Peterson Virgin Brass Pressure Signs

FNG1001 · Feb 24, 2023

New to Peterson 6.5 Creedmoor SRP brass. Picked up a couple boxes and thought i'd fireform it first with some Hornady 140 gr i have available.

I shot 10 and started seeing what looked like pressure signs, though I could be wrong (first time trying Peterson brass). I stopped after these initial firings just to be sure, and inspect.

Shoulders grew 0.004
Gordon Reloading Tool warns of pressure >40 grains.

My question is: has anyone experienced similar results using Peterson brass, or with virgin brass? I plan on dropping the charge on the remaining cases and seeing how they do.

Details:
Brass: (0x fired - Virgin) Peterson 6.5 CM SRP
Powder: 38 gr H4350
Bullet: 140 ELD-M Hornady
Primer: Federal 205
COAL: 2.838
CBTO: 2.203
Case length average: 1.912
Peterson reported average case volume (H2O): 50.6 grains

Brass Prep:
Tumbled
FL resized to fix necks (no change to shoulder)
Chamfered & deburred

nn8734 · Feb 24, 2023

Any sticky bolt lifts? What’s the diameter of the case web now vs before firing? More than .001 expansion is a sign of overpressure but I don’t see anything alarming on your case heads….how did those rounds print? shoulders growing .004 is no big deal. Just set your fl sizing die so it bumps them back .002

Cascade Hemi · Feb 24, 2023

Low pressure

straightshooter1 · Feb 24, 2023

FNG1001 said:
New to Peterson 6.5 Creedmoor SRP brass. Picked up a couple boxes and thought i'd fireform it first with some Hornady 140 gr i have available.

I shot 10 and started seeing what looked like pressure signs, though I could be wrong (first time trying Peterson brass). I stopped after these initial firings just to be sure, and inspect.

Shoulders grew 0.004
Gordon Reloading Tool warns of pressure >40 grains.

My question is: has anyone experienced similar results using Peterson brass, or with virgin brass? I plan on dropping the charge on the remaining cases and seeing how they do.

Details:
Brass: (0x fired - Virgin) Peterson 6.5 CM SRP
Powder: 38 gr H4350
Bullet: 140 ELD-M Hornady
Primer: Federal 205
COAL: 2.838
CBTO: 2.203
Case length average: 1.912
Peterson reported average case volume (H2O): 50.6 grains

Brass Prep:
Tumbled
Chamfered & deburred

That's good data to help diagnose what might be going one, except velocity with barrel length would be really helpful too.

That 38 grs of H4350 shouldn't be giving you anywhere near any pressure signs, though the pictures of the head suggest your close. But that might be because you need a little more powder since you're loading a bit long???

ACard · Feb 24, 2023

I have loaded Peterson 6.5CM for several years now. After adjusting the charge for the slightly less case capacity I landed on a charge of 41.6 gns of H4350 with a 140 eldm on top and have never seen pressure from that load. That said had a friend go through the same process and have similar reaults as you, but it was not pressure. He shoots an RPR and ended up that his presumed cratering was from a sloppy bolt face and firing pin fitment. He had it busched and all of the supposed cratering went away. YMMV

b6graham · Feb 24, 2023

what platform are these bring fired from? being its SRP brass

38gr is a pretty low charge

JOE62 · Feb 24, 2023

Get some CCI 450’s SRMagnum primers. The cups are thicker. Or. Go back to LRP brass or get the bolt bushed. Had one doing the same thing. Swapped back to LRP brass and primers and good to go.

Cascade Hemi · Feb 24, 2023

JOE62 said:
Get some CCI 450’s SRMagnum primers. The cups are thicker. Or. Go back to LRP brass or get the bolt bushed. Had one doing the same thing. Swapped back to LRP brass and primers and good to go.

Bushing the bolt and switching to 450's won't fix the ejector swipes.

@FNG1001 bump 2.00 grains up and reshoot.

spife7980 · Feb 24, 2023

Seems about right for peterson being the junk it is.
Should be harder on the second firing and I doubt you see the issue then.

