Can't stop breaking sizing dies !

[918v]

I think you should get bigger diameter dies. Apparently sizing the base .004” is causing too much stress on the dies. If you rebarrel with a tight chamber your sizing effort will be less but tight chambers cause pressure issues. So mitigating one problem will cause another.

 

[Florentoutang]

Gunsmith just called me, with the fired cartridge and the resized cartridge he sais me I have issue with my headspace.
According to him I have to set my die to respect the headspace of the chamber.
It surprises me ! For me, I have to make my die in contact with the shell holder, and I have not to worry about headspace if the gun is right...
What do you think about that ?
For me the rifle is wrong and not my reloading, but he says the opposite...

 

[918v]

Your gunsmith is correct. However bottoming out the die on the shell holder should not crack the die.

 

[Florentoutang]

Ok so how can I setup my die on the press to fix this headspace problem ?
If I unscrew the die I will probably not be able to chamber the resized cartridge...

 

[918v]

You have to measure the shoulder length on your fired case, then unscrew the die a little, size the case, measure the shoulder length, then screw in the die in small increments until you reduce the shoulder length by .002”. That way the case will chamber easily but you won’t be over sizing the case.
Do you have a shoulder length comparator? Or a 9mm pistol case?

 

[918v]

 

[Florentoutang]

If I resize with a die without contact with the shell holder I am not able to chamber my case... Just tried on a barrel I have at home.

So how can I do ? There's a problem with this method I think...

 

[Tokay444]

If I resize with a die without contact with the shell holder I am not able to chamber my case... Just tried on a barrel I have at home.

So how can I do ? There's a problem with this method I think...

That’s not the barrel you shot it from. Bump shoulder back .002” from fired. That’s it!
You’re literally breaking dies and trying to argue that you’re right and your gunsmith is wrong.

 

[Florentoutang]

Okey.
First, you don't know my gunsmith. In my country, I do with what I can have, and I really wonder if I can trust him. That's one of the reasons why I came here. How do you react if the only professionnal who can care of guns says "Oh 300 Norma mag is shit, my calibers are better", and stuff like that ?

On the other hand, I understand what you said, but if I am saying that I cannot chamber if I do not totaly resize, how would you chamber the case ? Maybe with a hammer ? Seems to be I nice idea !

On friday I'll check the chamber with propers gauges, compare my fired cases with my sized cases, and fired cases (lapua), so I should understand what's happening.

Now, what I think, is that my 86,5grs load at 920 m/s with my norma brass cause overpressures.
Seller of the gun loades exactly the same bullets, speed, powder, primers, but with lapua cases, and reached my speed with 89 grs of powder and had no extractions issues.
So I think the problem comes from the cases, who has different volume and does not support high pressures very well.

 

[1moaoff]

Always, always, always, always,always listen to what the rifle is telling you. Talk to the previous owner if possible. Compare his case to yours with measurements if possible. If your not measuring Everything you are guessing.
Could be chamber
Could be brass
Could be press

 

[TheOfficeT-Rex]

On the other hand, I understand what you said, but if I am saying that I cannot chamber if I do not totaly resize, how would you chamber the case ? Maybe with a hammer ? Seems to be I nice idea !

No. We're suggesting you measure, which is the complete opposite of a hammer. You just sound angry and frustrated.

On friday I'll check the chamber with propers gauges, compare my fired cases with my sized cases, and fired cases (lapua), so I should understand what's happening.

Are you new to reloading? I ask not to insult, but to understand your process. This is how most of us would have started - by measuring and setting the die by making measurements of the shoulder, using either a comparator tool or a 9mm shell as above. Very few on this site set the die by touch + 1/4 method that is listed in the die booklet.

I'm really here to figure out the mechanical circumstances that allowed you to crack three dies, not to comment on the repetition.

 

[lash]

On friday I'll check the chamber with propers gauges, compare my fired cases with my sized cases, and fired cases (lapua), so I should understand what's happening.

