Winchester Brass

TGR · May 8, 2021

I’m working up a load for a new Christiansen Mesa in 308 Win. I’m using Win Brass, Ramshot TAC, and Hammer Hunters and Hornady SSTs. Varget and 748 are unobtanium.

The Brass was once fired by me, then I trimmed all to book trim-to length for uniformity. With barrel break-in and two load ladders, each piece of Brass was fired twice. I just measured the Brass and all but 4 out of 100 were past max length and needed trimming again. I figured a few of the top Loads would need trimming but not all. Each was full-length resized, the Christiansen has a tight chamber and I don’t want to run into problems in the field. The ladders were stopped at the first sign of pressure and the loads are all within normal parameters.

So my question is.....anything abnormal that I’m not seeing? I usually get 3-5 reloads before I need to trim in 308. Needing to trim after just 2 surprised me.

I know it’s not Lapua quality, but could it be the Winchester Brass?
.......

BTW, the Hammer Hunters are unbelievable. A little pricey, but hands down the most accurate bullet I’ve shot. Very consistent, Weights all with 0.1gr and very slick. I’m averaging 0.3 moa with the 152 Hammer Hunter.

E.Shell · May 8, 2021

Usually, excessive case stretch can be traced back to excessive full-length sizing.

TGR · May 8, 2021

I haven’t changed anything from what I normally do. I’ll try to fine tune to just a small shoulder bump I guess.

Pinecone · May 8, 2021

How much are you bumping the shoulder?

For a bolt gun 1 - 3 thou is the typical range. I shoot for closer to 1 thou

Speedluvn · May 9, 2021

E.Shell said:
Usually, excessive case stretch can be traced back to excessive full-length sizing.

I’ve been pondering this post. I just obtained a 308 rifle and have loaded my first 50 rounds for it. I have a Lee Turret and Lee single stage press. Can you explain your point of excessive full length sizing. I’m trying to understand how’s that possible.

dist1646 · May 9, 2021

Speedluvn said:
I’ve been pondering this post. I just obtained a 308 rifle and have loaded my first 50 rounds for it. I have a Lee Turret and Lee single stage press. Can you explain your point of excessive full length sizing. I’m trying to understand how’s that possible.

Basically, if you set your die so that it sizes the case to factory length but, your chamber is a little longer, the case will stretch to seal the chamber when fired, thus the case will become slightly thinner in the web section, eventually leading to separation. The chamber could be within safe specs. Seasoned reloaders will measure a case fired in that particular chamber and set their sizing die so that the case is approximately 0.002" shorter in order to insure reliable chambering and reduce the amount of case stretch. They make gauges that fit on a set of calibers for this purpose. If you look at the cartridge diagrams in a reloading manual, you will see what is referred to as the datum line and a measurement from that point to the base of the case. This is the measurement point needed to make the proper adjustment of the sizing die to fit your chamber. My 6XC die set from David Tubb came with the gauge for making this measurement. I believe Stoney Creek offers the necessary gauge for using a set of calibers to make the case measurement.

E.Shell · May 9, 2021

dist1646 said:
Basically, if you set your die so that it sizes the case to factory length but, your chamber is a little longer, the case will stretch to seal the chamber when fired, thus the case will become slightly thinner in the web section, eventually leading to separation. The chamber could be within safe specs. Seasoned reloaders will measure a case fired in that particular chamber and set their sizing die so that the case is approximately 0.002" shorter in order to insure reliable chambering and reduce the amount of case stretch. They make gauges that fit on a set of calibers for this purpose. If you look at the cartridge diagrams in a reloading manual, you will see what is referred to as the datum line and a measurement from that point to the base of the case. This is the measurement point needed to make the proper adjustment of the sizing die to fit your chamber. My 6XC die set from David Tubb came with the gauge for making this measurement. I believe Stoney Creek offers the necessary gauge for using a set of calibers to make the case measurement.

Good answer, posted while I was typing the below:

Speedluvn said:
...I’m trying to understand how’s that possible.

Short answer:
It is because we induce excessive *headspace* and stretch the cases when we set the shoulder back too far during sizing.

"Excessive" is defined as "more than necessary" and is not necessarily "dangerously excessive", although it can be.