M4orturnate · Feb 24, 2023

I run between 41.2 and 41.9g h 4350 with peterson brass and 140-147g bullets.

JOE62 · Feb 24, 2023

.004 from the cases being that much short on the first firing is what is causing the ejector marks. When the case head accelerates backwards after being driven forward by the firing pin. Make the cases a crush fit on the first firing will stop the ejector marks and possibly the primer cratering. Expand the necks to 7mm then run them in your sizing die and create a false shoulder for the first firing.

LR1845 · Feb 25, 2023

spife7980 said:
Seems about right for peterson being the junk it is.
Should be harder on the second firing and I doubt you see the issue then.

Spife do you really think Peterson is junk? Honest question.

spife7980 · Feb 25, 2023

LR1845 said:
Spife do you really think Peterson is junk? Honest question.

I think it’s definitely not in the top

JOE62 · Feb 25, 2023

Screw your sizing die out so it doesn’t push the shoulder back and try to chamber it. When it sizes the body it will push the shoulder forward. Then screw the die down until it chambers with a little resistance. That will be your cartridge base to shoulder datum length. Check that against your virgin brass and that’s the difference in length. Your virgin brass will not be completely fire formed on the first firing. Especially not at 38 grns unless you are jamming your bullets.

FNG1001 · Feb 25, 2023

Thanks for everyone's thoughts and experiences on this! I'll be shooting the rest today (slowly). Will update once i have more data. Also cleaned the bore and bolt to start from a clean slate. To include taking the ejector out and giving everything a cleaning.

nn8734 said:
Any sticky bolt lifts? What’s the diameter of the case web now vs before firing? More than .001 expansion is a sign of overpressure but I don’t see anything alarming on your case heads….how did those rounds print? shoulders growing .004 is no big deal. Just set your fl sizing die so it bumps them back .002

I cant recall any sticky bolt. Biggest concern I had was when looking at the case heads and seeing the ejector marks, but also from these old eyes, the primers looked slightly cratered+flattened.
Forgot to mention in the brass prep that after tumbling, and before chamfer/deburr, I ran all the brass through a FL resizer just to get the necks concentric (edited now). No change in shoulder in doing this.

Thank you for suggesting to measure the case web. Unfortunately, I already ran them through a FL sizing die. For what it's worth, even through already FL resized, looks like the case web grew by 0.002 consistently across those fired (new out of box = 0.4675)

Cascade Hemi said:
Bushing the bolt and switching to 450's won't fix the ejector swipes.

@FNG1001 bump 2.00 grains up and reshoot.

Will be working up to it slowly today. Will update once i have more data.

spife7980 said:
Seems about right for peterson being the junk it is.
Should be harder on the second firing and I doubt you see the issue then.

I was thinking it might be due to it being it's first firing, but i have never had these marks show up with similar loads on Hornady or Norma brass.

JOE62 said:
.004 from the cases being that much short on the first firing is what is causing the ejector marks. When the case head accelerates backwards after being driven forward by the firing pin. Make the cases a crush fit on the first firing will stop the ejector marks and possibly the primer cratering. Expand the necks to 7mm then run them in your sizing die and create a false shoulder for the first firing.

This was my thought too, that the 0.004 might be a bit much of a gap in the chamber. I'll be shooting the rest today (slowly). Will update once i have more data.

918v · Feb 26, 2023

What is your neck clearance?

supercorndogs · Feb 26, 2023

.004 growth on the first firing is not that much. I wouldn't expect it to leave ejector marks.

JOE62 · Feb 26, 2023

The.004 was after firing if I read it right. The cases grew .004 in length to the shoulder on the first firing shooting 38 grns of H4350. The cases did not fully fire form to chamber dimensions on the first firing with that load. Cases are likely.006-.008. shorter than the chamber when unfired. The OP could try neck sizing only the once fired brass and then he would have a closer representation of his actual chamber length. Also a good call on the neck clearance.