Hi,
I’ve been quiet on this thread until now, but I have to say that you really need to take a step back and review what you are doing before going forward anymore. By review, I specifically mean measure everything and compare everything properly. That’s how you will find out what is going on. Here is a good primer on brass preparation that starts out by instructing how to properly compare you fired cases to the new cases (it’s good, please read it):

Hand loading for Long range 1: brass case prep

Let's look at our cartridge brass first. Everything we do in hand loading is in the name of consistency, shot to shot. (Technically not "reloading" which is quick & expedient for the likes of short range speed shooting such as IPSC & Steel challenge shoots.) So there it is before us- a fine...

www.snipershide.com

There are a number of other great loading tutorials with pictures and step-by-step information in the Reloading sub-forum on this very site. Take a day to read, re-read and adsorb this information. You will be glad that you did so.

Here is the Reloading sub-forum:

Sniper's Hide Reloading

Open discussion on reloading, *always exercise caution* when reloading

www.snipershide.com

 

[spife7980]

Get measurements of the neck diameter, shoulder set back, shoulder diameter and base diameter in both the fired and sized conditions.

If you want to know a real answer then you need to get some real data. No one can tell you what you have except for yourself.

 

[Tokay444]

Okey.
First, you don't know my gunsmith. In my country, I do with what I can have, and I really wonder if I can trust him. That's one of the reasons why I came here. How do you react if the only professionnal who can care of guns says "Oh 300 Norma mag is shit, my calibers are better", and stuff like that ?

On the other hand, I understand what you said, but if I am saying that I cannot chamber if I do not totaly resize, how would you chamber the case ? Maybe with a hammer ? Seems to be I nice idea !

On friday I'll check the chamber with propers gauges, compare my fired cases with my sized cases, and fired cases (lapua), so I should understand what's happening.

Now, what I think, is that my 86,5grs load at 920 m/s with my norma brass cause overpressures.
Seller of the gun loades exactly the same bullets, speed, powder, primers, but with lapua cases, and reached my speed with 89 grs of powder and had no extractions issues.
So I think the problem comes from the cases, who has different volume and does not support high pressures very well.

It was shot in another chamber. Of course you’re can’t chamber it. Have you measured virgin cases? Fired, and your sized are only part of the equation. What others run in their guns is almost irrelevant. You’re breaking dies. You. Not them.

 

[918v]

If I resize with a die without contact with the shell holder I am not able to chamber my case... Just tried on a barrel I have at home.

So how can I do ? There's a problem with this method I think...

There is no problem with that method. That’s how we all do it. Measure the shoulder length, adjust the die to change the shoulder length by .002”

 

[Jake the dog]

Just some things to think about. Once the die contacts the shell holder, what does another quarter turn accomplish? Seems like it's already pushed the case in as far as it can go once it touches.
If you are pushing the shoulder back to far, the case is being shortend. If it's not able to move up and down, it's going to have to expand on the diameter, that brass has to flow to some where. After some number of cycles, say 100, the die, which doesn't have much meat anyway due to the magnum case, fatigues and cracks.
If you don't have comparators, there are videos in this forum about stripping your bolt and SLOWLY turning your die down until the bolt falls closed with no pressure.
The touch plus quarter turn isn't working for you. Try something else.
Full disclosure, I'm a newb at this, just now getting to 10 years, but there are smart, experienced people here who have given you good advice. At least consider what they are telling you and give it a try, or keep breaking dies. After 3, I would be skeptical of the method you have been using.

 

[918v]

“If you are pushing the shoulder back to far, the case is being shortend. If it's not able to move up and down, it's going to have to expand on the diameter, that brass has to flow to some where.”


Brass is able to move upward. It extrudes out the neck, requiring trimming.

 

[flyright]

The die can be shortened if it requires too much cam over to give a proper shoulder bump. First, measure everything as suggested above.