Explanation:
When a cartridge case is fired, the case contains the pressure and expands in every direction to fill any voids between the chamber and cartridge case. The pressure within the case causes it to grip the chamber walls. As pressure subsides, the brass springs back a little and clears the chamber walls, allowing extraction.

We now have produced a case that is fire-formed to that chamber.

Now, we reload that case, and we need to reduce the neck to hold the new bullet and we need to create a very small amount of working clearance so that the reloaded case will freely enter the chamber, and we typically use a full-length sizing die to achieve this.

When we adjust our die, it is important to know that the die maker's goal is NOT the always same as YOUR goal, and the die maker's instructions are designed to achieve HIS goal, not YOURS/OURS.

OUR goal is to reuse these empty cases several times, while producing safe and accurate ammo that will fit our rifle.

The manufacturer's goal is to use that one case to produce ONE loaded cartridge that will function in any standard chamber firearm of that caliber. In doing do, the maker instructs the user to bring the full-length die down against the shellholder in the press. This die position produces the maximum amount of case size reduction, 'sizing', that the die will produce. They want no complaints about "won't chamber", even if your chamber is at SAAMI minimum, which most are NOT. So, if you set the die per instructions, you are crunching that piece of brass down as far as the die will do it and if your chamber is larger than minimum, even though less than SAAMI maximum, you create excessive clearance that the case gets blown out to fill during firing.

The sidewalls are pretty flexible and a little extra room here doesn't matter much. Where we get damaged here is that the shoulder position also gets moved back as far as the die will push it.

Now, we blindly follow the die maker's self-serving instructions and give it no further thought. We produce an SAAMI minimum cartridge that easily falls into the chamber of ANY rifle chamberered for that cartridge.

If we only wanted to shoot that empty case once more, we would be fine, but if we want to continue to reuse that case, we continue to cycle it between being expanded to fit YOUR chamber to being sized to fit ANY chamber.

We take our newly-loaded cartridge and chamber it. The clearance between the shoulder (that was pushed back further than necessary) and the chamber is at least a few thousandths, a little more if your chamber is larger than minimum.

When we fire the cartridge, the pressure from the firing pin spring pushes the cartridge into the chamber until it stops, then it begins to dent the primer cup and initiate ignition. The space that was formerly in front of the shoulder is gone, but is now between the case head and the bolt face.

This space is called *headspace*, because it is a gap/space between the case head and bolt face. It used to be shoulder-space, but that changed when the firing pin drove the case forward.

Excessive headspace can be dangerous, but most often it is just a little destructive, and here is how:

As primer ignites the powder and pressure begins to build, the case walls are pressed against the chamber walls. Obviously, the thinnest parts of the case yield most easily and thus expand first, which would be the case neck.

The case neck expands first under pressure and grips the chamber neck. The case shoulder would expand next, but it is already in tight contact with the chamber shoulder and has no place to go.

The case wall is tapered all the way down to the web, and the expansion to grip the chamber walls moves down the tapered walls as pressure builds. Finally, the pressure has expanded the relatively thin case wall to fit the chamber and a very tight grip is formed.

But what about the *headspace* that STILL exists, that gap we created when we set the shoulder back and it then got driven forward?

That space also gets closed by expanding brass. The case walls are tightly gripping the chamber and finally the very thickest part get stretched out and forced to fill the void and the case head is driven back against the bolt.

If the entire case is locked into the chamber by rapidly increasing pressure, and THEN we push the case head back, we have stretched that very narrow area that was too thick to expand immediately. When we move the case head back and stretch the brass during firing, that material has to come from *somewhere*.

The material comes from the case wall in that very narrow area just above the web. Anytime you stretch something, it gets thinner, right?

So, at this point, we have a stretched case with thinning walls. When we run that case back into the sizing die, we cannot restore that thin, stretched area and the entire case has 'grown' forward. We simply move the shoulder back with the die and this makes the neck longer, which manifests itself as a case that suddenly need trimming.

So, you trim your case and life seems good. But then you notice a case needs trimming very often and we inadvertently work to destroy it.

One or two firings are safe enough, but after several firings, we are flirting with case failure in the form of case head separation, all the while creating extra work for ourselves because we are setting our die to provide the results the manufacturer wants.

