The truth about "pressure signs"

[.38 Special]

Mods, close this, please. Apparently I do need to modify my posting style, as it seems to attract a certain type of *ahem* unproductive member.

 

[Gryffydd]

I've already responded in a productive manner to this thread

 

[Vern Humphrey]

Between you and ranger, I'm getting an earful of "You're making personal attacks" along with "You're a big doodoo head",

I missed the post where someone called you "a big doodoo head." Can you give me the post number?

 

[ranger335v]

"Between you and ranger, I'm getting an earful of "You're making personal attacks...", etc.

Vern, how 'bout his "... getting an earful of "You're making personal attacks"?

I just did a really quick review and saw no such comment, from anyone. Maybe it's a result of us non-thinking "unproductive posters"!
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The truth about "pressure signs" So I'm already in hot water over on the milsurp thread, so I might as well keep digging!"

It's kinda amusing when you stand back a little and look at it all! Guess .38 LIKES digging deeper holes and having them fall in on him!
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38, just to help, not only is there an actual correct definition of blown primers, there is a proper definition of "pierced" primers too. It's correctly applied to those with holes pushed out of the primer's rim. Those primers with holes punched out by the firing pin are properly said to be "blanked". Frequent word misuse doesn't really change the meanings, it simply shows a lack in the speakers perceived knowledge.

It's up to us to be able to recognise who really understands what he's saying. Those, as with many other terms, aren't often major issues. But frequent misuse does blur the proper terms & definitions and causes confusion; "Does the speaker mean what he's saying, or does he mean what he might be trying to say?"

It's better if we use correct terms and keep our language straight, otherwise none of us can ever be sure we actually got the intended message...?

 

[Wildfire]

My 2 Cents .

Hey There;
Not here to put down anyone..
PSI talks have gone on and on and usually end in very strong disagreements.
#1 this should be taken in to consideration anytime the subject gets around to PSI.
Even the factory ammo is not always right for every gun. We all have certain guns that we "feel" can take it and so we play ... Sometimes to the extreme.
I have and paid the price. Anyone that has been loading for any real length of time has fooled around with PSI . Some get lucky and some don't.

We rarely here about the ones that don't. I have seen most of the post here and must say {many } have valid points. But we also all know there is a limit.
It was already said, Some will push the speed limit and live to tell about it.
But then , he also knows that sooner or later something could go wrong.

Blown up guns can get ugly fast. Along with faces , hands ect.

But still some will speed...

I have learned that there will always be a faster gun and a faster horse.

As I said I mean no dis to anyone here. You guys know what you know and what we don't know will likely always remain some sort of mistery.

But I do enjoy watching ... Yes I have my own experiments and beliefs on the PSI issue. Maybe we should all take deep breath and come at this with clear heads.

United we stand / divided we fall.

 

[Robert Wilson]

I would rather not get drawn into the uglier aspects of the discussion, but there is one question I think interesting: why do Americans have such a peculiar desire to get the last bit of velocity from every rifle? It's not as though 100 feet per second make any meaningful difference in trajectory or terminal impact!

 

[falldowngoboom]

The thing is most people like to push things at least a little. Highway speed limits are a good analog for handloading. They're based on a combination of what is an acceptable speed for most people to travel given safety concerns and what is fast enough for people to get from point A to B. And yet this is meant to suffice for people with different agendas, driving different cars, with a great variation on reflexes and driving ability.

I think it's in our nature to at least desire to get away with a little more than we "should." Just like speeding on the highway, going over published load data increases risk imcrementally if not exponentially. Moreover, we ARE dealing with mechanical devices designed to contain pressure. Firing "safe" loads in an old (or poorly maintained) gun can be just as dangerous as going under the speed limit in an old car. An accident can still be very, very bad.

I doubt if my opinion here will change much about how some people choose to post, but I've found the most persuasive arguments tend to be ones that state facts, highlight that opinions are just that, and disparage only through statement of fact or logic. If your goal is truly to inform and help others and not to stand up on a soapbox, then IMO, that approach tends to be the most effective.

People can sense the difference between someone trying to offer their experience and someone who says things, accurate or not, so others will listen to them. In my experience, people tend to listen to the former and tune out the latter.

 

[Vern Humphrey]

Vern, how 'bout his "... getting an earful of "You're making personal attacks"?

I just did a really quick review and saw no such comment, from anyone. Maybe it's a result of us non-thinking "unproductive posters"!

Some people read what's on the screen, others read what they want to see.

 

[.38 Special]

Nothing better to do than drag up a dying thread and spread some more of your special kind of manure, eh Vern?

Everyone needs a hobby, I guess!

 

[Tim the student]

Vern said:

Some people read what's on the screen, others read what they want to see.

38 said:

Nothing better to do than drag up a dying thread and spread some more of your special kind of manure, eh Vern?

Everyone needs a hobby, I guess!

I say (ok, not me - Johnny Tyler from Tombstone - but it seems to be appropriate)

Christ almighty, it's like I'm sittin' here playing cards with my brother's kids or somethin'… you nerve-wracking sons-of-#^%^$es

Please, gents, kids, my neices, whatever, leave it alone if it serves no purpose. The lack of things like this is why I like THR.

 

[Walkalong]

I thought this one had died. Guess it's time for more popcorn.



Lights, action.......

 

[ljnowell]

I thought this one had died. Guess it's time for more popcorn.

I guess I should get my turn too then........