 

[Florentoutang]

Just some things to think about. Once the die contacts the shell holder, what does another quarter turn accomplish? Seems like it's already pushed the case in as far as it can go once it touches.
If you are pushing the shoulder back to far, the case is being shortend. If it's not able to move up and down, it's going to have to expand on the diameter, that brass has to flow to some where. After some number of cycles, say 100, the die, which doesn't have much meat anyway due to the magnum case, fatigues and cracks.
If you don't have comparators, there are videos in this forum about stripping your bolt and SLOWLY turning your die down until the bolt falls closed with no pressure.
The touch plus quarter turn isn't working for you. Try something else.
Full disclosure, I'm a newb at this, just now getting to 10 years, but there are smart, experienced people here who have given you good advice. At least consider what they are telling you and give it a try, or keep breaking dies. After 3, I would be skeptical of the method you have been using.

I consider all advices don't worry for it.
I will take time to mesure everything and try to understand what's happening.
When I started reloading this caliber, I followed reloadings who works with my .243 win and my .300 win mag.

Today, what I think is happening is :

- Overpressure
- Brass inflates on the bottom
- Have to reload with shell holder in contact to chamber again the brass
- Overpressure to reach my speed
again ang again.

I think that I'll try to fire some brass at low charges, and see if I can chamber them back. If it's possible, I'll be able to resize them with the die unscrewed, and so, respect my headspace.

 

[ormandj]

I consider all advices don't worry for it.
I will take time to mesure everything and try to understand what's happening.
When I started reloading this caliber, I followed reloadings who works with my .243 win and my .300 win mag.

Today, what I think is happening is :

- Overpressure
- Brass inflates on the bottom
- Have to reload with shell holder in contact to chamber again the brass
- Overpressure to reach my speed
again ang again.

I think that I'll try to fire some brass at low charges, and see if I can chamber them back. If it's possible, I'll be able to resize them with the die unscrewed, and so, respect my headspace.

Please, please, please, please stop. Take the measurements of the new and fired brass as directed by a dozen people here already and come back and post. All of the measurements suggested in this thread. Don’t do anything else at this point, you are wasting an enormous amount of time, effort, and money, and you are completely ignoring everyone here asking for simple measurements which will likely explain your problem, for unknown reasons.

People cannot help you, and you will continue cracking dies and potentially shooting something unsafe if you will not take these simple measurements and provide them. I apologize that I do not know your native language but again, please take all of the unfired and once fired but unresized brass measurements requested and post them here before you do anything else. Something is very wrong and you need to help isolate it before you just keep changing random things and repeating the same process breaking dies repeatedly.

I’ve never seen this in 20+ years of reloading, and I’ve seen cracked dies from others before. Never more than one, and it was always a chamber, die or press defect, or process issue. You’ve not provided enough information to rule out anything but die defect, simply because you’ve broken so many.

Again, please provide the measurements. That way we can try to help you isolate the actual problem, methodically, instead of randomly changing things.

 

[Florentoutang]

I said I'll do measurements tomorrow with a friend who have the tools.

And I will post them when I got it of course, so you will have it.

What I posted was just an hypothesis, and I'll wait for measures before doing anything.

I'm sorry, all of you seems to think that I call for help and don't listen for advices, but I listen. I try to make hypothesis to understand what's happening, this is my way of thinking.

 

[Jordanwickham]

One thing that you may not be aware of is there is a variance in shell holder contact. Theres a point where you can cause a real issue. There's a point where you go from a .002-.003 bump to a .005-.006 bump in a matter of a 1/8th of a turn on the die. You can usually feel this point because your cam over point goes from soft lock in to a stiffer ram stroke into a kind of pop feeling on the handle when you cam over.
As was stated before you can't base a die setting for a barreled action on your asymbled rifle based off of that chamber in that naked barrel you have laying on the floor.
You 100% have a headspacing issue. You are caming the press past the pop point not having any idea where you are bumping too.
A slight over headspace can flow out into the neck area but a massive over headspace can't flow into the neck and you end up trying to fit 10 lbs of shit in a 5 lb bag.
And if I read one of your posts correctly you said that the guy who sold you the gun reloaded the rifle at 89 but you can only get 86.5 grains in it? I don't know of any brass variation that would cause a 2.5 grain decrease in case capacity which leads me to believe you are bumping the shoulder back way too much.

 

[Florentoutang]

Hi guys, some news for you.

I measured with my friend who have (I think) a Whidden gauge for 300 norma, he said me I have no headspace issue. That's not what said my gunsmith.
GO gauge chambers well, NO GO gauge does not chamber, so chamber seems to be okey.