Many people jump to the conclusion that neck-sizing solves this problem, and it does, but at the expense of creating other problems inherent to not fully sizing the case. Precision can suffer, as a too-tightly fitting case pushes the bullet out of alignment with the throat. Reliability can suffer, as a neck-sized case does not always freely enter them chamber. Safety can be compromised in self-loaders, as the neck sized case resists freely chamber and create a potential for slam fires or out-of-battery ignition.

The REAL answer is to recognize the die maker's goals differ from yours and simply adjust the die to fit YOUR rifle and not some generic-one-size-fits-all dies setting intended to satisfy the masses and prevent customer complaints.

As posted above, very little clearance is needed at the shoulder and the best practice is to bump the shoulder back ONLY far enough to provide working clearances.

In my own rifles, I set my die to move the shoulder back 0.002" and it is very unusual to have to trim more than once every 4-5 firings.

Additional info here:
http://www.shell-central.com/Brass_Prep1.html

Seagrave1963 · May 9, 2021

E.Shell said:
Good answer, posted while I was typing the below:
Short answer:
It is because we induce excessive *headspace* and stretch the cases when we set the shoulder back too far during sizing.

"Excessive" is defined as "more than necessary" and is not necessarily "dangerously excessive", although it can be.

Explanation:
When a cartridge case is fired, the case contains the pressure and expands in every direction to fill any voids between the chamber and cartridge case. The pressure within the case causes it to grip the chamber walls. As pressure subsides, the brass springs back a little and clears the chamber walls, allowing extraction.

We now have produced a case that is fire-formed to that chamber.

Now, we reload that case, and we need to reduce the neck to hold the new bullet and we need to create a very small amount of working clearance so that the reloaded case will freely enter the chamber, and we typically use a full-length sizing die to achieve this.

When we adjust our die, it is important to know that the die maker's goal is NOT the always same as YOUR goal, and the die maker's instructions are designed to achieve HIS goal, not YOURS/OURS.

OUR goal is to reuse these empty cases several times, while producing safe and accurate ammo that will fit our rifle.

The manufacturer's goal is to use that one case to produce ONE loaded cartridge that will function in any standard chamber firearm of that caliber. In doing do, the maker instructs the user to bring the full-length die down against the shellholder in the press. This die position produces the maximum amount of case size reduction, 'sizing', that the die will produce. They want no complaints about "won't chamber", even if your chamber is at SAAMI minimum, which most are NOT. So, if you set the die per instructions, you are crunching that piece of brass down as far as the die will do it and if your chamber is larger than minimum, even though less than SAAMI maximum, you create excessive clearance that the case gets blown out to fill during firing.

The sidewalls are pretty flexible and a little extra room here doesn't matter much. Where we get damaged here is that the shoulder position also gets moved back as far as the die will push it.

Now, we blindly follow the die maker's self-serving instructions and give it no further thought. We produce an SAAMI minimum cartridge that easily falls into the chamber of ANY rifle chamberered for that cartridge.

If we only wanted to shoot that empty case once more, we would be fine, but if we want to continue to reuse that case, we continue to cycle it between being expanded to fit YOUR chamber to being sized to fit ANY chamber.

We take our newly-loaded cartridge and chamber it. The clearance between the shoulder (that was pushed back further than necessary) and the chamber is at least a few thousandths, a little more if your chamber is larger than minimum.

When we fire the cartridge, the pressure from the firing pin spring pushes the cartridge into the chamber until it stops, then it begins to dent the primer cup and initiate ignition. The space that was formerly in front of the shoulder is gone, but is now between the case head and the bolt face.

This space is called *headspace*, because it is a gap/space between the case head and bolt face. It used to be shoulder-space, but that changed when the firing pin drove the case forward.

Excessive headspace can be dangerous, but most often it is just a little destructive, and here is how:

As primer ignites the powder and pressure begins to build, the case walls are pressed against the chamber walls. Obviously, the thinnest parts of the case yield most easily and thus expand first, which would be the case neck.

The case neck expands first under pressure and grips the chamber neck. The case shoulder would expand next, but it is already in tight contact with the chamber shoulder and has no place to go.

The case wall is tapered all the way down to the web, and the expansion to grip the chamber walls moves down the tapered walls as pressure builds. Finally, the pressure has expanded the relatively thin case wall to fit the chamber and a very tight grip is formed.

But what about the *headspace* that STILL exists, that gap we created when we set the shoulder back and it then got driven forward?

