jeff-portnoy
December 31, 2012, 09:17 PM
Happy new year guys!
Please, explain to me high pressure signs for handguns !
Please, explain to me high pressure signs for handguns !
High pressure signs
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243winxb
December 31, 2012, 10:59 PM
http://www.shootersforum.com/handloading-procedures-practices/58763-pressure-signs.html For handguns i like numbers 1 3 8 11 12 17 18 19 22 27
kingmt
December 31, 2012, 11:21 PM
By the time you see high pressure signs in a handgun you are way over pressure.
918v
January 1, 2013, 12:09 AM
Not really. Using soft primers such as FC-100 or 150's emable you to approach high-pressure signs with caution.
Clark
January 1, 2013, 12:56 AM
When I started reloading ~13 years ago I tried to work up every bullet and every powder in 9mm until something bad happened. I kept the information on spread sheets.
I have now documented my overload work ups in 18 different handgun cartridges and 19 rifle cartridges.
As the years went by and I worked up to destruction with other handgun cartridges there were remarkable similarities.
As the professor in engineering ethics told us in ~1977, you don't learn much when the rocket blows up on the launch pad.
So I started learning some things not to do:
1) Don't work up loads until the brass yields in guns weaker than the brass.
2) Don't keep working up loads after the brass yields in guns stronger than the brass.
3) Don't do high pressure experiments on expensive old collector guns.
4) Don't shoot guns overloaded to the point where the the recoil will damage hand joints or nerves or cause a flinch.
5) Don't shoot semi auto pistols with loads way hotter than the recoil springs are absorbing. The slide will hammer the frame. Not good for the slide, the frame, or my hand. And the brass is hard to find when it ejects that far.
6) Don't document work ups with spread sheets. Do it like Ackley's books do it.
I have only blown ~ 12 handguns into pieces.
Put 12 handguns in plastic bags. Imagine there is nothing in the bags but blown up handguns. Heavy, aren't they? Imagine dropping those bags in the garbage. Imagine how much money you are out. Imagine how much trouble you are in if you blew them up at a public range. Imagine how hurt you and others could have been.
How to identify guns stronger than the brass?
That is a real trick, as there is no complete list in a book.
My father, the gun inventor, chief engineer with executive inside parking and a big office, showed me how to calculate the stress in the steel of a Handi Rifle 45/70. There was thick walled hoop stress, pins in double shear, and a breech face with different section modulus to calculate. I don't know the strength of the steel, but it is proportional to hardness, which can be measured. No matter what steel, it usually comes down to "Thick steel strong, thin steel weak".
38 Specials can have thin chamber walls.
So if I am working up a load with fast powder in a 38 Special, there may be no pressure sign in the brass before the cylinder splits and the top strap breaks.
So I don't do that any more. I think I have three of them in pieces in plastic bags.
In semi auto handguns some pressure signs I have seen:
1) Guppy belly case bulge
2) case bulge blow out hole.
3) Case head blows off, with many secondary failures, including parts exiting at lethal velocities.
4) Primer pierces
5) Primer falls out
6) barrel bulges
7) chamber splits, with many secondary failures, including parts exiting at lethal velocities.
8) slide hammers the frame until the gun will not fire
9) slide hammers the frame until the shooter flinches with a punching motion as he pulls the trigger.
10) slide hammers the ejector until it shears off.
In revolvers pressure signs I have seen:
1) cases stick and have to be pounded out of the cylinder
2) primer pierces
3) cylinder splits, with pieces exiting at lethal velocities.
4) cylinder splits and top strap breaks
5) frame bends
6) cylinder gets rotational looseness
7) top break latch stretches and gets loose
What does it all mean?
Don't overload guns unless you know what you are doing.
The first sign of trouble may be big trouble.
I have now documented my overload work ups in 18 different handgun cartridges and 19 rifle cartridges.
As the years went by and I worked up to destruction with other handgun cartridges there were remarkable similarities.
As the professor in engineering ethics told us in ~1977, you don't learn much when the rocket blows up on the launch pad.
So I started learning some things not to do:
1) Don't work up loads until the brass yields in guns weaker than the brass.
2) Don't keep working up loads after the brass yields in guns stronger than the brass.
3) Don't do high pressure experiments on expensive old collector guns.
4) Don't shoot guns overloaded to the point where the the recoil will damage hand joints or nerves or cause a flinch.
5) Don't shoot semi auto pistols with loads way hotter than the recoil springs are absorbing. The slide will hammer the frame. Not good for the slide, the frame, or my hand. And the brass is hard to find when it ejects that far.
