What is my Brass telling me?

T

Torchy

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May 29, 2017
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#1
So shooting a new rifle and I am noticing pressure signs early I think.

I shot roughly my 100th to 145th rounds (45 rounds total) yesterday and grabbed some data. Basically these are conservative loads yet I am seeing slight ejector swipes.

Virgin Peterson, base to shoulder is stretching .013 to .014 once fired.

300Norma Mag, H1000, SMK230gr, CCI250
82.2gr of H1000 and is averaging about 2880fps, which is not fast. Some of these had a slightly heavier bolt lift. This was a seating depth test but that had little impact on velocities.




This was OCW with Berger 230 hybrids. 81.0-82.2gr of H1000 and still you can see slight ejector marks. Virgin Peterson. Average about 2890fps. The 82.2 had slightly heavier bolt lift. Lightest load left to heaviest load far right.





For comparison, I shot 10 rounds of virgin Lapua that day too. Virgin to fired on the Lapua has .005-.006 stretch from base to shoulder
N565, 77.0 and 78.0gr (very conservative), FGMM primers, SMK230. average 2720ish feet per second. These did not have a heavy bolt lift at all but still faint swipes.


Well we all like pics right?


Is this just the nature of a magnum? Never owned one. Am I doing something wrong?
 
#4
Lots of pictures and lots of text that could be boiled down to the simple fact that you are dangerously close to the edge of overpressure. Look at your primers man.........:eek:

One of your statements that is very concerning; "300Norma Mag, H1000, SMK230gr, CCI250, 82.2gr of H1000 and is averaging about 2880fps, which is not fast". So, you don't think the load is fast, but you are ignoring multiple pressure signs. Does this mean that you will continue to ignore worsening pressure signs while increasing loading in order to get to velocities above where you are now ? Pretty bad idea, if that's what you are thinking.
 
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#6
rtB said:
Looks to me like you're testing too many things.

1 brass
1 powder
1 bullet
1 primer
1 seating depth

Incremental charges.

Can't test 4 different things at one.
Click to expand...
Wasn't very clear in the OP. I had already done some OCW before all this with SMK 230 (all with same seating depth) but without labradar. Also had some success during that first round of OCW so the Peterson SMK batch was to test seating depth because I liked my charge although it's low compared to most. Also noticed the pressure signs so I was a little confused.

So decided to chrono this round of SMK seating depth testing (since I should have the first time but didn't have the time). Well I had time to make some more rounds so i decided to make the Bergers for an OCW in the same Peterson brass (all had same seating depth). Had a rough idea of seating depth due to the good results from the original smk ocw.

Then I just so happen to get my new shipment of fgmm primers, N565 and lapua brass sooo I wanted to try those out too. So among all these different components, I am at different testing stages in development. Basically I agree and am testing incrementally, one change at a time.

Common thing I found in all this was pressure signs across the board. The N565 was at V V recommended starting weight of 77.0gr and I saw the faintest ejector swipe but bolt did not feel heavy. Just seems like I am getting pressure signs on this rifle when I shouldn't be.

In the midst of all this I took note of my brass stretch but IDK what it means.

My questions:
What could cause early pressure signs?
Whats a normal amount of brass stretch?
 
#7
Threadcutter308 said:
Lots of pictures and lots of text that could be boiled down to the simple fact that you are dangerously close to the edge of overpressure. Look at your primers man.........:eek:

One of your statements that is very concerning; "300Norma Mag, H1000, SMK230gr, CCI250, 82.2gr of H1000 and is averaging about 2880fps, which is not fast". So, you don't think the load is fast, but you are ignoring multiple pressure signs. Does this mean that you will continue to ignore worsening pressure signs while increasing loading in order to get to velocities above where you are now ? Pretty bad idea, if that's what you are thinking.
Click to expand...

This post is basically for the exact opposite. Manufacturer starting load, 77.0 gr of N565 (VV), I am seeing faint pressure signs there. Seems odd.

Compared to most guys pet load in this config, their all at 84-87gr of H1000 and I am at 82.2gr. Given the same bullet I am 100-200fps slower with pressure so really even slower.

Don't intend to go higher, but seems early and I wanna know why.
 