That space also gets closed by expanding brass. The case walls are tightly gripping the chamber and finally the very thickest part get stretched out and forced to fill the void and the case head is driven back against the bolt.

If the entire case is locked into the chamber by rapidly increasing pressure, and THEN we push the case head back, we have stretched that very narrow area that was too thick to expand immediately. When we move the case head back and stretch the brass during firing, that material has to come from *somewhere*.

The material comes from the case wall in that very narrow area just above the web. Anytime you stretch something, it gets thinner, right?

So, at this point, we have a stretched case with thinning walls. When we run that case back into the sizing die, we cannot restore that thin, stretched area and the entire case has 'grown' forward. We simply move the shoulder back with the die and this makes the neck longer, which manifests itself as a case that suddenly need trimming.

So, you trim your case and life seems good. But then you notice a case needs trimming very often and we inadvertently work to destroy it.

One or two firings are safe enough, but after several firings, we are flirting with case failure in the form of case head separation, all the while creating extra work for ourselves because we are setting our die to provide the results the manufacturer wants.

Many people jump to the conclusion that neck-sizing solves this problem, and it does, but at the expense of creating other problems inherent to not fully sizing the case. Precision can suffer, as a too-tightly fitting case pushes the bullet out of alignment with the throat. Reliability can suffer, as a neck-sized case does not always freely enter them chamber. Safety can be compromised in self-loaders, as the neck sized case resists freely chamber and create a potential for slam fires or out-of-battery ignition.

The REAL answer is to recognize the die maker's goals differ from yours and simply adjust the die to fit YOUR rifle and not some generic-one-size-fits-all dies setting intended to satisfy the masses and prevent customer complaints.

As posted above, very little clearance is needed at the shoulder and the best practice is to bump the shoulder back ONLY far enough to provide working clearances.

In my own rifles, I set my die to move the shoulder back 0.002" and it is very unusual to have to trim more than once every 4-5 firings.

Additional info here:
http://www.shell-central.com/Brass_Prep1.html

More amazing guidance on MDS - Thank you Ed!

Doco Overboard · May 9, 2021

There it is, as it has been written above.
The other thing that happens is that even in the same lot of "cups" formed during the brass manufacture , the metallurgy involved in the brass composition differs very slightly regardless of the most advanced selection and and component lot consistency during the initial forming process.
Also, when manufacturing occurs- slight tool and machinery changes have a bearing on the same, as cases are actually being drawn and formed for how much they stretch once fired.

Harrys · May 9, 2021

Just to add bottleneck cases are notorious by design in stretching big hole going through little hole. Measuring your head space to ensure rather than guessing. http://www.floridareloading.com/index.php/2017/02/04/proper-full-length-sizing-for-bottleneck-cases/

Straight cases are less likely to stretch very seldom do I have to trim them when fired.

E.Shell · May 9, 2021

Harrys said:
...Straight cases are less likely to stretch very seldom do I have to trim them when fired.

The whole shoulder setback thing is missing...

Speedluvn · May 10, 2021

dist1646 said:
Basically, if you set your die so that it sizes the case to factory length but, your chamber is a little longer, the case will stretch to seal the chamber when fired, thus the case will become slightly thinner in the web section, eventually leading to separation. The chamber could be within safe specs. Seasoned reloaders will measure a case fired in that particular chamber and set their sizing die so that the case is approximately 0.002" shorter in order to insure reliable chambering and reduce the amount of case stretch. They make gauges that fit on a set of calibers for this purpose. If you look at the cartridge diagrams in a reloading manual, you will see what is referred to as the datum line and a measurement from that point to the base of the case. This is the measurement point needed to make the proper adjustment of the sizing die to fit your chamber. My 6XC die set from David Tubb came with the gauge for making this measurement. I believe Stoney Creek offers the necessary gauge for using a set of calibers to make the case measurement.

E.Shell said:
Good answer, posted while I was typing the below:
Short answer:
It is because we induce excessive *headspace* and stretch the cases when we set the shoulder back too far during sizing.

"Excessive" is defined as "more than necessary" and is not necessarily "dangerously excessive", although it can be.

Explanation:
When a cartridge case is fired, the case contains the pressure and expands in every direction to fill any voids between the chamber and cartridge case. The pressure within the case causes it to grip the chamber walls. As pressure subsides, the brass springs back a little and clears the chamber walls, allowing extraction.