6) Don't document work ups with spread sheets. Do it like Ackley's books do it.
I have only blown ~ 12 handguns into pieces.
Put 12 handguns in plastic bags. Imagine there is nothing in the bags but blown up handguns. Heavy, aren't they? Imagine dropping those bags in the garbage. Imagine how much money you are out. Imagine how much trouble you are in if you blew them up at a public range. Imagine how hurt you and others could have been.
How to identify guns stronger than the brass?
That is a real trick, as there is no complete list in a book.
My father, the gun inventor, chief engineer with executive inside parking and a big office, showed me how to calculate the stress in the steel of a Handi Rifle 45/70. There was thick walled hoop stress, pins in double shear, and a breech face with different section modulus to calculate. I don't know the strength of the steel, but it is proportional to hardness, which can be measured. No matter what steel, it usually comes down to "Thick steel strong, thin steel weak".
38 Specials can have thin chamber walls.
So if I am working up a load with fast powder in a 38 Special, there may be no pressure sign in the brass before the cylinder splits and the top strap breaks.
So I don't do that any more. I think I have three of them in pieces in plastic bags.
In semi auto handguns some pressure signs I have seen:
1) Guppy belly case bulge
2) case bulge blow out hole.
3) Case head blows off, with many secondary failures, including parts exiting at lethal velocities.
4) Primer pierces
5) Primer falls out
6) barrel bulges
7) chamber splits, with many secondary failures, including parts exiting at lethal velocities.
8) slide hammers the frame until the gun will not fire
9) slide hammers the frame until the shooter flinches with a punching motion as he pulls the trigger.
10) slide hammers the ejector until it shears off.
In revolvers pressure signs I have seen:
1) cases stick and have to be pounded out of the cylinder
2) primer pierces
3) cylinder splits, with pieces exiting at lethal velocities.
4) cylinder splits and top strap breaks
5) frame bends
6) cylinder gets rotational looseness
7) top break latch stretches and gets loose
What does it all mean?
Don't overload guns unless you know what you are doing.
The first sign of trouble may be big trouble.
gamestalker
January 1, 2013, 01:26 AM
About 99% of the primers I use sare CCI's and they have most always been very reliable in providing me with some viable indication of a pressure issue, high or low. But primers, regardless of what brand, are not always the most reliable source to decern pressures by.
But using primers for such requires intimately knowing the powder one is working with. For instance, I do a lot of loading with CCI 500's and 550's for several primary handgun cartridges such as 38 spcl, .357 mag, 9mm, and .40 S&W, and I load mid to upper level performing jacketed types. So when I see a flat primer, sharp outside edges on the primer with some cratering ridge surrounding the FP strike and it does not fill the pocket, it tells me I am within a safe, yet upper level or near max range for that load combination. But when the primer flows and fills most or all of the primer pocket along with a good cratering ridge, I know I have exceeded the safe operating pressure range for that load combination. And when I'm seeing primers backed out, evidense of gas leaking around the outside edges, an heavy cratering around the FP strike I know I'm operating below acceptable pressures for that load combination.
As for other evidense of pressure issues, the brass will also tella story and often a far more relaible one than a primer. Cartridges that extract easily yet look very sooty, usually indicate low pressures. Normal to low sooting and stiff extraction with revolvers, is a good indication pressures are high or above recomended pressures. If AL actions are kicking brass to extended distances and in rather unusual landing patterns, feeding ramp impressions or buldging that are easily visable on average supported chambers are pretty good indicators that pressures are well above recomended levels. Low pressures on aL actions would create cycling problems, sometimes excessive sooting, and severely backed out primers with poor deffinition or very rounded edges.
These signs are those which I experience with the primers, powders, and bullets I have learned to read with great reliablility. And depending on the paticular methods a reloader uses these identifying signs may not do justice. For instance, I do not ever crimp or bell my AL cases, and I use jacketed bullets exclusively along with slower burning powders which I have been working with for many years.
In conclusion, know your components and learn their reactive signs. And before moving onto a different method or component learn to read the current one's with some level of confidence allowable, as primers are only one indicator, and not always the most reliable one, but especially when changing brands.
