfired case. So now that I know how to properly full length size a piece of brass, I will see what the difference between the two are. That has yet to be determined. I’ll give an update as soon as I fire some and find out.

 

[F. Guffey]

I have a chamber that is .003-.004” longer than an unfired case.

If I had one of those I would have a short chamber because we all know the chamber is reamed to go-gage length and the case is sized to minimum length/full length sized.

What does that mean? If you placed a .003" feeler gage between the deck of the shell holder and case head you would eliminate the clearance between the shoulder of the case and shoulder of the chamber.

And then there is that part about determining the winner; if the die makes it down to the top of the shell holder with zero clearance the press wins. If there is clearance between the bottom of the die and top of the shell holder the case wins; MEANING! the case has more resistance to sizing than the press can overcome.

F. Guffey

 

[HiBC]

A case being sized down in diameter by a FL sizing die is supported,at least on the outside.

Aside from some silly word puzzle argument,if a case is checked in an RCBS Precission Mic or a bushing type "Cartridge headspace gauge" .(As the manufacturer calls them)

And if I run it through the FL sizer die and it comes into spec,the case head to shoulder datum length has been reduced.

That's the desired result,Mr Guffey.All the rest of the reloaders(except you) call that bumping or setting the shoulder back.

Apparently you are the "Only Reloader" who cannot perform the shoulder adjustment that the rest of the reloaders have been doing since FL sizing dies have been produced.

One more thing: I agree with using technically correct language. What brief,technically correct ,reasonably universally understood terminology do you have to offer to describe the measurement of the cartridge brass from the case head to the datum feature that contacts the firearm chamber headspacing feature? In other words,what do YOU have to offer instead of the often used (FOR LACK OF A BETTER TERM) "Cartridge Headspace"

If you do not have such a term to offer,why don't you stop obstructing and confusing and making it harder to answer questions?

 

[hounddawg]

A case being sized down in diameter by a FL sizing die is supported,at least on the outside.

Aside from some silly word puzzle argument,if a case is checked in an RCBS Precission Mic or a bushing type "Case headspace gauge" as the manufacturer calls them....
If this case shows the "case headspace" is .004 out of spec,long,

And if I run it through the FL sizer die and it comes into spec,the case head to shoulder datum length has been reduced.

That's the desired result,Mr Guffey.All the rest of the reloaders(except you) call that bumping or setting the shoulder back.

Apparently you are the "Only Reloader" who cannot perform the shoulder adjustment that the rest of the reloaders have been doing since FL sizing dies have been produced

well said HiBC

 

[Unclenick]

Don't forget to trim after using the FL die. That's when cases grow.

You may want to experiment with turning the die back out so that your shoulder gets extruded down only about -0.001" to -0.002" shorter than your chamber headspace. That is what Mr. Guffey is doing with that 0.003" feeler gauge. That will reduce how much it stretches at the pressure ring during your first firing after a trip through the FL sizing die. In turn, that will increase the number of times you can fire it before pressure ring thinning becomes an issue. If you also anneal them just before you use the FL die and you are not using heavy loads, you may discover you can get 50 reloads out of the cases.


HiBC,

The RCBS Precision Mic is designed to determine chamber headspace by transfer measurement. It is premised on the idea the case will expand to fill the chamber on firing and therefore come out fireformed to mirror the chamber's size. When you put the fireformed case in the PM, it then reads the chamber's headspace by measuring the case (aka, taking the chamber measurement off the case). From RCBS's web site:

{The RCBS Precision Mic:}
• Determines chamber headspace and bullet seating depth to 0.001-inch
• Measures from the datum point on the caseshoulder to the base, giving reloaders spot-on SAAMI tolerance readings

In other words, it measures chamber headspace by taking it off the case or it measures whether the case head-to-shoulder length meets SAAMI spec or not, but nowhere does it claim to measure "case headspace". There is none as no case head has to go inside the case, and accommodating a case head is what headspace is for.

I promised I would put up a sticky for headspace so all such disputes could go there. I have the drawings ready and soon will put it up.

