So my uncle gave me a 338 win mag savage that he wants the barrel swapped out. So before hand I had a chance to practice and rechamber to a 338 rum. I reamed it out by hand and go gauge and no go gauge are correct even the go gauge with a piece of masking tape on the back. My question is this and bare with me I'm learning not doing this as a profession. I was told sometimes you could use a fired cartridge for a go gauge. However the cartridge fired and ejected but if you try to put the fired cartridge back in it gets stuck so I took the action back off and stuck it down into the chamber and it was very rough to pull out. If I stick a new round down in and turn it upside down it falls out. I was supervised under a gunsmith while doing this project so everything was preformed safe but I was told to figure out why or if it was normal. So some help here please.
Head spacing question
- Thread starter Fire8523
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You were told sometimes you could use a fired cartridge for a go gauge, I have heard that, and I have read that on the Internet. The answer is no.
You cut the chamber, you should know the length of the chamber from the shoulder to the bolt face before, during and after cutting the chamber.
Then there is the other part of your question, you should know what happened to the case when it was fired, not easy, it is about discipline. Measure the case before and again after firing. When measuring the case it is important to know the diameter of the case and chamber.
I have been involved in some very boring threads that involve ‘mysteries’, such as the second part of your question. ‘The case will not chamber after being fired’, according to the Internet? It should, because of jump back, snap back and or recovery as though the case has a memory of what it was before the trigger was pulled. That worked for everyone but me, I have cases that have no memory of what they were when they were manufactured. I have cases that would not fit the shell holder after being fired.
Then there are pressure type test, another very boring topic. Back to the case that will not chamber after firing: Spring back, jump back and case memory, when I have a case that will not chamber after firing I immediately consider the memory, recovery, snap back or jump back had nothing to do with the case but the chamber, when I have a case that will not chamber after firing I am conditioned to consider the chamber is being strained, that happens all the time, but not to the extent the case will not chamber. so, my suggestion is to consider backing off on the weight of the bullet and or amount of powder you are using.
You should consider reducing the load and start over when developing loads.
F. Guffey
You cut the chamber, you should know the length of the chamber from the shoulder to the bolt face before, during and after cutting the chamber.
Then there is the other part of your question, you should know what happened to the case when it was fired, not easy, it is about discipline. Measure the case before and again after firing. When measuring the case it is important to know the diameter of the case and chamber.
I have been involved in some very boring threads that involve ‘mysteries’, such as the second part of your question. ‘The case will not chamber after being fired’, according to the Internet? It should, because of jump back, snap back and or recovery as though the case has a memory of what it was before the trigger was pulled. That worked for everyone but me, I have cases that have no memory of what they were when they were manufactured. I have cases that would not fit the shell holder after being fired.
Then there are pressure type test, another very boring topic. Back to the case that will not chamber after firing: Spring back, jump back and case memory, when I have a case that will not chamber after firing I immediately consider the memory, recovery, snap back or jump back had nothing to do with the case but the chamber, when I have a case that will not chamber after firing I am conditioned to consider the chamber is being strained, that happens all the time, but not to the extent the case will not chamber. so, my suggestion is to consider backing off on the weight of the bullet and or amount of powder you are using.
You should consider reducing the load and start over when developing loads.
F. Guffey
I do not know what was said, I do not know what you thought you heard, it is possible for a skilled reloader to form cases with varying length from the shoulder back to the head of the case, the length of a case (30/06) can vary .028” from the shoulder/datum to the head of the case. For me that is –.012” shorter than a minimum length case (.017” shorter than a go gage length chamber) to .016” longer than a minimum length case (.011” longer than a field reject length chamber).
WHY? I do not have one rifle with a 30/06 chamber, I do not have one Mauser with an 8mm57 chamber, I am not the fan of starting over every day, so I make/form cases with varying length between the shoulder of the case to the head of the case.
Then there is something beyond purchasing bushings from Lowe’s and Home Depot, there are at least three different methods for checking the length of the chamber form the shoulder to the bolt face.
F. Guffey
WHY? I do not have one rifle with a 30/06 chamber, I do not have one Mauser with an 8mm57 chamber, I am not the fan of starting over every day, so I make/form cases with varying length between the shoulder of the case to the head of the case.