GS
But using primers for such requires intimately knowing the powder one is working with. For instance, I do a lot of loading with CCI 500's and 550's for several primary handgun cartridges such as 38 spcl, .357 mag, 9mm, and .40 S&W, and I load mid to upper level performing jacketed types. So when I see a flat primer, sharp outside edges on the primer with some cratering ridge surrounding the FP strike and it does not fill the pocket, it tells me I am within a safe, yet upper level or near max range for that load combination. But when the primer flows and fills most or all of the primer pocket along with a good cratering ridge, I know I have exceeded the safe operating pressure range for that load combination. And when I'm seeing primers backed out, evidense of gas leaking around the outside edges, an heavy cratering around the FP strike I know I'm operating below acceptable pressures for that load combination.
As for other evidense of pressure issues, the brass will also tella story and often a far more relaible one than a primer. Cartridges that extract easily yet look very sooty, usually indicate low pressures. Normal to low sooting and stiff extraction with revolvers, is a good indication pressures are high or above recomended pressures. If AL actions are kicking brass to extended distances and in rather unusual landing patterns, feeding ramp impressions or buldging that are easily visable on average supported chambers are pretty good indicators that pressures are well above recomended levels. Low pressures on aL actions would create cycling problems, sometimes excessive sooting, and severely backed out primers with poor deffinition or very rounded edges.
These signs are those which I experience with the primers, powders, and bullets I have learned to read with great reliablility. And depending on the paticular methods a reloader uses these identifying signs may not do justice. For instance, I do not ever crimp or bell my AL cases, and I use jacketed bullets exclusively along with slower burning powders which I have been working with for many years.
In conclusion, know your components and learn their reactive signs. And before moving onto a different method or component learn to read the current one's with some level of confidence allowable, as primers are only one indicator, and not always the most reliable one, but especially when changing brands.
GS
918v
January 1, 2013, 01:30 AM
When FC-100 primers get this flat, you are above +P+ pressures. It's time to stop unless you want to impress Clark.
http://imageshack.us/a/img266/782/9mmhip1.jpg
The very bottom one is OK, though. It still has round edges. But the top left is really bad.
http://imageshack.us/a/img266/782/9mmhip1.jpg
The very bottom one is OK, though. It still has round edges. But the top left is really bad.
gamestalker
January 1, 2013, 01:30 AM
Oh, my information is intended to decern pressures before they pierce primers or blow case heads off, KB firearms, as those are obvious signs that are too late to be of much use during work ups.
GS
GS
steve4102
January 1, 2013, 08:47 AM
Copied this from a fellow reloader.
Think about this: Primers don't know what cartridge they're in.
A small pistol primer in 380auto and a small pistol primer in 38 Super.
The primer is too ignorant to know that it must flatten at 18000psi in the 380
but wait until 36000psi if loaded in a 38 Super. It just isn't smart enough.
Take that Winchester LP primer, good for both standard and magnum cartridges.
How does it know you seated it in a 45acp, or maybe a 44 Magnum?
Think about this: Primers don't know what cartridge they're in.
A small pistol primer in 380auto and a small pistol primer in 38 Super.
The primer is too ignorant to know that it must flatten at 18000psi in the 380
but wait until 36000psi if loaded in a 38 Super. It just isn't smart enough.
Take that Winchester LP primer, good for both standard and magnum cartridges.
How does it know you seated it in a 45acp, or maybe a 44 Magnum?
FROGO207
January 1, 2013, 09:01 AM
I find that if you start at the starting load and work up with a RECCOMENDED propellant there will be one or more spots that work/are accurate well BEFORE you have to worry about pressure problems. If not then that particular bullet/propellant combo was not a good one to begin with IMHO. I also feel that if there is no propellant specific load listed anywhere for a cartridge that might be a sign that it does not play well with a firearm so I avoid trying it. I am all about accuracy not about how fast bullets will go and how much recoil I can get. I outgrew that when I started having to work to buy my own stuff as a teenager.:cool: Also note that so far I have never blown up a firearm or had a squib (unless on purpose looking for a super light load) with my reloads.YMMV
jmr40
January 1, 2013, 09:24 AM
Buy a chronograph. It is the only way to reliably know that you are approaching excessive pressure. All of the conventional "signs" don't show up until you are already past the point of excessive.
If the loading manual says 1200 fps is a max load, then stop adding powder when you reach 1200 fps. You may be well below the amount of powder you manual says you need to reach 1200 fps, at least with that gun.
Sometimes primers flatten with perfectly safe loads. It is a poor indicator.
If the loading manual says 1200 fps is a max load, then stop adding powder when you reach 1200 fps. You may be well below the amount of powder you manual says you need to reach 1200 fps, at least with that gun.
