Pressure signs

[DonnyJ]

I look at flatted primers as ok.
But when the primer starts to crater around the firing pin strike, I stop!

Is there some other indication I should look for?
When you're working up a load, what do you look for in the way of pressure signs?
What indications are you looking for that'll make you say, ok that's it, no more powder!

Thx

 

[hdbiker1]

I don't rely on the primers too much, but look for ejector marks or heavy bolt lift.

 

[10 x]

Primers aren't very reliable way to go. They all have different cup hardness and flatten at different pressures. Soft cups flatten early while hard ones may have brass flow long before they do. Cratering also isn't reliable for same reasons as flattening along with firing pin shape and pin hole size. Way I found most reliable is measurimg case head expansion with a mic. Best done with new cases only. expansion also varies depending on manufacture of brass. Rem vs Lapua for example. Case web design also affects it. Experience and comparison with known pressure test loads is best.

 

[M-61]

I've had rifles that will crater primers with quite moderate loads. I really don't rely on the cratering of the primer as an indication of high pressure. Rather an indication of a poorer fit of the firing pin in the bolt. Bushing the bolt produces the end of the cratering. However any time you feel something is not SAFE my suggestion is to stop and go back over exactly what you loaded and what it may have done before.
Yes to the ejector marks and a big YES to the heavy bolt lift.

 

[10 x]

Ejector marks and heavy lift mean brass flow. Very very high pressure. Depending on chamber but even with a loose chamber well over 72000 psi.

 

[fgregorio]

In my opinion, you can detect high pressures also by checking for gas leakage between the primer and the primer pocket. Best to use a magnifying glass and good lighting. That is your first sign. A cratered primer for me is a last warning. Ejector marks for me it means that you are risking the gear and your health.

 

[bheadboy]

I don't look at the primer except possible gas leak from loose hole, toss it,

I measure the sized case at the pressure ring, fired case there, if the two are within .001 on small cases ie 222etc I do not worry, on 06 case head calibers I stop at .0015.

the 2nd tel-tail is hard bolt lift or bolt lift marks on the case face.

Bob

 

[Toolbreaker]

.....or bolt lift marks on the case face.

Bob

I consider the rub marks Bob is referring to as the first real indication of high pressure. It may or may not be excessive, but it's definitely up there. Far enough for me, anyways.

 

[calgarycanada]

If resized properly, I find ejector mark pretty reliable. If I see even faintest ejector mark I back off. I agree with above that if bolt lift is hard you better back the hell out(atleast a grain in 308 sized case) JMHO

 

[Lapua40X]

If resized properly, I find ejector mark pretty reliable. If I see even faintest ejector mark I back off. I agree with above that if bolt lift is hard you better back the hell out ...

Ditto ..............

 

[Tomekeuro85]

Do you gents use the same indicators on .223? I would imagine larger calibers would cause more significant pressure signs as it increases... but I'm not really sure so maybe someone knows better than I.

 

[CatShooter]

Do you gents use the same indicators on .223? I would imagine larger calibers would cause more significant pressure signs as it increases... but I'm not really sure so maybe someone knows better than I.

The signs are the same - the pressures of modern cartridges are ~~the same.

 

[mac86951]

Do you gents use the same indicators on .223? I would imagine larger calibers would cause more significant pressure signs as it increases... but I'm not really sure so maybe someone knows better than I.

The signs are the same - the pressures of modern cartridges are ~~the same.

True, but I'll add that I tend to see a more pronounced "near max" loading sign on my larger calibers. Not due to pressures generated, but due to the better controls for powder weight variation. IE 1% increase in a 308 is more grains than a 1% increase in .223, so don't forget to account for measurement variations.


-Mac

 

[243winxb]

 

[CatShooter]

Do you gents use the same indicators on .223? I would imagine larger calibers would cause more significant pressure signs as it increases... but I'm not really sure so maybe someone knows better than I.

The signs are the same - the pressures of modern cartridges are ~~the same.