Then there is something beyond purchasing bushings from Lowe’s and Home Depot, there are at least three different methods for checking the length of the chamber form the shoulder to the bolt face.
F. Guffey
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A case, fired or unfired, can't be used as a gauge for the simple reason that the whole headspace business, gauges and all, is made necessary because cartridges are not uniform. If every cartridge were perfect, of the exact loading manual dimensions, every rifle could be made to accommodate those perfect cartridges and there would be no threads like this.
But cartridges vary (for many reasons), and real specs are in +/- dimensions. Rifles have to be made to accommodate that range of cartridge dimensions. The chamber must be long enough that the longest cartridge that is within spec will fit. And not so long that the shortest cartridge that is within spec will not separate when fired.
Now the .338 Win Mag is a belted case, so it headspaces on the belt, not on the shoulder, and it is that dimension the gauges measure. (In theory, the shoulder should also be correct but, as in a rimmed case, the shoulder is not that important to firing, though it certainly is to reloading.)
Contrary to what is often written, the belt does not strengthen the case; it is too far back. It is designed to act like a rim and provide a headspace point that is easier to feed from a magazine than a rim.
One problem with a belted magnum is that if headspace is a bit excessive, the belted case will actually be more prone to separation than a rimmed case. The reason is that the sharp angle at the belt is a stress riser and is at a thinner point of the case than the rim. So if the case is allowed to back up at all, the belted case will separate at the front of the belt. So headspace is very critical with a belted cartridge.
Jim
But cartridges vary (for many reasons), and real specs are in +/- dimensions. Rifles have to be made to accommodate that range of cartridge dimensions. The chamber must be long enough that the longest cartridge that is within spec will fit. And not so long that the shortest cartridge that is within spec will not separate when fired.
Now the .338 Win Mag is a belted case, so it headspaces on the belt, not on the shoulder, and it is that dimension the gauges measure. (In theory, the shoulder should also be correct but, as in a rimmed case, the shoulder is not that important to firing, though it certainly is to reloading.)
Contrary to what is often written, the belt does not strengthen the case; it is too far back. It is designed to act like a rim and provide a headspace point that is easier to feed from a magazine than a rim.
One problem with a belted magnum is that if headspace is a bit excessive, the belted case will actually be more prone to separation than a rimmed case. The reason is that the sharp angle at the belt is a stress riser and is at a thinner point of the case than the rim. So if the case is allowed to back up at all, the belted case will separate at the front of the belt. So headspace is very critical with a belted cartridge.
Jim
Jim K. good point, I am accused of typing in a confusion manner, never have I accused someone of not being able to read and or understand or comprehend what they read, strange thing, when I read the question he said he chambered the rifle to a Remington Ultra Magnum.
Not good, the diameter of the case head is the same for both.
F. Guffey
Not good, the diameter of the case head is the same for both.
F. Guffey
Ok so I examined the case there is no signs of over pressure cracking or any deformities it just seems to be very tight in the chamber as compared to a unfired round. It is a 338 rum round. I guess my question should be is this normal expansion or did something go wrong. A unfired round will fall right out if I turn the barrel upside down a fired round will not maybe to much stress?
W.E.G.
Member
An RCBS Precision Mic for your caliber is your friend.
Full-length resize the fired case until it chambers without resistance.
You will need to back-down the sizing die very-little by very-little until you achieve this.
At that point you can measure the re-sized case in your Precision Mic.
The nominal reading on the Precision Mic is the reference point you will want to use for your handloads.
This will be the dimension that is correct for THAT rifle, with THAT barrel.
If you don't have a micrometer-type tool to measure your ammunition, and your fired cases, you're doing it wrong.
Full-length resize the fired case until it chambers without resistance.
You will need to back-down the sizing die very-little by very-little until you achieve this.
At that point you can measure the re-sized case in your Precision Mic.
The nominal reading on the Precision Mic is the reference point you will want to use for your handloads.
This will be the dimension that is correct for THAT rifle, with THAT barrel.
If you don't have a micrometer-type tool to measure your ammunition, and your fired cases, you're doing it wrong.