I tried to fore some brass with decreased charges, and signs of overpressures disappeared near 78 grs of ADI AR2225, equivalent of retumbo powder. This is WAY below classical charges who are near 84 or 83 grs with this powder and my bullet (225 grs eld-M).
Cases can chamber back in the rifle, nice point.

I think, and you could confirm, the only measurement who interests me is the headspace. Tell me if you want more to make an opinion.

I Made some measurements of that whith 2 cases I have : 9mm para and 45 ACP. These two cases permits me to measure at the smallest point of the shoulder (9mm) and at the middle of the shoulder (45 auto). Unfortunately, I am not able to measure the base of the shoulder.
Do not take a look on the value, I did not zeroed my tool. Just take a look on the differences.

I compilated all my measurements in excel to have a clear view of what's happening, you should have a picture.


What do you think about that ?

Jordan thanks for your post, I thought it was normal with my new press, the lee does not have these "pop" feeling, I'll be aware of that now.

 

[Steel head]

Maybe I don't get out much, but I've honestly never experienced or even heard of breaking a die, much less 3 of them.

I think there may be a gross mis-understanding of the process here. Hell, I used to neck resize and seat .338LM on a Lee hand press. Granted, it wouldn't bump or FLR, but I never had the expectation that it would, nor did I ever even try.

View attachment 7401095

I probably sized 1000 260 cases with my Lee hand press with no issues.

 

[Tokay444]

Where are your virgin case measurements?

 

[918v]

Hi guys, some news for you.

I measured with my friend who have (I think) a Whidden gauge for 300 norma, he said me I have no headspace issue. That's not what said my gunsmith.
GO gauge chambers well, NO GO gauge does not chamber, so chamber seems to be okey.

I tried to fore some brass with decreased charges, and signs of overpressures disappeared near 78 grs of ADI AR2225, equivalent of retumbo powder. This is WAY below classical charges who are near 84 or 83 grs with this powder and my bullet (225 grs eld-M).
Cases can chamber back in the rifle, nice point.

I think, and you could confirm, the only measurement who interests me is the headspace. Tell me if you want more to make an opinion.

I Made some measurements of that whith 2 cases I have : 9mm para and 45 ACP. These two cases permits me to measure at the smallest point of the shoulder (9mm) and at the middle of the shoulder (45 auto). Unfortunately, I am not able to measure the base of the shoulder.
Do not take a look on the value, I did not zeroed my tool. Just take a look on the differences.

I compilated all my measurements in excel to have a clear view of what's happening, you should have a picture.


What do you think about that ?

Jordan thanks for your post, I thought it was normal with my new press, the lee does not have these "pop" feeling, I'll be aware of that now.

So you’re reducing the shoulder length by .004”-.010”? And in the previous picture you drew, those were hypothetical numbers?

 

[Tokay444]

This thread makes my head hurt.

 

[Powder_Burns]

New piece of brass and a fired piece of brass

 

[acudaowner]

keep on buying more you will get it sooner or later I am guessing more later but keep the economy flowing you can do it . do you only break one type got my fingers crossed for you if your breaking only one try harder others calibers need love too .

 

[lash]

@Florentoutang, it really does seem to me, looking back at what you are posting, that you are spending a good amount of effort to prove that it is not you, but your equipment, gunsmith, chamber or other. In almost every case when investigating root cause of a problem, one must consider the possibility that what one is doing might be incorrect. In this case, it is almost assured that you are doing something wrong. Sorry to break that to you.

In this case, the very first thing that you are doing wrong is that you are not measuring. Measure everything! All the time! At least until you get control of the issue/problem.

I’m going to post this again, in the probably vain hope that you’ll actually read it:

Hand loading for Long range 1: brass case prep

Let's look at our cartridge brass first. Everything we do in hand loading is in the name of consistency, shot to shot. (Technically not "reloading" which is quick & expedient for the likes of short range speed shooting such as IPSC & Steel challenge shoots.) So there it is before us- a fine...

www.snipershide.com

Like everything else in long range shooting, if you do not have the fundamentals down, your success will be a long time coming, if at all. In this case, you need to learn the fundamentals of loading.