True, but I'll add that I tend to see a more pronounced "near max" loading sign on my larger calibers. Not due to pressures generated, but due to the better controls for powder weight variation. IE 1% increase in a 308 is more grains than a 1% increase in .223, so don't forget to account for measurement variations.


-Mac

If you can't hold your loads closer than 1%, then you need to shoot factory.

 

[bigedp51]

Do you gents use the same indicators on .223? I would imagine larger calibers would cause more significant pressure signs as it increases... but I'm not really sure so maybe someone knows better than I.

The signs are the same - the pressures of modern cartridges are ~~the same.

CatShooter

On .223/5.56 cases (or any brand case) brass flow into the ejector is governed by brass hardness, meaning with a Remington .223 case you will get ejector marks before you would on a Lake City case that has higher standards for hardness in the base of the case. A few months back you posted rockwell brass hardness for .223/5.56 cases in which Lake City and Lapua being the hardest and Remington cases being the softest.

Botton line, your case pressure signs depend on brass hardness and the chamber pressures will not be the same with all cases. As another example my Savage .223 has a "LONGER" throat than either of my AR15 rifles and its max loading is higher before brass flows into the ejector.

A chain is only as strong as its weakest link.

Signed
Your non-case greasing buddy Bigedp51.

 

[CatShooter]

Do you gents use the same indicators on .223? I would imagine larger calibers would cause more significant pressure signs as it increases... but I'm not really sure so maybe someone knows better than I.

The signs are the same - the pressures of modern cartridges are ~~the same.

CatShooter

On .223/5.56 cases (or any brand case) brass flow into the ejector is governed by brass hardness, meaning with a Remington .223 case you will get ejector marks before you would on a Lake City case that has higher standards for hardness in the base of the case. A few months back you posted rockwell brass hardness for .223/5.56 cases in which Lake City and Lapua being the hardest and Remington cases being the softest.

Botton line, your case pressure signs depend on brass hardness and the chamber pressures will not be the same with all cases. As another example my Savage .223 has a "LONGER" throat than either of my AR15 rifles and its max loading is higher before brass flows into the ejector.

A chain is only as strong as its weakest link.

Signed
Your non-case greasing buddy Bigedp51.

BigEd... badd puppy!!

You took my comments out of context - the question was related to the size of the case, not hardness - if you are going to change unspoken of variables, then you make it necessary for respondents to qualify everything:

Id Est - the signs are the same:

IF the case brass is of equal hardness;
If you have similar throats;
IF the leade angle is the same;
IF the bullet jacket hardness is the same;
IF the core hardness is the same;
IF the powder is from the same lot;
IF your girl friend pulled the trigger with the same effort;
IF the rifle was held in the same position;
IF the rifle was shot in the same geographical area;
If the effects of gravity are the same;
IF your dog got a clean bill of health from the vet and can go hunting with you;
And IF your favorite guppy isn't in heat and cross breeding with that God damned horny gold fish!


Then it is the same

 

[bigedp51]

BigEd... badd puppy!!

You took my comments out of context - the question was related to the size of the case, not hardness

CatShooter

I didn't take your comments out of context or criticize your comments, I just wanted the people reading this to take anything they read here as gospel. The OP asked about pressure signs and primers and many said you can't trust just reading the primers. And I added you can't trust your fired cases either because all brass isn't the same hardness.

Meaning a load you work up with Lake City or Lapua brass will look OK "BUT" if you switch to Federal or Remington brass you will have signs of excess pressure.

The factory loaded cases below in my scrap brass bucket have over sized primer pockets after the first firing. (never reloaded) This doesn't mean the load was over pressure, it simply means the manufacture made the brass too soft.

Below is a workup load showing increasing pressure with primers and how people should learn to read their primers.

Below are signs of excess pressure with .223/5.56 brass and what reloaders should look for on the base of the case.

So again Catshoter my two dyslexic typing fingers failed to get my point across, I was hoping you would post your Rockwell hardness figures you posted before and educate all the people reading this about "ALL" the variables when looking for pressure signs. (especially the novices new to reloading)

Meaning you could be well below actual max pressure but soft primers and brass would make you think you are.