Reloadron
Contributing Member
Going back to fguffey's initial post. Will a fired case drop out of the barrel? Sometimes they will and sometimes they won't. I like how fguffey worded this:
When a new properly sized case like new factory ammunition is fired it expands but is limited by the size of the chamber, assuming a good chamber. Following expansion it immediately contracts. How much? How much is debatable but many say about .001". In theory one would think a fired case would easily return to the chamber it was fired in but unfortunately things don't always work out that way. There is no set rule.This is especially true if you have a tight chamber. As chamber reamers wear they do get smaller.
Now if you have some calipers or a good micrometer you can take some case measurements on a fired case verse an unfired factory loaded case at some points and note some diameters. You can take some dykem or just use a magic marker and coat a fired case. Now try and chamber it. Look for the scratches where the case is rubbing. Measure and compare that area to the same area of the new unfired case.
W.E.G. mentions the RCBS precision mic sets. I use them but only on my more accurate rifles. They are a very good and useful tool but I confess I seldom use them for loading hunting rounds for a bolt gun.
Ron
243winxb
Member
Oval Chamber
Oval Chamber
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No. A fired case may be elongated thanks to the brass stretching. There are too many factors at play: how old that case is and how often its been reloaded, whether it's ever been trimmed and measured, the condition of the chamber that the case was fired in.
rcmodel
Member in memoriam
To cut to the chase on the OP's question.
No, you cannot use a fired case for a headspace gage.
Because you don't know if the headspace was Min, Max, or over-max in the chamber it was fired in the first time.
rc
No, you cannot use a fired case for a headspace gage.
Because you don't know if the headspace was Min, Max, or over-max in the chamber it was fired in the first time.
rc
My error in misreading. Fire8523 and F. Guffey are correct. The re-chambering is TO .338 Rem. Ultra Mag, which has a larger base than the .338 WM and a rebated rim. It does not have a belt and is supported (headspaced) on its shoulder.
A .338 WM chamber should clean up to .338 RUM but the COAL will be about 1/4" greater which may cause magazine problems.
But regardless, you cannot use a fired OR AN UNFIRED case as a gauge. The varying dimensions I mentioned apply to factory ammo as well as fired cases or reloads.
Jim
A .338 WM chamber should clean up to .338 RUM but the COAL will be about 1/4" greater which may cause magazine problems.
But regardless, you cannot use a fired OR AN UNFIRED case as a gauge. The varying dimensions I mentioned apply to factory ammo as well as fired cases or reloads.
Jim
Jim K, I am the one that types in a confusing manner, I am not the one with all the comparators they purchased believing they were purchasing head space gages.
In regard to what comes after ‘But regardless, you cannot use a fired OR AN UNFIRED case as a gauge’, I can measure the length of a chamber with a unfired case, nice to know? Helpful?
Reloaders, bench resters etc., use fired cases to determine the length of the chamber from the shoulder to the face of the bolt, THEN? they decide they can not do ‘it’ nor can anyone else do ‘it’ because of spring back, snap back, jump back or case memory and then someone decides a case is not fully grown because it has not been fired 5 times. I do not disagree with
them, if they are convinced they can not do it, they can not do it.
I was in a gun parts store when a customer ask to have the head space checked on a very expensive rifle with a very rare chamber, the smith/owner said he did not have a gage for his chamber, the owner of the very expensive rifle left, then I explained to the smith/owner I could check the length of any chamber from the shoulder/datum to the bolt face. Rather approach me in a manner rather rude, he ask ‘HOW!'? I explained/demonstrated one of the methods, he thought about it and ask why no one else has thought of checking the length of the chamber without head space gages, I then explained to him if he had confidence in his head space gages I could modify them to ‘go to infinity gages’.
Back to the boring story about the effect pressure has on the case and the chamber:
http://thefiringline.com/forums/showthread.php?t=341348
Firing the 338 RUM could be a workout for the Savage, it is possible the chamber is expanding but the case is not recovering, I suggested he reduce his loads and develop his loads for that rifle. I know he was was practicing, ‘with supervision’.
F. Guffey
In regard to what comes after ‘But regardless, you cannot use a fired OR AN UNFIRED case as a gauge’, I can measure the length of a chamber with a unfired case, nice to know? Helpful?
Reloaders, bench resters etc., use fired cases to determine the length of the chamber from the shoulder to the face of the bolt, THEN? they decide they can not do ‘it’ nor can anyone else do ‘it’ because of spring back, snap back, jump back or case memory and then someone decides a case is not fully grown because it has not been fired 5 times. I do not disagree with
them, if they are convinced they can not do it, they can not do it.