Rocketmandb · Feb 26, 2023

spife7980 said:
I think it’s definitely not in the top

Glad I'm not the only one who feels this way. When 6CM was a new thing, and all you could get was Hornady, I was happy when Peterson came out with their SRP 6CM Brass. The first time I shot it, I got the same sport of pressure signs the OP is showing (at similarly low loads) and had issues getting the primers out. Not too long after, Lapua came out with their 6 and 6.5 CM brass and all things were right with the world.

The only good thing about my 6CM Peterson experience was that I broke so many primer pins on the brass that it turned me toward getting a Harvey Deprimer.

That said, Peterson is my only choice for my 37XC, and it's holding up pretty well.

Cascade Hemi · Feb 28, 2023

I think I have at least 2k pieces of Peterson 6CM and 6.5CM brass. I have had less defective Peterson cases in all 2k pieces than the last single 100pc box of Lapua brass.

FNG1001 · Mar 1, 2023

Shot the remaining 50 rds. I got the same plunger marks on all case heads, however, no other signs of pressure and the bolt throw/lift was normal.

I went ahead and reloaded another set of 50: 10 strings of 5 rounds from 39.0 - 40.8 grains of H4350.
My brass prep was the normal:

tumble
anneal (2 sacrificial Peterson brass gave me 146 and 147 AZTEC code on the AMP),
FL resize (0.002),
trim to size (1.910),
powder+seat bullet (COAL = 2.8380, CBTO = 2.2170).

Looking at the heads, same marks, but operating the bolt felt smooth. A close up of the case heads' (max charge 40.8 grains) primers doesn't show any flattening. I'm starting to think the ejector marks aren't a concern (please correct if you think otherwise), and could just be a combination of my bolt with this brass.

Average speed of x1 fired: 2608 - 2739 fps (39.0 - 40.8 grains H4350)

I still have a couple of unfired boxes of this brass that i can compare measurements to with x1 and x2 fired.

supercorndogs · Mar 1, 2023

JOE62 said:
The.004 was after firing if I read it right. The cases grew .004 in length to the shoulder on the first firing shooting 38 grns of H4350. The cases did not fully fire form to chamber dimensions on the first firing with that load. Cases are likely.006-.008. shorter than the chamber when unfired. The OP could try neck sizing only the once fired brass and then he would have a closer representation of his actual chamber length. Also a good call on the neck clearance.

Where did you read that? .006-.008 seems like pure speculation, also .006-.008 proabay isn't going to produce ejectors marks either. The cases I have seen it on have been belted mags growing in the .015+ area anyway.

LR1845 · Mar 1, 2023

Cascade Hemi said:
I think I have at least 2k pieces of Peterson 6CM and 6.5CM brass. I have had less defective Peterson cases in all 2k pieces than the last single 100pc box of Lapua brass.

This is why I quit using lapua brass when I reloaded which has been over 2yrs ago...1 box of Lapua had 20 pieces that the necks looked like someone stepped on them.

supercorndogs · Mar 1, 2023

Its pretty normal for brass to get the necks dinged up in shipping. Run a mandrel or expander ball through them and carry on.

918v · Mar 1, 2023

FNG1001 said:
Shot the remaining 50 rds. I got the same plunger marks on all case heads, however, no other signs of pressure and the bolt throw/lift was normal.

I went ahead and reloaded another set of 50: 10 strings of 5 rounds from 39.0 - 40.8 grains of H4350.
My brass prep was the normal:

tumble

anneal (2 sacrificial Peterson brass gave me 146 and 147 AZTEC code on the AMP),

FL resize (0.002),

trim to size (1.910),

powder+seat bullet (COAL = 2.8380, CBTO = 2.2170).

Looking at the heads, same marks, but operating the bolt felt smooth. A close up of the case heads' (max charge 40.8 grains) primers doesn't show any flattening. I'm starting to think the ejector marks aren't a concern (please correct if you think otherwise), and could just be a combination of my bolt with this brass.

Average speed of x1 fired: 2608 - 2739 fps (39.0 - 40.8 grains H4350)

I still have a couple of unfired boxes of this brass that i can compare measurements to with x1 and x2 fired.

What is your neck clearance?