I’ll say it once again, “You need to learn the fundamentals of loading.”

This is not an attack on you. This is sincere and an attempt to help you understand and solve your problem. You are NOT measuring and recording what you should be measuring and recording. Until you begin to do so and to understand why it is that you need to do so, everything you are doing is random and finding your problem is just an exercise in frustration for the good members here that are trying to help you help yourself.

Cheers!

 

[Florentoutang]

Hey guys, I know my english is not very well, but you can do efforts... I Already replied to all of your comments... So let's do it again...

Where are your virgin case measurements?

Don't have virgin cases. Does not exists on my island. Now, I only have fired cases in MY chamber, and resized cases. Virgin cases will arrive in approx 3 weeks.

So you’re reducing the shoulder length by .004”-.010”? And in the previous picture you drew, those were hypothetical numbers?

Non hypothetical measurements, measurements on only 2 brass, one fired one resized.
On my measurements you can see fluctuations then, I calculated average, min and max differences.

View attachment 7407806
New piece of brass and a fired piece of brass

Dont have new brass on my island. Already measured and posted this. Around 0,004" ou 0,005".

@Florentoutang, it really does seem to me, looking back at what you are posting, that you are spending a good amount of effort to prove that it is not you, but your equipment, gunsmith, chamber or other. In almost every case when investigating root cause of a problem, one must consider the possibility that what one is doing might be incorrect. In this case, it is almost assured that you are doing something wrong. Sorry to break that to you.

In this case, the very first thing that you are doing wrong is that you are not measuring. Measure everything! All the time! At least until you get control of the issue/problem.

I’m going to post this again, in the probably vain hope that you’ll actually read it:

Hand loading for Long range 1: brass case prep

Let's look at our cartridge brass first. Everything we do in hand loading is in the name of consistency, shot to shot. (Technically not "reloading" which is quick & expedient for the likes of short range speed shooting such as IPSC & Steel challenge shoots.) So there it is before us- a fine...

www.snipershide.com

Like everything else in long range shooting, if you do not have the fundamentals down, your success will be a long time coming, if at all. In this case, you need to learn the fundamentals of loading.

I’ll say it once again, “You need to learn the fundamentals of loading.”

This is not an attack on you. This is sincere and an attempt to help you understand and solve your problem. You are NOT measuring and recording what you should be measuring and recording. Until you begin to do so and to understand why it is that you need to do so, everything you are doing is random and finding your problem is just an exercise in frustration for the good members here that are trying to help you help yourself.

Cheers!

Okey, now my turn. This is not an attack on you. This is sincere and an attempt to make me understand and solve my problem.
I read what you posted, and I saw I did mot measure headspaces on my resized brass. new thing learned, youhou !
My new post is consecrated on measurements. Did you read this ?

I have the feeling that you keep saying "you know anything john snow", but you are not involved into teaching anything.
I'm sorry, I'm physics teacher, but maybe you could send me an URL on how to teach something ? And at least, john snow had sex...


Ok now, I say it.
I've done some measurements, who seems to be interestings.
I dit an experience who, I think, is interesting.
And none of your replies does speak about these informations. What is going wrong ?

I was so happy to post my nice measurements with averages values of the headspace, and I was sure this time, you will give me your feeling about my measurements... Thanks for hope...

 

[TheOfficeT-Rex]

I think, and you could confirm, the only measurement who interests me is the headspace. Tell me if you want more to make an opinion.

I Made some measurements of that whith 2 cases I have : 9mm para and 45 ACP. These two cases permits me to measure at the smallest point of the shoulder (9mm) and at the middle of the shoulder (45 auto). Unfortunately, I am not able to measure the base of the shoulder.
Do not take a look on the value, I did not zeroed my tool. Just take a look on the differences.

I compilated all my measurements in excel to have a clear view of what's happening, you should have a picture.


What do you think about that ?

The headspace measurements are a good start, but I would also like to see a measurement near the base of the case (case diameter).