We now have produced a case that is fire-formed to that chamber.

Now, we reload that case, and we need to reduce the neck to hold the new bullet and we need to create a very small amount of working clearance so that the reloaded case will freely enter the chamber, and we typically use a full-length sizing die to achieve this.

When we adjust our die, it is important to know that the die maker's goal is NOT the always same as YOUR goal, and the die maker's instructions are designed to achieve HIS goal, not YOURS/OURS.

OUR goal is to reuse these empty cases several times, while producing safe and accurate ammo that will fit our rifle.

The manufacturer's goal is to use that one case to produce ONE loaded cartridge that will function in any standard chamber firearm of that caliber. In doing do, the maker instructs the user to bring the full-length die down against the shellholder in the press. This die position produces the maximum amount of case size reduction, 'sizing', that the die will produce. They want no complaints about "won't chamber", even if your chamber is at SAAMI minimum, which most are NOT. So, if you set the die per instructions, you are crunching that piece of brass down as far as the die will do it and if your chamber is larger than minimum, even though less than SAAMI maximum, you create excessive clearance that the case gets blown out to fill during firing.

The sidewalls are pretty flexible and a little extra room here doesn't matter much. Where we get damaged here is that the shoulder position also gets moved back as far as the die will push it.

Now, we blindly follow the die maker's self-serving instructions and give it no further thought. We produce an SAAMI minimum cartridge that easily falls into the chamber of ANY rifle chamberered for that cartridge.

If we only wanted to shoot that empty case once more, we would be fine, but if we want to continue to reuse that case, we continue to cycle it between being expanded to fit YOUR chamber to being sized to fit ANY chamber.

We take our newly-loaded cartridge and chamber it. The clearance between the shoulder (that was pushed back further than necessary) and the chamber is at least a few thousandths, a little more if your chamber is larger than minimum.

When we fire the cartridge, the pressure from the firing pin spring pushes the cartridge into the chamber until it stops, then it begins to dent the primer cup and initiate ignition. The space that was formerly in front of the shoulder is gone, but is now between the case head and the bolt face.

This space is called *headspace*, because it is a gap/space between the case head and bolt face. It used to be shoulder-space, but that changed when the firing pin drove the case forward.

Excessive headspace can be dangerous, but most often it is just a little destructive, and here is how:

As primer ignites the powder and pressure begins to build, the case walls are pressed against the chamber walls. Obviously, the thinnest parts of the case yield most easily and thus expand first, which would be the case neck.

The case neck expands first under pressure and grips the chamber neck. The case shoulder would expand next, but it is already in tight contact with the chamber shoulder and has no place to go.

The case wall is tapered all the way down to the web, and the expansion to grip the chamber walls moves down the tapered walls as pressure builds. Finally, the pressure has expanded the relatively thin case wall to fit the chamber and a very tight grip is formed.

But what about the *headspace* that STILL exists, that gap we created when we set the shoulder back and it then got driven forward?

That space also gets closed by expanding brass. The case walls are tightly gripping the chamber and finally the very thickest part get stretched out and forced to fill the void and the case head is driven back against the bolt.

If the entire case is locked into the chamber by rapidly increasing pressure, and THEN we push the case head back, we have stretched that very narrow area that was too thick to expand immediately. When we move the case head back and stretch the brass during firing, that material has to come from *somewhere*.

The material comes from the case wall in that very narrow area just above the web. Anytime you stretch something, it gets thinner, right?

So, at this point, we have a stretched case with thinning walls. When we run that case back into the sizing die, we cannot restore that thin, stretched area and the entire case has 'grown' forward. We simply move the shoulder back with the die and this makes the neck longer, which manifests itself as a case that suddenly need trimming.

So, you trim your case and life seems good. But then you notice a case needs trimming very often and we inadvertently work to destroy it.

One or two firings are safe enough, but after several firings, we are flirting with case failure in the form of case head separation, all the while creating extra work for ourselves because we are setting our die to provide the results the manufacturer wants.

Many people jump to the conclusion that neck-sizing solves this problem, and it does, but at the expense of creating other problems inherent to not fully sizing the case. Precision can suffer, as a too-tightly fitting case pushes the bullet out of alignment with the throat. Reliability can suffer, as a neck-sized case does not always freely enter them chamber. Safety can be compromised in self-loaders, as the neck sized case resists freely chamber and create a potential for slam fires or out-of-battery ignition.