P.S. I would never think I could teach you anything CatShooter..............................
the only person I know who could teach you anything would be fguffy.

NOTE: Even your posts are starting to read like fguffys.................... :

IF the rifle was shot in the same geographical area;
If the effects of gravity are the same;
IF your dog got a clean bill of health from the vet and can go hunting with you;
And IF your favorite guppy isn't in heat and breading with that God damned horny gold fish!

Bazinga

I mean, not everyone can be a Einstein in this forum when we have so many Yo-yos with meaningless theories.

 

[CatShooter]

Good morning Edwardus Maximus.

You are forcing me to be serious at 6:03 AM and I had promised myself that I wouldn't be serious all day

Pressure in guns is a complex thing - I read guys on here that say:

"My load is 71.3486 grains of "MagnumBlaster powder, with a 138.75 gr AirSlipper bullet and I am running it at 61,428 PSI..."

Gasp!!

I own and run a Scottish digital pressure rig, and I used to run a Copper Crusher Bond Universal receiver ( ) for one of my clients - and I have always figured if I was +/- 5,000-psia, I was having a great day... so how does the above Mr. Dufus, get his pressures down to XX,428 psi... down to ONE DIGIT????

He DOESN'T!! It is impossible. He is naively believing one of those silly windows in his "Quick Load" program. It's called, "If you can't blind them with brilliance, then baffle them with bullshit!"

Assuming that someone is using a fairly modern rifle w/TWO lugs made of steel, in a receiver of modern steel (that leaves all you guys with Savage 340's out, so you can stop reading)...

... the only pressures you need to be concerned with are the ones that generate signs/problems in YOUR rifle, with YOUR components - the numbers are meaningless.

The three weak areas in the modern rifle are the case head, the primer, and the firing pin spring.

If your primers are not extruding into the pin hole in the bolt, and the head is not deforming, you are Okie Dokie.

And that is exactly what we all do when we work up loads - and the reason that we drop 10% and work up until we see whatever pressure signs we trust, instead of all using the same load, is because there are eleventy hundred variables.

It took me 45 minutes to find the case hardness post you asked for.

So, Edwardus Maximus, this post is for you!

P.S...

"the only person I know who could teach you anything would be fguffy.

NOTE: Even your posts are starting to read like fguffys.................... :
"

I keep sending fguffey ballistic and loading questions, but he keeps correcting my syntax and grammar and spwelying and won't answer my questions

P.S.S... You have the bestest pictures on the internet - I know, cuz I stole them all



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Is the hardness in brass vary between manufactures?
If so who's are harder and softer?
Thanks

Most guys guess... but here are some real numbers I did in the spring of 2014.

Pardon the mess - it always looks like this in the spring and this spring is worse, cuz Martha Stewart's maid couldn't make it this month, and the woodchucks are calling...

My $2,500 Ames Hardness Gauge -- it is FAA certified and approved for testing aircraft engine parts (you cannot get a better tool than that!)

I measured four cases which were picked at random.

LC 2008 5.56mm
Lapua 223 Match
Winchester 223
Remington (R-P) 223


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Lake City 2008

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Lapua 223 Match

[

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Winchester 223

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Remington (R-P)

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The actual Hardness measurements were (.062"x100kg, Rockwell "B")

LC 2008 = 96

Lapua 223 Match = 86

Norma 30-06 - 76 (added n Dec -'14)

Winchester 223 = 69

Norma .220 Swift = 64 (added in Dec '14)

Remington "R-P" = 49

For all you guys that have been saying that Winchester cases were tougher than Remington... you are vindicated, they are a lot tougher!... 40% tougher

For all you guys that think Lake City is surplus junk, nothing could be further from the truth. It is some of the most bestest brass made (it is paid for by the tax payer), so enjoy it!!!

LC and Lapua are the "The pick of the litter"!


(Ain't modern telephones wunnerful fer pictures ??)

 

[Joe Salt]

Boy they got your shorts in a knot this Morning, Chill Man Chill. They will figure what pressure is like I did back in the 60's, when my 22-250 us to spit back in my face. Even though I was doing what the loading book said.

joe salt