I was in a gun parts store when a customer ask to have the head space checked on a very expensive rifle with a very rare chamber, the smith/owner said he did not have a gage for his chamber, the owner of the very expensive rifle left, then I explained to the smith/owner I could check the length of any chamber from the shoulder/datum to the bolt face. Rather approach me in a manner rather rude, he ask ‘HOW!'? I explained/demonstrated one of the methods, he thought about it and ask why no one else has thought of checking the length of the chamber without head space gages, I then explained to him if he had confidence in his head space gages I could modify them to ‘go to infinity gages’.
Back to the boring story about the effect pressure has on the case and the chamber:
http://thefiringline.com/forums/showthread.php?t=341348
Firing the 338 RUM could be a workout for the Savage, it is possible the chamber is expanding but the case is not recovering, I suggested he reduce his loads and develop his loads for that rifle. I know he was was practicing, ‘with supervision’.
F. Guffey
Just for the record I had pacific gauge go and no go gauges. All the gauges Checked out fine the go closed and no go didn't I just thought maybe I did something wrong that a fired cartridge would get stuck and a un fired would fall right out with no resistance. These were factory loads nosler custom 225 grain trophies. I will check the case with a caliper and the factory load and see we're the expansion is. Thanks for all the advice
rcmodel
Member in memoriam
You didn't do anything wrong.
You can't expect a fired case to fit back in a different chamber.
That's why we have to resize them in a sizing die when we reload them.
rc
You can't expect a fired case to fit back in a different chamber.
That's why we have to resize them in a sizing die when we reload them.
rc
rcmodel, "You can't expect a fired case to fit back in a different chamber"
I am the one that is accused of not being able to type in a legible manner, I have never questioned the ability of the reader to comprehend, and as I have said I place no responsible on the reader to try and or make an effort.
It could be I am a better reader/comprehended so I will point out to you he is firing the cases and then discovering "However the cartridge fired and ejected but if you try to put the fired cartridge back 'the' cases will not chamber" in his first post, then he said it again just before you assured him he did nothing wrong.
Then you assumed he was using cases he found on the ground at a firing range.
F. Guffey
I am the one that is accused of not being able to type in a legible manner, I have never questioned the ability of the reader to comprehend, and as I have said I place no responsible on the reader to try and or make an effort.
It could be I am a better reader/comprehended so I will point out to you he is firing the cases and then discovering "However the cartridge fired and ejected but if you try to put the fired cartridge back 'the' cases will not chamber" in his first post, then he said it again just before you assured him he did nothing wrong.
Then you assumed he was using cases he found on the ground at a firing range.
F. Guffey
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Fire8523, said: “a fired cartridge would get stuck”. This is a common thread (as in thought) among WSM shooters and ULTRA MAG shooters, it seems they get into mortal combat with the press, die and shell holder when attempting to return the case back to minimum length. I always wonder ‘out loud’ if they are missing something like the case has more resistance to sizing than the press’s ability overcome the resistance. Being the check and balance reloader I check the gap between the bottom of the die and top of the shell holder when determining if the press won or if my cases are whipping my press.
Anything sticking out between the bottom of the die and top of the shell holder did not get pushed into the die.
F. Guffey
Anything sticking out between the bottom of the die and top of the shell holder did not get pushed into the die.
F. Guffey
Hi, F. Guffey,
"I can measure the length of a chamber with a unfired case..."
Of course you can. You can measure a chamber with a piece of stick or a ball pen. But if you cut a chamber to just accept that unfired case, the question is whether your chamber will accept cartridges of a different lot or from different makers. Those darned tolerances do make a lot of trouble.
Of course, IIRC, you once said you made your own cartridges to fit your own chambers, so the question of using factory ammo is moot in that case.
Jim
"I can measure the length of a chamber with a unfired case..."
Of course you can. You can measure a chamber with a piece of stick or a ball pen. But if you cut a chamber to just accept that unfired case, the question is whether your chamber will accept cartridges of a different lot or from different makers. Those darned tolerances do make a lot of trouble.
Of course, IIRC, you once said you made your own cartridges to fit your own chambers, so the question of using factory ammo is moot in that case.
Jim
Jim K. thank you.