Cascade Hemi · Mar 1, 2023

supercorndogs said:
Its pretty normal for brass to get the necks dinged up in shipping. Run a mandrel or expander ball through them and carry on.

Please, Lapua is known to ship folded shoulders.

LR1845 · Mar 1, 2023

supercorndogs said:
Its pretty normal for brass to get the necks dinged up in shipping. Run a mandrel or expander ball through them and carry on.

I get it but these were far from just dings.

DellaDog · Mar 1, 2023

I dunno about Peterson = junk.

I have 20 firings on the same Peterson 6.5 brass loaded at 41.5 gr 4350 through 3 barrels.

I have not lost a single piece to pressure or loose pockets.

supercorndogs · Mar 1, 2023

But Lapua is trash now.

LR1845 · Mar 1, 2023

supercorndogs said:
But Lapua is trash now.

No not trash at all but its sure not the gold standard that it use to be back in the day.

supercorndogs · Mar 1, 2023

Cascade Hemi said:
Please, Lapua is known to ship folded shoulders.

Support your ambiguous claim. Everyone is known to have product defects. Brass getting bashed by shippers is not a manufacturer defect.

supercorndogs · Mar 1, 2023

LR1845 said:
No not trash at all but its sure not the gold standard that it use to be back in the day.

Please qualify, "back in the day." And how it has changed since "back in the day." Better yet, maybe you should start your own thread and do so.

Cascade Hemi · Mar 1, 2023

LR1845 said:
I get it but these were far from just dings.

How many of these should come in the box?

Cascade Hemi · Mar 1, 2023

supercorndogs said:
Support your ambiguous claim. Everyone is known to have product defects. Brass getting bashed by shippers is not a manufacturer defect.

I don't generally make claims I can't support, see above. I've posted the picture here before and got more than a few me too's.

LR1845 · Mar 1, 2023

supercorndogs said:
Please qualify, "back in the day." And how it has changed since "back in the day." Better yet, maybe you should start your own thread and do so.

Butt hurt because someone said lapua brass is not the gold standard anymore...funny!!

15 years ago when I bought a box lapua brass I did not get crushed necks or folds in the shoulders so you tell me how it has changed.

918v · Mar 1, 2023

LR1845 said:
Butt hurt because someone said lapua brass is not the gold standard anymore...funny!!

15 years ago when I bought a box lapua brass I did not get crushed necks or folds in the shoulders so you tell me how it has changed.

Demand

LR1845 · Mar 1, 2023

918v said:
Demand

Agree 100%!!

Cascade Hemi · Mar 1, 2023

Some people are awful charitable regarding defects with one company while holding other companies to a zero tolerance standard.

OP may have gotten soft brass, switch to something else and see what happens. I doubt .004" is enough bolt thrust to cause the issue but you can check it by jamming the lands.

Haney · Mar 1, 2023

DellaDog said:
I dunno about Peterson = junk.

I have 20 firings on the same Peterson 6.5 brass loaded at 41.5 gr 4350 through 3 barrels.

I have not lost a single piece to pressure or loose pockets.

Don't believe a word he writes .He loves to talk bullshit , probably never touched a piece of Peterson brass in his life . As you will notice he backed down from "Junk" to this when called out . Like most people here in the reloading department , just screaming for attention .

spife7980 · Mar 1, 2023

Haney said:
Don't believe a word he writes .He loves to talk bullshit , probably never touched a piece of Peterson brass in his life . As you will notice he backed down from "Junk" to this when called out . Like most people here in the reloading department , just screaming for attention . View attachment 8086447

Rich coming from the guy who asked why gun ranges dont also grow weed.
And I backed down because its obviously not s&b bad. But I sure wouldnt call it good.

Its junk because they cant hold primer pocket depths to within a thousandth and they also cant control neck thickness to less than a thousandth.
Nevermind the fact that under 40 gr in a creed leaves my pockets loose at only five firings.

At least they have learned to center up the flash holes now.

supercorndogs · Mar 1, 2023

Cascade Hemi said:
I don't generally make claims I can't support, see above. I've posted the picture here before and got more than a few me too's.