#9
Heavy bolt lift ( or any sign of using force to lift the handle ) is a clear and present sign of overpressure!!!
Primers are not good at indicating anything, as there are a lot of factors involved here, but when you got a mark from the ejector ( any size ), then be warned!!!!!
Step back at least one grain of powder and start working with the seating dept instead.
A high V/o is not essential but a low ES is and you should allways be aware of this.
Playing in the borderlands with a magnum, is like tickeling a dragons tail, you never know when you are going to be eaten.
And as for the brass: If a case has been subjected to overpressure, it's done! it should never be used again.
 
#10
Flat primers, meh. Some primers cratered and some not, look the fuck out.

Your brass is telling you , you are making way too much pressure. At the range it was telling you, stop fucking shooting me and figure out why I am way over pressure. This is a 101 problem. You don't need help from a forum, you need to go back to the basics and start learning the very first things about reloading. I don't care what velocities others make and how much powder they use. Reloading is an individual process for each gun.

I am glad you didn't have a catastrophic failure, and that you came here to get scolded before you did. For future reference, when you see ejector swipes, extractor marks, and cratered primers it is past time to stop shooting that ammo.

I bet most of that brass will no longer hold a primer.
 
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#12
Are you certain your chamber is free of any oils or solvents? Are you certain lube has been removed from your brass? Those issues can cause false pressure signs.
 
#13
You are getting a ton of gloom and doom. First thing I would do is clean the barrel once more. Then see how the fired brass feels being chambered empty. Grab some measurements, size about 20 pcs(10 of each brand) that are not marked up with minimal bump. Then pull a half gr of grain of powder, load five of each and reshoot.
New brass has a tendency to get slammed hard into the bolt face and exhibit false pressure signs. IMO, your primers do not look that bad, plus they are not the greatest indicator.
 
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#14
I always go easy on the first firing of brass.
A lighter load while barrel is speeding up and fire forming brass I feel helps the life of both.
I found out magnum cases are more particular about case/chamber having any lube on them than my smaller cartridges.

You have issues with those cases getting marked like that.
You need to find out why pronto.


I suggest simplifying your components used till you get it sorted.
You may just have a slow barrel.
 
#15
Milo 2.5 said:
You are getting a ton of gloom and doom. First thing I would do is clean the barrel once more. Then see how the fired brass feels being chambered empty. Grab some measurements, size about 20 pcs(10 of each brand) that are not marked up with minimal bump. Then pull a half gr of grain of powder, load five of each and reshoot.
New brass has a tendency to get slammed hard into the bolt face and exhibit false pressure signs. IMO, your primers do not look that bad, plus they are not the greatest indicator.
Click to expand...

^^^
This

I would also back off the lands. Often there is a pressure spike upon ignition that causes pressure signs with what are normally considered starting loads just because you are too close to the lands. Heavy for caliber bullets like to be far away from the lands if you want your cases to last. Then there’s lot to lot variation if H1000. Maybe you have a fast burning lot. Try a slower burning powder.
 
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#17
Milo 2.5 said:
Also, way too much growth on the peterskin
Click to expand...

CD1BE296-5388-4EB1-B9D2-13ACDF99C679.gif
 
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#19
I am lost as to why you are firing 2 different brands of brass, pick one or the other. If you have more new Peterson to fire, pull 2-3gr of powder and jam that bullet 10 thou into the lands, it needs to be fully fireformed in that chamber, you are pissing in a fan at this time with it.
 
#20
Milo 2.5 said:
You are getting a ton of gloom and doom. First thing I would do is clean the barrel once more. Then see how the fired brass feels being chambered empty. Grab some measurements, size about 20 pcs(10 of each brand) that are not marked up with minimal bump. Then pull a half gr of grain of powder, load five of each and reshoot.
New brass has a tendency to get slammed hard into the bolt face and exhibit false pressure signs. IMO, your primers do not look that bad, plus they are not the greatest indicator.
Click to expand...
Yeah pretty easy to tell some didn't read my words.

I'm cool with cleaning it again although it look pristine clean from my bore scope. Basically didn't even see copper in there. Whis I could get a pic of that.
 
#21
Juggerxxx said:
Are you certain your chamber is free of any oils or solvents? Are you certain lube has been removed from your brass? Those issues can cause false pressure signs.
Click to expand...
Yes I am an absolute freak about these things to the point that I went out and bought a Hawkeye. Also I wet tumble and dry to remove lube, then give 2 days to dry before I even attempt to do more steps in the brass prepping process. And yea I know wet brass or chamber can give a false positive.
 