“Those darned tolerances do make a lot of trouble”, Not for me, chamber length is .000”, meaning the chamber length is unknown or it is a ‘fill in the blank’ after measuring from the datum to the bolt face (datum, measured from).
Factory ammo? I have measured factory ammo. I have been impressed with factory ammo from Remington, variation in length from the shoulder to the head of the case has been .001”, that would make no sense to anyone that does not understand the variation is based on minimum length.
I purchased a mill from a collector, resource, reloader. at the time he was building a period correct 1911 Rock Island 03 rifle, he could not get a straight answer from a Springfield 1903, A3 etc., forum, for me? That was no surprise, I could only imagine, pick me! Pick me!
I offered help, he handed me a box of 15+ head space gages. I ask him about the ammo he planned to shoot in his new creation, he had a new box of Remington 30/06 ammo, I used his new ammo. The difference between the length of the chamber from the shoulder to the bolt face was and his new ammo was .0075, to correlate the difference in length between the go-gage and the chamber I used one of his go-gages, the difference was .0025.
I did all of that with a feeler gage, I offered to modify his go gages, I offered to demonstrate a technique that allows the use of a no go-gage when determining the length of the chamber, I also offered to do the same when using the filed reject gage, and I ask him if he had a new box of 280 Remington ammo, etc..
Then came time to solve his problem, he wanted a chamber that was go-gage length. He has no less than 80 Springfield bolts, I have no less than 30. I offered to check his bolts for their ability to reduce the length of the chamber, I did causation him the difficulty we would have finding a bolt that corrected his problem, + his Rock Island bolt had a straight handle for correctness, out of the 100 + bolts between us I have one in a Rock Island 03 and he had the one he was working with. Since then he has acquired 7 from other recourse people/another recourse person.
F. Guffey
“Those darned tolerances do make a lot of trouble”, Not for me, chamber length is .000”, meaning the chamber length is unknown or it is a ‘fill in the blank’ after measuring from the datum to the bolt face (datum, measured from).
Factory ammo? I have measured factory ammo. I have been impressed with factory ammo from Remington, variation in length from the shoulder to the head of the case has been .001”, that would make no sense to anyone that does not understand the variation is based on minimum length.
I purchased a mill from a collector, resource, reloader. at the time he was building a period correct 1911 Rock Island 03 rifle, he could not get a straight answer from a Springfield 1903, A3 etc., forum, for me? That was no surprise, I could only imagine, pick me! Pick me!
I offered help, he handed me a box of 15+ head space gages. I ask him about the ammo he planned to shoot in his new creation, he had a new box of Remington 30/06 ammo, I used his new ammo. The difference between the length of the chamber from the shoulder to the bolt face was and his new ammo was .0075, to correlate the difference in length between the go-gage and the chamber I used one of his go-gages, the difference was .0025.
I did all of that with a feeler gage, I offered to modify his go gages, I offered to demonstrate a technique that allows the use of a no go-gage when determining the length of the chamber, I also offered to do the same when using the filed reject gage, and I ask him if he had a new box of 280 Remington ammo, etc..
Then came time to solve his problem, he wanted a chamber that was go-gage length. He has no less than 80 Springfield bolts, I have no less than 30. I offered to check his bolts for their ability to reduce the length of the chamber, I did causation him the difficulty we would have finding a bolt that corrected his problem, + his Rock Island bolt had a straight handle for correctness, out of the 100 + bolts between us I have one in a Rock Island 03 and he had the one he was working with. Since then he has acquired 7 from other recourse people/another recourse person.
F. Guffey
Fire8523,
I vote for not not using cases for head space measurements, too many variables.
I suspect that 243winxb is on to something, take careful measurements of the fired case that will confirm chamber shape. I once reamed a chamber by hand and had the same symptoms, turned out to be reamer chatter, I could feel the flutes on the fired cases, when everything lined up the fired cases slipped in & out, otherwise the stuck.
mr
I vote for not not using cases for head space measurements, too many variables.
I suspect that 243winxb is on to something, take careful measurements of the fired case that will confirm chamber shape. I once reamed a chamber by hand and had the same symptoms, turned out to be reamer chatter, I could feel the flutes on the fired cases, when everything lined up the fired cases slipped in & out, otherwise the stuck.
mr
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