That is one folded neck. your statement made it sound like its a matter of business practice. What you could have said to avoid confusion would have been, "I got a piece with a folded neck once."

Granted, how i am supposed to know that is a piece of Lapau brass?

LR1845 said:
Butt hurt because someone said lapua brass is not the gold standard anymore...funny!!

15 years ago when I bought a box lapua brass I did not get crushed necks or folds in the shoulders so you tell me how it has changed.

No, I asked for you to qualify your statements, because it lacked any basic information, and you just made a dude-bro statement.

You still have not.

The worst Lapua brass I have had was a couple hundred pieces of Lapua Gold Box 243, and that was also "back in the day."

Of course they are not visually inspecting every peice they make and some bad pieces will get through. No body is, and everybody has some bad ones get through. I can say that is the first fold I have seen in Lapau brass. I have seen them in most other brands.

Most products have taken a hit in quality over the last 3 years. I haven't bought much during these trying times.

supercorndogs · Mar 1, 2023

Cascade Hemi said:
Some people are awful charitable regarding defects with one company while holding other companies to a zero tolerance standard.

OP may have gotten soft brass, switch to something else and see what happens. I doubt .004" is enough bolt thrust to cause the issue but you can check it by jamming the lands.

I didn't say anything about any other brand chief...And I didn't see Spife say anything about Lapau.

LR1845 · Mar 1, 2023

Cascade Hemi said:
How many of these should come in the box?

I'm going to go with zero.

LR1845 · Mar 1, 2023

supercorndogs said:
That is one folded neck. your statement made it sound like its a matter of business practice. What you could have said to avoid confusion would have been, "I got a piece with a folded neck once."

Granted, how i am supposed to know that is a piece of Lapau brass?

No, I asked for you to qualify your statements, because it lacked any basic information, and you just made a dude-bro statement.

You still have not.

The worst Lapua brass I have had was a couple hundred pieces of Lapua Gold Box 243, and that was also "back in the day."

Of course they are not visually inspecting every peice they make and some bad pieces will get through. No body is, and everybody has some bad ones get through. I can say that is the first fold I have seen in Lapau brass. I have seen them in most other brands.

Most products have taken a hit in quality over the last 3 years. I haven't bought much during these trying times.

So I'm going to say 2005 or 2006 was the last time I bought lapua brass(back in the day)I had 20 pieces out of 1 box that the necks were crushed like they'd stepped on not just minor dings...if i remember correctly(you know the bro-dude thing)had 30 case like that out of 300pcs(3 boxes)and 10 other pieces with that same fold in the shoulder like Cascade Hemi posted.

And I agree just about everything has taken a hit in quality but prices have done nothing but go up...part of the reason I stopped reloading and just buy factory ammo.

supercorndogs · Mar 1, 2023

LR1845 said:
I'm going to go with zero.

Yes zero, but the only way to achieve it is individual QC, and you wont even pay Lapua prices now, so...

LR1845 · Mar 1, 2023

supercorndogs said:
Yes zero, but the only way to achieve it is individual QC, and you wont even pay Lapua prices now, so...

Agree and point taken.

Danrobberg · Mar 1, 2023

My alpha brass that’s shipped in containers that prevents them from smashing together and crushing necks seem to arrive in near perfect condition.

dmuffman80 · Mar 1, 2023

Check your ejector spring. It is probably too long. Consider removing three coils and try again.

FNG1001 · Mar 2, 2023

@918v
0.2910 after FL resize and no bullet.
0.2925 with bullet seated

Bullet is a Hornady 140 ELD-M measuring 0.2635 average.

Measurements taken from a Mitutoyo CD6 ASX.

918v · Mar 2, 2023

FNG1001 said:
@918v
0.2910 after FL resize and no bullet.
0.2925 with bullet seated

Bullet is a Hornady 140 ELD-M measuring 0.2635 average.

Measurements taken from a Mitutoyo CD6 ASX.

I meant fired case neck diameter vs loaded neck diameter.

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