 

[HiBC]

Unclenick, I know the term "Cartridge Headspace" is technically incorrect.
I understand from chambering rifles that only the firearm has "headspace"

As folks try to learn about the reloading issues...over and over and over again,we have to use words to describe concepts.
"For lack of a better term"

Usually we are talking about how the reloader deals with the case head to shoulder datum length as it relates to his or her individual or multiple rifle chambers both before and after firing and how die settings may be used to correct or optimize the brass to chamber relationship.

I don't want to type all that every time.

At least one of the bushing gauge manufacturers calls the gauge a "Cartridge Headspace Gauge"

If I say " M-1 Carbine 30 round banana clip" everyone will cringe,I'll get criticized,but you will be able to see and understand what I'm taking about.

I have an easy,readily available,understandable term to use instead.,"30 round carbine magazine"

I use it. I don't use "Clip" except for en blocs and strippers.

Please,Unclenick,

I'm tired of this. I'd be grateful if you can offer a simple,three word term that we can use instead of "Cartridge Head Space" Even four or five words.

For "my bolt won't close" or "I'm getting head separations" etc.

And,FWIW,I have no doubt you are accurate and correct about RCBS and using the PM to measure chamber length.
I learned of the PM from Precision Shooting Magazine's book "Guide for reloading competition ammunition" or something like that.
They suggested using the PM to make a before and after sizing measurement of the cartridge case so we can optimize setback for brass life and rifle type...for example an M-1 might work better with .006 and a 1903 .002.

That is where I learned about the RCBS PM. I found the bushing gauge and ,if needed,the granite comparator stand with indicator to compliment the bushing gauge both cheaper and more efficient.

The various caliper and bushing setups work fine.

If I say "That's how I check cartridge headspace",you may cringe,you may roll your eyes,you may criticize and correct me,but we communicated and you know what I'm talking about.

For lack of a better term.

This link will get you to Sinclair (Brownells) Reasonably tech folks

https://www.sinclairintl.com/reload...g-tools/case-gauges-headspace-tools/index.htm

The Hornady bushing set and the RCBS PM are listed as "Cartridge length headspace" tools.There is a Wilson bushing shown, Click on it The description is "Cartridge length headspace gauge"

I agree,headspace is about the breech and chamber.That is the PARENT. but the cartridge case becomes a CHILD of that chamber,.Critical aspects of reloading and resizing are all about the parent headspace of that chamber.
Upon firing,those headspace measurements transfer to the brass.
We size to restore the brass dimensions to fit the rifle headspace.

IMO,we just make life difficult if the word "headspace" is taboo from cartridges unless there is another acceptable term.

 

[cw308]

RedSkyFarm
If your fired cases can't chamber , you can use the full length die and slowly lower each time with checking in your chamber until it chambers without resistance that would be your zero headspace measurement , it's best to do with a stripped bolt using only the housing for a better feel . Good Luck , glad everything worked out . Be Well .
PS
For hunting you may be better with .003 from bolt face to datum . I use my rifle for benchrest shooting only , only in good weather conditions so I keep my measurement from .001 to .002 no more or !ess . Hard bolt lifts will eventually wear on your bolt locking lugs and you don't want that .

Chris

 

[Unclenick]

I'd be grateful if you can offer a simple, three word term that we can use instead of "Cartridge Head Space" Even four or five words.

I appreciate that the correct terminology doesn't trip lightly off the tongue. I actually asked for suggestions for a new term in a past thread, but don't recall the outcome. Unfortunately, that means it wasn't memorable enough to take.

One of the members commented that he avoids having to find a term by discussing only Excess Headspace. That is extra room a chamber's headspace has for a cartridge. When the case head-to-headspace-datum measurement matches the headspace the excess headspace is zero. If it's too big, excess headspace gets a negative number, and if it is shorter than the chamber headspace then excess headspace gets a positive number.

Let's put out the call again for a better term that uses no more than three words. I've yet to find anything satisfactory on my own.

 

[cw308]

I still like headspace . Everyone knows what I mean . Just like tomato , potatoe , aunt and my favorite ask . I guess , to each his own and pray for the best . Making a mountain out of a mole hill . No Big Deal .Be Well Guys .