#22
918v said:
^^^
This

I would also back off the lands. Often there is a pressure spike upon ignition that causes pressure signs with what are normally considered starting loads just because you are too close to the lands. Heavy for caliber bullets like to be far away from the lands if you want your cases to last. Then there’s lot to lot variation if H1000. Maybe you have a fast burning lot. Try a slower burning powder.
Click to expand...

Might be distance to the lands. I know that can cause pressure if their close. Also that is one common thing in all my loads but I'm over 30 thou off. Maybe I should go further away. As far at lot, it's looking like par for the course compared to literally everyone else on this forum. If anything it seems slow compared to everyone else hence this thread.
 
#23
Milo 2.5 said:
Also, way too much growth on the peterskin brass. Your have carbon on the shoulder from not sealing off, probably gassing the whole chamber as the case heads have carbon buildup on the marks created by the bolt face.
Click to expand...
So that is a question I had which it did seem like more than normal stretch. The fired Peterson will fall directly into the chamber without me pushing it in. It will not fall out on it's own with I flip the open chamber muzzle up for it to fall out. I did not measure body diameter from virgin to fired so maybe I'll do that but can't be much because the brass will fall completely in with only needing a finger nudge in the last few thou.

Very interesting to know about how carbon can make it to the case head. Did not know that.
 
#24
Torchy said:
So that is a question I had which it did seem like more than normal stretch. The fired Peterson will fall directly into the chamber without me pushing it in. It will not fall out on it's own with I flip the open chamber muzzle up for it to fall out. I did not measure body diameter from virgin to fired so maybe I'll do that but can't be much because the brass will fall completely in with only needing a finger nudge in the last few thou.

Very interesting to know about how carbon can make it to the case head. Did not know that.
Click to expand...
I'm not backreading now, but if you had any resistance lifting the bolt on Peterson brass, the cause was carbon from gas escaping(not going out the muzzle)
 
#25
Precision Underground said:
All the peterson 300 Norma brass I have had was small from the factory. One lot was so small I could hardly get the extractor to grab it. I'm pretty sure this can mimic over-pressure when the brass grows can't it?
Click to expand...
Hmm interesting. The brass I have is some of their first lots made. I got on this 300NM train early but am just now really diving into this caliber.

To possibly further this theory, my Peterson had .013-.014 stretch and the Lapua had less than half that at .005-.006. The Lapua did not have heavy bolt lift but had a very very conservative load which was manufacturers starting load of 77gr. It was also 200+ fps slower than H1000.

MY BIG MYSTERY IS, then why did the Lapua still show faint ejector swipes at starting load with a slow fps. Maybe 30thou off lands is still too close? Maybe it has something to do with the can? Have not tried shooting without a can. Well I have but it was a while back. Basically I got this rifle, did very light break in loads (78gr of H1000) to break it in and went into OCW testing. Well I shelfed this whole rifle for over a year and am just now getting back into this rifle. That's why I cant remember what all fully transpired on my first round of OCW.

Also I love your stuff. Have 2 of your bags and used it to shoot these in the pics!
 
#26
Milo 2.5 said:
I am lost as to why you are firing 2 different brands of brass, pick one or the other. If you have more new Peterson to fire, pull 2-3gr of powder and jam that bullet 10 thou into the lands, it needs to be fully fireformed in that chamber, you are pissing in a fan at this time with it.
Click to expand...
Sure good question, I got into this caliber early and before Lapua brass was out. In 2018 Lapua told me at SHOT that their brass would be out soon. So had the rifle but no Lapua brass so I bought 125 pieces of Peterson to hold me over and have something to shoot until the Lapua came out. Just bought and prepped 400 pieces of Lapua so the Peterson will pretty much be shelfed but already had em loaded to shot them.

Moving forward I'll only be using the Lapua in the rifle and especially since they seem to fit my chamber more than double better than Peterson.
 
#29
Torchy said:
MY BIG MYSTERY IS, then why did the Lapua still show faint ejector swipes at starting load with a slow fps.
Click to expand...
I enlarged your pic, I do not a see swipe. But a swipe on the outer edge of case head is different than an ejector mark. The marks on the outside of caseheads comes from the extractor, or a dirty bolt face, clean the bolt face. Like I said earlier, I bet most of your issues disappear on once fired brass.
If you look close on your Peterson brass, the swipe as you call is from rotation, or failure to rotate on extraction.
 