The REAL answer is to recognize the die maker's goals differ from yours and simply adjust the die to fit YOUR rifle and not some generic-one-size-fits-all dies setting intended to satisfy the masses and prevent customer complaints.

As posted above, very little clearance is needed at the shoulder and the best practice is to bump the shoulder back ONLY far enough to provide working clearances.

In my own rifles, I set my die to move the shoulder back 0.002" and it is very unusual to have to trim more than once every 4-5 firings.

Additional info here:
http://www.shell-central.com/Brass_Prep1.html

Thank you both for your responses. I will be rereading these post repeatedly to begin to understand this new-to-me process.

dannyp · May 10, 2021

that is truly a great write up of why it needs to be done a certain way .

Pinecone · May 10, 2021

Harrys said:
Straight cases are less likely to stretch very seldom do I have to trim them when fired.

You must not shoot .30 Carbine.

TGR · May 10, 2021

Excellent inputs! What is confusing to me is that I believe this chamber is much tighter than the other 308s I have. I could understand the change if it was a looser chamber but not tighter. Either way, when I get back in town I will measure the shoulder bump and adjust accordingly.

E.Shell · May 10, 2021

TGR said:
Excellent inputs! What is confusing to me is that I believe this chamber is much tighter than the other 308s I have. I could understand the change if it was a looser chamber but not tighter. Either way, when I get back in town I will measure the shoulder bump and adjust accordingly.

"Tight chamber" can mean short throat, and/or small diameter neck, and/or SAAMI minimum (just headspace or all over), or...it could just be a figure of speech, which it often is.

Tight necks or short throats have nothing to do with the headspace potentials. I've run quite a few precision rifles that headspaced normally. Absolute headspace is one of the least factors in rifle chambering precision and is why even benchrest dies are adjustable.

Even **IF** your chamber actually IS at SAAMI minimum, a standard die set is still designed to reduce the cartridge case to provide ample clearance, which could be too much for your chamber.

Every thousandth of an inch in headspace with a loaded cartridge in your chamber, excess or not, equates to a thousandth of an inch in case stretch per firing. The difference between 'max length' and 'trim to' is usually about 0.010". If you are setting your shoulder back 0.005", you get two shots between trims if your brass isn't particularly soft as mentioned by Doco Overboard above. I have known Federal Gold Medal Match and Norma brass to be soft, but WW has always been OK for me.

My suggestion would be to set up your die using a proper gauge or using the directions I have at the link in my post above. Find 0.002" clearance, which is enough that you won't feel any resistance to closing the bolt and a tiny bit of debris or unburnt powder won't prevent chambering, but still close enough to slow down your stretching procedure.

Your actual headspace using your handloads in your rifle can be determined right now without fancy tools and without firing a shot: You can cut some small discs of shim stock of varying thicknesses, then use a film of grease to hold it to the case head of your loaded cartridge, and measure your actual headspace by adding shims until the bolt won't close under normal pressure. In a pinch, you can use layers of firm tape, like acrylic tape, but you have to use a very light touch - metal shim stock is best.

ETA: Be careful, do NOT fire your rifle indoors.

TGR · May 11, 2021

E.Shell said:
Every thousandth of an inch in headspace with a loaded cartridge in your chamber, excess or not, equates to a thousandth of an inch in case stretch per firing. The difference between 'max length' and 'trim to' is usually about 0.010". If you are setting your shoulder back 0.005", you get two shots between trims if your brass isn't particularly soft as mentioned by Doco Overboard above. I have known Federal Gold Medal Match and Norma brass to be soft, but WW has always been OK for me.

My suggestion would be to set up your die using a proper gauge or using the directions I have at the link in my post above. Find 0.002" clearance, which is enough that you won't feel any resistance to closing the bolt and a tiny bit of debris or unburnt powder won't prevent chambering, but still close enough to slow down your stretching procedure.

ETA: Be careful, do NOT fire your rifle indoors.

The first paragraph explains it perfectly to me.

I have the tools, will update you all when I get back from this this trip and measure it. The reason I say this chamber is tight is because fired brass from my other 308s (Winchesters) will not chamber in this rifle. I can’t even get the bolt to start camming over. But what you say makes perfect sense regarding all the other variables besides the shoulder that could contribute to that.