Chris
PS How about wiggle room . Sounds Precise .

 

[HiBC]

One of the members commented that he avoids having to find a term by discussing only Excess Headspace. That is extra room a chamber's headspace has for a cartridge. When the case head-to-headspace-datum measurement matches the headspace the excess headspace is zero. If it's too big, excess headspace gets a negative number, and if it is shorter than the chamber headspace then excess headspace gets a positive number.

OK. I chamber a rifle with headspace gauges. It just accepts the "GO" It won't accept the "No Go".

Nothing else is headspace and the headspace is perfect.

Cartridge case head to datum measurement is wrong.Ammo is wrong. Nothing needs to be done to the rifle.

How do we talk about it without using the word "Headspace" and correctly attribute it to the ammunition and discuss reloading techniques.

I value plain speaking over the contortions of political correctness.

Unclenick,I value and appreciate your answer. Thank you for recognizing my point.

In the mean time,until there is a consensus term that does not require a 3 paragraph explanation,I'm going to use "cartridge headspace" in quotes.

The quotes are a sign I do not need the argument "Cartridges don't have headspace"

If you ask me about cartridge length,I assume LOA I can give a number.

If you ask me about case length,I assume trim length.I can give a number.

If you ask me about cartridge headspace,I know what you mean,but I can't readily give you a meaningful number.What I measure is a comparative number."Fired brass was 2.XXX,and after sizing its 2.XXX (-.003). The .003 is the number I want and can measure. Head clearance.


My bushing gauge may tell me brass is ,004 over max SAAMI. That's a useful number.I suppose we could call it "Head interference"It can tell me its within SAAMI,High limit SAAMI,or .003 shorter than High SAAMI. I can establish that my 1903 has .002 Head clearance when its .003 shorter than bushing Gauge High SAAMI limit


Then there is the Basic Dimension,Maximum Material Condition,Minimum Material Condition,etc.If you don't have to allow for positional tolerance,

One approach ,two parts at basic dimension will be a line to line fit at Maximum material condition. But we are looking for simple,common language.

What I can talk about and measure,what is meaningful,and the point,is "Head Clearance" which is even technically accurate.

But to explain head clearance,I have to reference the "Cartridge Headspace" concept.

 

[cw308]

At one time I had no idea what runout was , even with runout and where you measure from makes a difference but even though you know what I'm talking about . When working in thousandths you have to be pretty technical . That's coming from a guy , if it wasn't for sports I would still be in high school. I still like " headspace " sorry .

 

[USSR]

Since the condition of excessive headspace and insufficient headspace in a rifle can be induced by the amount a shoulder is or is not bumped back, case headspace is a fitting term and one for which I will gladly suffer the slings and arrows of terminology purists on this site. Sorry.

Don

 

[Unclenick]

The reason for avoiding it is to prevent confusing newbies who may not at all know what you are talking about. I don't want to be asked, "how do I use this GO headspace gauge I bought to measure my cases?"

Anyway, I don't have a good terminology alternative to a full description. I thought of 'shoulder length' and 'datum length', but those only apply to cases that stop on their shoulders in the context of fitting into an allotted headspace. 'Case Headspace Fit' would seem to take the onus off the reader to realize headspace is not a characteristic of the case.

But maybe this is overthinking. Why not just say you are setting excess headspace instead of setting case headspace? The terms are all correct and excess headspace is, indeed, controlled by the sizing of rimless bottleneck cases and by trimming cases that stop on their mouths. There is no way to set it in a rimmed or a belted case, though you can sure set the head-to-shoulder datum length on either one and even change the surface that sets the headspace to the shoulder from the rim or belt.

Anyway, I'll ask you both to jot down any ideas that come to mind and post them in the headspace sticky I am creating.