#31
Torchy said:
Thought can could increase chamber pressure slightly due to gases not being able to escape as fast as they could if the can was not there.
Click to expand...
I have seen that in a dasher sized case, so I cannot say you are wrong. But it is your brass dimensions here for the majority of it. Hey either FF your Peterson brass with a jam, or move forward with Lapua like you want to.
 
#32
Milo 2.5 said:
I enlarged your pic, I do not a see swipe. But a swipe on the outer edge of case head is different than an ejector mark. The marks on the outside of caseheads comes from the extractor, or a dirty bolt face, clean the bolt face. Like I said earlier, I bet most of your issues disappear on once fired brass.
If you look close on your Peterson brass, the swipe as you call is from rotation, or failure to rotate on extraction.
Click to expand...
Ya know what, I did clean my bolt and yes it was a lil dirty. Yes I see the extractor and ejector marks on the Peterson Cases. I have another pic of the Lapua but there is the faintest of faint "ejector" marks on some of the Lapua:(Their both more pronounced on the Peterson.

Thanks for the info on rotation. Didn't know that. All said I'm getting a feeling of a combo of a few things. Virgin brass, Peterson being a lil out of spec, dirty bolt and I might just have a slow barrel. I relooked at all of everyone elses data and I'm not that far off from them. Might just have to accept that this just be a slow rifle because I am a safe/conservative loader.

5 on left are 77gr. 5 on the right are 78gr. Max weight per manufacturer is 78.9gr FWIW

 
Last edited:
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#36
I could have written the exact letter except 260 rem and Rel 16. Also I could throw in a curious difference in CCI and Winchester primers. My conclusions are:
A)Go very very light powder charge on the first loading of Peterson brass
B)Winchester srp do not crater compared to CCI srp
C)Wear shooting glasses, I got sprayed in the nose last week, inch higher I'd be in tuff shape
D)Work up an accurate not too hot load and stick with it. Changing anything results in a lot tail chasing
E)Accuracy without excessive pressure over velocity (I really struggle with this one as I have a super accurate too hot load that I had to shelve)
F)The best thing about Peterson brass is it doesn't stick in a case holder after a too hot firing. Lapua brass does.
G)Load 5 to 10 test rounds instead of 50. Pulling bullets is a pain.
H)Always test fire to confirm obvious theories, I'm always amazed at how many surprises I get.
I)Experience is the result of poor judgement
 
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#37
Torchy said:
Word.

It's a Cadex complete build rifle so Cadex action. Appreciate all the help. Think I have it figured out and have better direction now. Thanks again (y)
Click to expand...
Nice rifle! Good job on the Hawkeye too, I am going to buy a teslong to compliment mine. Just don't try to solve world issues with it. unless, unless you get the opportunity to peek inside schiffs head and see just what the pea is bouncing off of.
With that big of case, and the weight of your bullet, I'd look at a slower powder. Not sure how else to put it, but you are getting a quick "whap" as opposed to a slower "thump", and it changes the dynamics of things.
 
#38
I took a even closer look at your brass and noticed, that there are some alarming signs on the Peterson sample, besides the ejectormarks.
The extractor may have had an VERY good grip in the groove and i think you should consider the use of safety glasses, very carefully, if you keep using that load.
The pressure has been so high, that the brass has started floating and the next step could be a case rupture, which in a Magnum will be catastropic.
A guy, known to me, had a Sako 75 in 7mm RM and looked like this, after a case rupture.
sako 75 rupture 3.JPG
 
#39
Milo 2.5 said:
Nice rifle! Good job on the Hawkeye too, I am going to buy a teslong to compliment mine. Just don't try to solve world issues with it. unless, unless you get the opportunity to peek inside schiffs head and see just what the pea is bouncing off of.
With that big of case, and the weight of your bullet, I'd look at a slower powder. Not sure how else to put it, but you are getting a quick "whap" as opposed to a slower "thump", and it changes the dynamics of things.
Click to expand...

I hear ya. I'll most certainly heed more caution.

And what is a Teslong? Is it something that can put my Hawkeye onto a screen or phone? Because I really want that and am not loving Hawkeyes antiquated option.
 