38 special, by your reasoning as long as a load falls under or at the published velocity then it is a safe load. I am going to disagree. There are variables such as powder lot variances, slight bullet weight differences, slight cartridge volume differences, etc. It would be very easy for someone shooting for the published velocity to get a new load of powder that is a little over pressure during its burn, a bullet that weights a grain more than it should, etc, and end up with an over pressure round. Hence the reason that you need to be able to recognize over pressure signs.

 

[Tony Sopranno]

From: Robert Wilson

I would rather not get drawn into the uglier aspects of the discussion, but there is one question I think interesting: why do Americans have such a peculiar desire to get the last bit of velocity from every rifle? It's not as though 100 feet per second make any meaningful difference in trajectory or terminal impact!

...Seems to me, all my guns like the middle of the published scales when it comes to making small holes in larger pieces of paper. My eyes (at my age) are my defining limit, and for me making nice groups/circles of about 1.250" radius is about as good as it gets.

I'm sure I might do better but it gets impracticable after a bit. Why feed more powder into those brass balloons for velocity, etc., when less often does the job far better? If it's about other ideas like knock-down and punch and ultimate velocity, you're always getting into pretty uncharted waters. At the end of the day, you only have one long circular series of argumentations.

I'd rather shoot circles into a piece of paper - and for the love of the sheer artistry, there is always golf, which is 75% shooter and 25% weapon of choice.

 

[Maj Dad]

Kind of Like Pornography

I know it when I see it. The first time I had to use a 2x4 to beat open the bolt on my new 308 Mauser in 1973, I knew I had exceeded the bounds. Primers flat, cratered, and cases (yes, cases - some idiots have to see it multiple times) looking like they came through a black hole. I learned volumes over that, and haven't had problems since (at least not on account of ignorance and stupidity). I had an epiphany of detail orientation, and it has at least kept me whole over the years.

 

[.38 Special]

38 special, by your reasoning as long as a load falls under or at the published velocity then it is a safe load. I am going to disagree. There are variables such as powder lot variances, slight bullet weight differences, slight cartridge volume differences, etc. It would be very easy for someone shooting for the published velocity to get a new load of powder that is a little over pressure during its burn, a bullet that weights a grain more than it should, etc, and end up with an over pressure round. Hence the reason that you need to be able to recognize over pressure signs.

If your new lot of powder is creating higher pressure than your previous lot, it will show up on the chronograph. "Slight" bullet weight differences -- as in a grain or so -- aren't going to make a significant pressure difference. Nor are slight case volume differences. Yes, using a case with significantly decreased volume will increase pressures, but again, it will show up your chronograph.

The bottom line remains that if you load up to published maximum velocities -- assuming you are using the same barrel length as the publisher -- it is very unlikely that you will exceed safe pressures.

Moreover, I have never claimed that there is no need to understand pressure signs. My claim is that grossly exceeding published loads in favor of home-grown load development based upon reading pressure signs is a dangerous mistake, because none of the traditional pressure signs are reliable. If you see one, you should stop and figure out why -- but the presence of pressure signs does not automatically mean excessive pressure, and the lack of them does not automatically equate to a safe load.

 

[ljnowell]

If your new lot of powder is creating higher pressure than your previous lot, it will show up on the chronograph. "Slight" bullet weight differences -- as in a grain or so -- aren't going to make a significant pressure difference. Nor are slight case volume differences. Yes, using a case with significantly decreased volume will increase pressures, but again, it will show up your chronograph.

The bottom line remains that if you load up to published maximum velocities -- assuming you are using the same barrel length as the publisher -- it is very unlikely that you will exceed safe pressures.

Moreover, I have never claimed that there is no need to understand pressure signs. My claim is that grossly exceeding published loads in favor of home-grown load development based upon reading pressure signs is a dangerous mistake, because none of the traditional pressure signs are reliable. If you see one, you should stop and figure out why -- but the presence of pressure signs does not automatically mean excessive pressure, and the lack of them does not automatically equate to a safe load.

Actually, your powder creating higher pressures doesnt always show up on a chronograph. I have seen safe loads that were not a problem and a load that blows up a gun only vary by 50fps. In many cases that is within the amount of fudge for the chrono or the bullet being loaded. Pressure does not have a linear relationship to velocity, as spikes will occur with many powders.

When i mentioned issues that will cause over pressure i was referring to the unfortunate incident of them all coinciding. The lesser case volume, a heavier bullet, powder variance, etc.

 

[Vern Humphrey]

Absolutely. For those who disagree, try this: work up a load for your 300 WM, using Bullseye powder. Start light, and keep increasing the charge until you reach 3100 fps with a 180 grain bullet.

Come back and tell us what happened.

 

[SSN Vet]

well I don't have a chrony and I don't have a pressure measuring rig....

so I'll use any and all of the indicators that I can get.... each weighed in my mind with the appropriate grain of salt. Ignoring any indicator is foolish in my mind.

Prudent and carefull re-loading techniques.... well reasearched load data.... quality, well preserved components.... understanding and paying attention to all of the indicators available to me at the range....

that's the course I'm steering

 

[.38 Special]

If the manuals showed any Bullseye loads in the .300 Magnum, Vern, your post would be quite illuminating. As it stands, though, it's just more Vern droppings.

 

[Walkalong]

Vern was just making a point. There are obviously no loads in manuals for Bullseye in for .300 Mag for the reason Vern alluded to, there would be dangerous pressure spikes way before you reached normal velocities.

"Vern droppings" That was cute though.

Folks wasting time arguing with someone who doesn't seem interested in reaching a conclusion, just needling folks to keep them going. SOS, different thread. See ya.