 

[hounddawg]

I don't want to be asked, "how do I use this GO headspace gauge I bought to measure my cases?"

if the person asking has used that gage to set the headspace on a rifle using a barrel nut tell them to use a case comparitor like this

https://www.amazon.com/Hornady-HK66...nady+case+comparator&refinements=p_89:Hornady

and when setting up their resizing die to where the cases coming off the press match the reading they get using the comparitor against the GO gage. When they are equal the FL die is set correctly. DO NOT try this on a factory barreled rifle or a used rifle unless you have tried chambering both the GO and a NO Go gage to make sure the rifle was set up correctly

I have a pair of .260's I set up exactly the same way so I don't have to worry about sorting cases. As a test I chambered a case fired from each into the other and had no signs of bolt closing pressure with either rifle

 

[Metal god]

I appreciate that the correct terminology doesn't trip lightly off the tongue. I actually asked for suggestions for a new term in a past thread, but don't recall the outcome. Unfortunately, that means it wasn't memorable enough to take.

It was head clearance or casehead clearance , I liked head clearance but Slamfire preferred casehead clearance . But asking for everyone to make up a new term different then the one we ALLLL have excepted except one person and now you UN is NOT reasonable . Just like I have to except the word hack can be used in a way to mean something good . I don't like it , it was never used in that way for 45+ years of my life . Then the internet came along and people came up with new terms and the group excepted them . Hack ( doing something in a quick manner in a beneficial way ) and case headspace ( the distance from the case head to the datum point on a bottle neck case ) is but a few new terms the world has excepted as reasonable . The ignorance it takes to think he is the only one on the planet that gets to decide how others talk to one another or what words they use , is absurd .

Just because he wants to be old a stubborn doesn't mean the world is going to stop evolving .

The reason for avoiding it is to prevent confusing newbies who may not at all know what you are talking about.

There is only one person , well I guess two now that are confusing the new guys . That's the guys fighting every single time the term case headspace is used . Maybe if you two excepted what the industry and 99% of the reloaders have excepted as a new term . We could all move on .

If you'd like I'm more then willing to find every post a certain member has posted on this subject not only here but 5 other forums and the hundreds if not thousands of responses explaining in great detail how they disagree with him and he has been the only one defending his position on the subject .

Or Unclenick are you formally asking us all here at TFL to stop using the term case headspace and bump the shoulder back . Because if your not then you need to ask Mr Guffey to stop derailing threads every time those terms come up .

We've been going trough this for the 6 years I've been here EVERY time this topic comes up . I'd like you to either ask us all to stop using the terms that Hornady , RCBS and Berger have all excepted as reasonable to use or to ask Mr Guffey to stop arguing about those excepted terms with the members here .

Respectfully
Metal God

 

[hounddawg]

Great minds discuss ideas; average minds discuss events; small minds discuss people. Idiots argue semantics - apologies to Elanor Roosevelt

Might just be me but I am tired of the trolling on this forum on this forum. There are a lot of good people here trying to help the community and one or two who just want to pump up their tired ass egos and troll. If I go to the range and discuss cartridge headspace any reloader there knows what I am saying, I could give a s*** about the semantics as long as the communication takes place

just my 2 cents worth

 

[F. Guffey]

Reloaders were claiming they were bumping the shoulder back with a bump die; if there was such a die I am sure I had one but I had no clue what it looked like. So? That left me with asking questions. As everyone should expect that ran them out of gas and they got hostile.

I did a little search and found the manufacturer of the die the reloaders were calling a 'bump die'; I called them about their bump die and I wanted to know how to bump the shoulder back? with a die that did not have case body support. BECAUSE! reloaders on the internet were claiming they were bumping the shoulder back ONLY.

They responded: They said I knew and they knew it was impossible, the die reloaders were claiming to be a bump die was a bushing die and manufacturer made it very clear the bushing die was a sizing die that sized the shoulder and case body.

And then I reflected; I went to my library to retrieve the book on vanity; life is vanity all vanity. I thumbed through the book to a worn pace and there it was:

"It is greater to receive the wrath of a wise man than the rhetoric of a fool"

F. Guffey

 

[F. Guffey]

I could not understand why reloaders got all giggly bout bushing die. I have neve had to purchase one because I already had them. And then there was the problem with 'the donut'. I have chambers/cases that will never form a donut, I have chambers that are by design to create donuts and there are donuts that form because of bad habits.

F. Guffey