#40
Bemoni said:
I took a even closer look at your brass and noticed, that there are some alarming signs on the Peterson sample, besides the ejectormarks.
The extractor may have had an VERY good grip in the groove and i think you should consider the use of safety glasses, very carefully, if you keep using that load.
The pressure has been so high, that the brass has started floating and the next step could be a case rupture, which in a Magnum will be catastropic.
A guy, known to me, had a Sako 75 in 7mm RM and looked like this, after a case rupture.
View attachment 7244070
Click to expand...
Geez man that's crazy. What does floating brass mean?
 
#42
It happens when the pressure is getting higher than the dimensions on the shellcase are designed for ( like a boiler without safetyvalve ), then something has to move and give way.
And brass is by nature very easy to manipulate, just by mechanical force, so when the pressure is rising inside the case, this will expand to a certain degree and retract again, when the pressure goes down.
But, if the pressure is higher than the design allows, the case material may start moving, by the most convinient way and that's usually through a unsupported area, such as the the primer pocket or the rim, releasing most of the gas, from the combustion, somewhere it really hurts.
Sorry if there are some typos and grammars, i'm not use to write this in english, but i'm trying my best.
 
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#43
Torchy said:
Hmm interesting. The brass I have is some of their first lots made. I got on this 300NM train early but am just now really diving into this caliber.

To possibly further this theory, my Peterson had .013-.014 stretch and the Lapua had less than half that at .005-.006. The Lapua did not have heavy bolt lift but had a very very conservative load which was manufacturers starting load of 77gr. It was also 200+ fps slower than H1000.

MY BIG MYSTERY IS, then why did the Lapua still show faint ejector swipes at starting load with a slow fps. Maybe 30thou off lands is still too close? Maybe it has something to do with the can? Have not tried shooting without a can. Well I have but it was a while back. Basically I got this rifle, did very light break in loads (78gr of H1000) to break it in and went into OCW testing. Well I shelfed this whole rifle for over a year and am just now getting back into this rifle. That's why I cant remember what all fully transpired on my first round of OCW.

Also I love your stuff. Have 2 of your bags and used it to shoot these in the pics!
Click to expand...

I’ve put faint ejector marks on Lapua 308 brass with starting loads. 185 Juggs with Varget too close to the lands.

Just cause it’s Lapua doesn’t mean it’s bomb proof.
 
#45
supercorndogs said:
Flat primers, meh. Some primers cratered and some not, look the fuck out.

Your brass is telling you , you are making way too much pressure. At the range it was telling you, stop fucking shooting me and figure out why I am way over pressure. This is a 101 problem. You don't need help from a forum, you need to go back to the basics and start learning the very first things about reloading. I don't care what velocities others make and how much powder they use. Reloading is an individual process for each gun.

I am glad you didn't have a catastrophic failure, and that you came here to get scolded before you did. For future reference, when you see ejector swipes, extractor marks, and cratered primers it is past time to stop shooting that ammo.

I bet most of that brass will no longer hold a primer.
Click to expand...
Just a thought and I had similar issues back in the day rem 700 308, came to the understanding really bad barrel (chamber) . Rebarrel , with super match chamber. Poof! My problem solved. To many high production barrels, low QC.
 
#46
Bemoni said:
It happens when the pressure is getting higher than the dimensions on the shellcase are designed for ( like a boiler without safetyvalve ), then something has to move and give way.
And brass is by nature very easy to manipulate, just by mechanical force, so when the pressure is rising inside the case, this will expand to a certain degree and retract again, when the pressure goes down.
But, if the pressure is higher than the design allows, the case material may start moving, by the most convinient way and that's usually through a unsupported area, such as the the primer pocket or the rim, releasing most of the gas, from the combustion, somewhere it really hurts.
Sorry if there are some typos and grammars, i'm not use to write this in english, but i'm trying my best.
Click to expand...
Interesting
 
#47
Milo 2.5 said:
Cheap really, generate nice pics, more versatile with adaptation to phone or laptop
Click to expand...
Hmm ok haven’t seen the one on the rod yet. I’ll prob have to get it hehe.

Think it’s all figured out now. So combo of brass being too short, dirty bolt and distance to lands and I’m hoping in that order.

Shot some Lapua again today after cleaning the chamber and bolt, also sat bullet from .029 off to .033 off lands (because had luck at .033 off too) and no ejector holograms or extractor marks. No heavy bolt at all.

Circled groups are from before. Pointed out a few of the holograms that are hard to see. Shot the 10 non circled rounds today and no marks at all.


I have H1000 loads ready for the lapua brass but was too windy today to shoot them. That’ll happen Thursday
 
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