From your measurements, I am referencing the ones made with the 45 case - measuring halfway down the shoulder is a good way to measure effective headspace and sizing, or bump.

I am concerned that you are moving the shoulder back too far. An average of ,008" is quite far. We usually want this number to average ,002. Try to unscrew the die in the press to produce a ,002 difference between the fired case (unsized) and resized case, when measured with the same 45 shell. If you resize your cases by ,002 smaller than fired, you should find that they still chamber easily.

I think you have the die set too low in the press. This could be the reason why you are breaking dies.

 

[lash]

Hey guys, I know my english is not very well, but you can do efforts... I Already replied to all of your comments... So let's do it again...



Don't have virgin cases. Does not exists on my island. Now, I only have fired cases in MY chamber, and resized cases. Virgin cases will arrive in approx 3 weeks.


Non hypothetical measurements, measurements on only 2 brass, one fired one resized.
On my measurements you can see fluctuations then, I calculated average, min and max differences.



Dont have new brass on my island. Already measured and posted this. Around 0,004" ou 0,005".



Okey, now my turn. This is not an attack on you. This is sincere and an attempt to make me understand and solve my problem.
I read what you posted, and I saw I did mot measure headspaces on my resized brass. new thing learned, youhou !
My new post is consecrated on measurements. Did you read this ?

I have the feeling that you keep saying "you know anything john snow", but you are not involved into teaching anything.
I'm sorry, I'm physics teacher, but maybe you could send me an URL on how to teach something ? And at least, john snow had sex...


Ok now, I say it.
I've done some measurements, who seems to be interestings.
I dit an experience who, I think, is interesting.
And none of your replies does speak about these informations. What is going wrong ?

I was so happy to post my nice measurements with averages values of the headspace, and I was sure this time, you will give me your feeling about my measurements... Thanks for hope...

As a physics teacher, do you write everything that your students read or do you assign chapters in well established physics books for them to read and learn? I rather think the latter. In the same way, I pointed you in the direction of some of the best documented information on how to build proper precision rifle loads. If you did not learn from that (though you have already said that you did), then is it my fault for having led you to water or yours for not having drunk that water?

Now, onto your issue. @TheOfficeT-Rex has given you your next step in the process of correcting your issue. I suggest you follow his advice.

 

[Florentoutang]

The headspace measurements are a good start, but I would also like to see a measurement near the base of the case (case diameter).

From your measurements, I am referencing the ones made with the 45 case - measuring halfway down the shoulder is a good way to measure effective headspace and sizing, or bump.

I am concerned that you are moving the shoulder back too far. An average of ,008" is quite far. We usually want this number to average ,002. Try to unscrew the die in the press to produce a ,002 difference between the fired case (unsized) and resized case, when measured with the same 45 shell. If you resize your cases by ,002 smaller than fired, you should find that they still chamber easily.

I think you have the die set too low in the press. This could be the reason why you are breaking dies.

Measuring the base of the case was the first thing I dit when I saw that I was not able to chamber back. I have a difference around 0,003", 0,004" maximum.
If I cannot chamber, I was forced to full full full resize to be able to chamber, because of the bottom of the brass.

Than, I agree with you, I think I bumb my shoulder back too far. This causes overpressure I ignored, and I entered in a bad circle that I described some posts earlier.

Next experiment will only be neck sizing brass who can chamber back, and check at what charge I can reload them whithout overpressures.

 

[TheOfficeT-Rex]

Next experiment will only be neck sizing brass who can chamber back, and check at what charge I can reload them whithout overpressures.

No need to change to neck sizing only, just unscrew the die to get the proper ,002 sizing difference. Size with this new setting each time.

I bet they will chamber in your rifle and will be just fine for pressure.

 

[Florentoutang]

As a physics teacher, do you write everything that your students read or do you assign chapters in well established physics books for them to read and learn? I rather think the latter. In the same way, I pointed you in the direction of some of the best documented information on how to build proper precision rifle loads. If you did not learn from that (though you have already said that you did), then is it my fault for having led you to water or yours for not having drunk that water?