Always learning something new with this hobby! Thanks

Harrys · May 11, 2021

Pinecone said:
You must not shoot .30 Carbine.

Nope, 45/70 and 50 cal. S&W magnum very seldom have I had to trim the cases after firing in my rifle and pistol. I make dummy rounds for each type of bullet head I use. Regardless of projectile my cases are the same COL chambered to the gnats ass specifically for my rifle and pistol. If I buy new or once fired brass I need to trim them.

byf43 · May 11, 2021

Harrys said:
Nope, 45/70 and 50 cal. S&W magnum very seldom have I had to trim the cases after firing in my rifle and pistol. I make dummy rounds for each type of bullet head I use. Regardless of projectile my cases are the same COL chambered to the gnats ass specifically for my rifle and pistol. If I buy new or once fired brass I need to trim them.

I don't load .45-70 Gov't 'hot', and I trim my cases every 4th or 5th firing.
In fact, I shoot a rather 'mild' load, running right at 1600+/- fps. using RL-7.

.44 Magnum loads and .357 Magnum get trimmed, also, especially when I was shooting IHMSA w/ the DW .44.

A consistent length and crimp leads to better accuracy, IMNSHO.

Now, my .357 loads are basically bunny fart loads, and I don't even use a crimp on them, so, I haven't trimmed any of these cases in years. At least 10 years.

Doco Overboard · May 11, 2021

E.Shell said:
"Tight chamber" can mean short throat, and/or small diameter neck, and/or SAAMI minimum (just headspace or all over), or...it could just be a figure of speech, which it often is.

Tight necks or short throats have nothing to do with the headspace potentials. I've run quite a few precision rifles that headspaced normally. Absolute headspace is one of the least factors in rifle chambering precision and is why even benchrest dies are adjustable.

Even **IF** your chamber actually IS at SAAMI minimum, a standard die set is still designed to reduce the cartridge case to provide ample clearance, which could be too much for your chamber.

Every thousandth of an inch in headspace with a loaded cartridge in your chamber, excess or not, equates to a thousandth of an inch in case stretch per firing. The difference between 'max length' and 'trim to' is usually about 0.010". If you are setting your shoulder back 0.005", you get two shots between trims if your brass isn't particularly soft as mentioned by Doco Overboard above. I have known Federal Gold Medal Match and Norma brass to be soft, but WW has always been OK for me.

My suggestion would be to set up your die using a proper gauge or using the directions I have at the link in my post above. Find 0.002" clearance, which is enough that you won't feel any resistance to closing the bolt and a tiny bit of debris or unburnt powder won't prevent chambering, but still close enough to slow down your stretching procedure.

Your actual headspace using your handloads in your rifle can be determined right now without fancy tools and without firing a shot: You can cut some small discs of shim stock of varying thicknesses, then use a film of grease to hold it to the case head of your loaded cartridge, and measure your actual headspace by adding shims until the bolt won't close under normal pressure. In a pinch, you can use layers of firm tape, like acrylic tape, but you have to use a very light touch - metal shim stock is best.

ETA: Be careful, do NOT fire your rifle indoors.

To parrot what Ed says above who should have wrote a book already is, if you do not want to worry about achieving excess case stretch, or minimize as much as possible, have a die custom made/ground that replicates your chamber as closely as possible. And even then, brass is still going to stretch a certain amount due to elasticity margins built in to the brass such as releasing tension on the bullet to minimize pressure etc etc.
The pressure upon firing and gas control is expounding on the interior of the case wall to fill and expand very nook and cranny till it springs back enough to allow extraction. It's a little pressure vessel that needs to be sealed at the rear until the bullet is started into the bore where the emerging gas that hasn't already escaped follows the projie nearly through the bore and then some.
One other thing, there is also a certain amount of calories ie heat that is transmitted to the brass, the bullet and chamber walls+ a certain amount that is waisted escaping from the bore in the emergent gas and the gas behind the bullet that imparts energy. Heat equals the ability of the powder to be transformed into work so and so forth.
The best HS gauges I own are cartridge cases fired and matched to a particular rifle.
Period.
Lastly that fancy cartridge case gauge we all rave about, only lets you know if cartridge headspace is within acceptable range, it doesn't tell you doodly squat what your chamber HS is.
Your fired cartridge does. In case anyone was wondering.
Doco out.

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