Now, onto your issue. @TheOfficeT-Rex has given you your next step in the process of correcting your issue. I suggest you follow his advice.

I don't use books, I write everything. My work as a teacher is to modify science to make it understandable for my students.

I'm sorry to be a little bit angry, but I seriously have the feeling that you have the feeling that I do not consider advices because you don't consider what I say on my posts.
May be missunderstandings because of language.

I developped my loading method by reading books, and taking informations in different places. I mixed up all informations to have my method who works very well for :
243 win
300 win mag
30-30 win.

Never had issues, and my 300 win mag hits easely at 1200m.

Now I have a new problem, so I read what your saying, and I try to understand what's happening. I think I have something, but is surprises me.
How full length resize with contact with the shell holder (method described on many french books), could be dangerous and cause such an overpressure ?
My chamber is good, so tools are to small to be safe I presume...
Or french books says shit ?

This is what I try to understand now...

 

[Florentoutang]

No need to change to neck sizing only, just unscrew the die to get the proper ,002 sizing difference. Size with this new setting each time.

I bet they will chamber in your rifle and will be just fine for pressure.

That is what I'm going to do now.
Neck sizing only will just be an experiment to eliminate totally shoulder bump.
If I can charge around 84 grs of powder without ejection and chambering issues, I will be sure my headspace is the problem.
If I can not charge like that without overpressure, I think I can say that norma brass are not good brass.

In around 3 weeks I will recieve new lapua brass, so if I reload without headspace issues, I should be able to charge at 89 grs of powder as the former owner of the gun.

 

[lash]

I understand that the former owner of the gun was using 89 grains charge and appreciate that you have information that gives you a baseline for your load. Are you using the same brass that the previous owner used? Same brand and lot number? Or not, and that is why you are awaiting Lapua brass?

I ask because different brass brands and sometimes even different lots of brass vary in weight, water volume and therefore loads that work in them. This is why load development always starts lower (typically a 10% lower charge) and works back up to suggested charge, checking for pressure signs as you go.

One can never assume that what load works for one person works for another, even in the same rifle, unless you are using the exact components that the previous owner was using. This includes the same lot of powder, as powder can vary from lot# to lot#.

 

[ormandj]

That is what I'm going to do now.
Neck sizing only will just be an experiment to eliminate totally shoulder bump.
If I can charge around 84 grs of powder without ejection and chambering issues, I will be sure my headspace is the problem.
If I can not charge like that without overpressure, I think I can say that norma brass are not good brass.

In around 3 weeks I will recieve new lapua brass, so if I reload without headspace issues, I should be able to charge at 89 grs of powder as the former owner of the gun.

I'm not even going to get into the rest of the details in your posts, but I thought you said you had headspace of your rifle measured and it was fine? Or do you mean cartridge headspace with you potentially over-resizing your brass and setting back the shoulders too far (which would 100% explain everything you've described to include 3 cracked resizing dies)? Just get a tool to measure a fired case vs. resized case and you'll know. There's a lot of options, here's a few: http://bulletin.accurateshooter.com/2019/10/hows-your-headspace-four-tools-to-measure-shoulder-bump/

Checking proper shoulder setback by firing and looking for ejection and chambering issues is attacking the problem from the completely wrong angle. Measure your shoulder setback, and keep it 0.002" as mentioned by others. Once you've confirmed you're properly sizing brass, then worry about working up loads. Also, don't get hung up on the former owner's numbers, there are way too many variables including the potential for exaggerated truths to make something look different than it really is. What does load data look like for that cartridge with the powder/bullet you are using?

 

[Florentoutang]

I understand that the former owner of the gun was using 89 grains charge and appreciate that you have information that gives you a baseline for your load. Are you using the same brass that the previous owner used? Same brand and lot number? Or not, and that is why you are awaiting Lapua brass?

I ask because different brass brands and sometimes even different lots of brass vary in weight, water volume and therefore loads that work in them. This is why load development always starts lower (typically a 10% lower charge) and works back up to suggested charge, checking for pressure signs as you go.

One can never assume that what load works for one person works for another, even in the same rifle, unless you are using the exact components that the previous owner was using. This includes the same lot of powder, as powder can vary from lot# to lot#.

The problem I had while developping load for the 300 norma mag is the absence of load datas.
I took a look on charges used by guys on this forum (a thread is dedicated), and I developped my charge from 83 grs to overpressure signs (in my case, brass hard to extract).
I was affraid of going down in the charge because I had not start loads data. But with these brass, my start load was overpressured.
I can't explain it to myself, I ignored overpressures signs (little marks on primer, brass marked by ejector), and I think this was the start of my trouble.

Now, I can't wait to recieve lapua brass because, first, they are new, and second, I want to compare charges I'm able to have with lapua brass and norma brass.

 

[Florentoutang]

I'm not even going to get into the rest of the details in your posts, but I thought you said you had headspace of your rifle measured and it was fine? Or do you mean cartridge headspace with you potentially over-resizing your brass and setting back the shoulders too far (which would 100% explain everything you've described to include 3 cracked resizing dies)? Just get a tool to measure a fired case vs. resized case and you'll know. There's a lot of options, here's a few: http://bulletin.accurateshooter.com/2019/10/hows-your-headspace-four-tools-to-measure-shoulder-bump/

Checking proper shoulder setback by firing and looking for ejection and chambering issues is attacking the problem from the completely wrong angle. Measure your shoulder setback, and keep it 0.002" as mentioned by others. Once you've confirmed you're properly sizing brass, then worry about working up loads. Also, don't get hung up on the former owner's numbers, there are way too many variables including the potential for exaggerated truths to make something look different than it really is. What does load data look like for that cartridge with the powder/bullet you are using?

Yep I agree, but now, if I want to continue shooting these brass I have to fireform them, because they are all resized with the wrong headspace.
And brass who are not resized yet does not chalber because of overpressure, so I have to resize them on the bottom. And sizing the bottom of the case enough to chamber bumps my shoulder back too much.

So what I have to do is fireform them with a cool charge to be able to chamber them back, and have the good headspace.

There is not load datas for 300 norma mag with my powder and my bullet.
Loads should be around 83 to 91 grs of powder.

 

[lash]

Try this, one round each:

83.2
84.0
84.8
85.6
86.4
87.2
88.0
88.8

You already know that 89 is too hot for your current brass. Start with the low charge and pay attention to developing pressure signs as you work up. It would be great if you could also measure and record velocity at the same time. You will find out where your hot load is.

 

[Florentoutang]

83,2 is too hot too.
With sized die I started to be comfortable around 78 grs. And I think I'll fireform around 76 grs. to have a very smooth chambering of fired brass.
When brass will be fireformed, i'll check headspace to be sure this is back at the good value, and I will charge them around 83 grs as you said to check if I'm able to charge them as I should.

 

[918v]

I would end this nightmare by setting the barrel back and rechambering with a tighter reamer.

 

[ormandj]

I would end this nightmare by setting the barrel back and rechambering with a tighter reamer.

Why, when all he needs to do is adjust his resizing die? Rechambering isn’t going to fix his dies cracking when having them extended too far...

 

[918v]

His dies aren’t cracking because they’re extended too far

 

[TheOfficeT-Rex]

His dies aren’t cracking because they’re extended too far

I'm dumb or I skipped over it. What's causing it?

 

[918v]

His cases are too fat after firing and the die walls are too thin to handle the pressure from sizing. If he had a tighter chamber his brass would come out skinnier and would be easier to size.

 

[ormandj]

His dies aren’t cracking because they’re extended too far

He’s attempting to over size his brass, dies set wrong or chamber cut wrong. I think it’s less likely he has a chamber cut improperly than he has a die misadjusted, don’t you, especially if his story of other loaders having no issue is true? It’s certainly a much easier thing to check and fix. The only time I’ve ever seen a die crack has been when misadjusted in a press.

I won’t say there’s no way his chamber is cut wrong with the crazy stuff we’ve all read here, just that die misadjustment seems a whole lot more probable.

 

[918v]

Did I say his chamber is cut wrong?
What is cracking his die is outward pressure from the case being sized, not from the shell holder pushing on the bottom of the die.