Sometimes primers flatten with perfectly safe loads. It is a poor indicator.
wanderinwalker
January 1, 2013, 09:38 AM
I like steve4102's message and agree with it. I use the same Winchester or CCI primers in my .38 Special, 9mm and .357 loads. Depending on what combination it is that could be anywhere from 14k psi in a .38 Special load to 35k psi in a full-tilt 9mm or .357 load. Primer condition is only one part of what will tell you if you're still in the safe range or not.
I've seen factory .357 and .44 Magnum give primers quite similar to what is shown in 918v's photos. All extracted normally from the revolvers they were shot in. (In the case of the .44s those Winchester White Box 240grs were leaving my 6" 629 at 1300-fps by the chronograph.) So while they were definitely hot and I would certainly back off if my reloads were giving me that picture, it's a very subjective measure.
Another thing, RE: extraction from a revolver, again, it depends. A large frame revolver like a S&W 27 or a Ruger Blackhawk will drop cases out of the chambers that have to be smacked out of a smaller revolver such as a S&W 19. If you have sticky extraction in a .38 Special chamber you have done one of two things: you are WAY, WAY deep into dangerous territory or you haven't cleaned the chambers properly. A third possibility being your gun has rough chambers, in which case you'll probably always notice sticky extraction.
Observing fired case condition will tell you a lot. I've had tons of sooty cases from low-pressure loads. In my revolvers a .38 Special load operating normally will give you cases clean enough to reuse without tumbling, but factory UMC .357s give me dirty cases. My reloads with 2400 on the other hand are almost as clean as the .38 cases. Same in 9mm; a moderate charge of Unique gives me 1100-fps with a 115 and dirt, an almost full charge of Power Pistol with a 115 gives me 1250-fps and clean cases.
All of which is a long way of saying, so long as you stay within published loads and pay attention, you should be good. No, published data isn't infallible but it is at least a tested place to start.
I've seen factory .357 and .44 Magnum give primers quite similar to what is shown in 918v's photos. All extracted normally from the revolvers they were shot in. (In the case of the .44s those Winchester White Box 240grs were leaving my 6" 629 at 1300-fps by the chronograph.) So while they were definitely hot and I would certainly back off if my reloads were giving me that picture, it's a very subjective measure.
Another thing, RE: extraction from a revolver, again, it depends. A large frame revolver like a S&W 27 or a Ruger Blackhawk will drop cases out of the chambers that have to be smacked out of a smaller revolver such as a S&W 19. If you have sticky extraction in a .38 Special chamber you have done one of two things: you are WAY, WAY deep into dangerous territory or you haven't cleaned the chambers properly. A third possibility being your gun has rough chambers, in which case you'll probably always notice sticky extraction.
Observing fired case condition will tell you a lot. I've had tons of sooty cases from low-pressure loads. In my revolvers a .38 Special load operating normally will give you cases clean enough to reuse without tumbling, but factory UMC .357s give me dirty cases. My reloads with 2400 on the other hand are almost as clean as the .38 cases. Same in 9mm; a moderate charge of Unique gives me 1100-fps with a 115 and dirt, an almost full charge of Power Pistol with a 115 gives me 1250-fps and clean cases.
All of which is a long way of saying, so long as you stay within published loads and pay attention, you should be good. No, published data isn't infallible but it is at least a tested place to start.
HKGuns
January 1, 2013, 09:55 AM
Wow, I don't understand blowing up 12 pistols in only 13 years, that is just reckless, but I understand why you posted that little tidbit.
I also don't understand why in such a dangerous hobby you wouldn't stay within published data limits, most, if not all of which would be safe to shoot. Granted there may be variables unaccounted for, however in those instances you play it safe.
Can you provide a bit more insight into why you've learned spreadsheets are bad for documentation?
I also don't understand why in such a dangerous hobby you wouldn't stay within published data limits, most, if not all of which would be safe to shoot. Granted there may be variables unaccounted for, however in those instances you play it safe.
Can you provide a bit more insight into why you've learned spreadsheets are bad for documentation?
Grumulkin
January 1, 2013, 09:58 AM
By the time you see high pressure signs in a handgun you are way over pressure.
I believe that is true in the majority of instances but it isn't true in handguns designed to take pressures in the 55,000 to 65,000 psi range. These would include:
1. The Thompson/Center Encore.
2. Smith & Wesson's 460 and 500 S&W Magnums.
3. Various bolt action handguns.
By the way, I've never blown up any firearm and hope to keep that record for my remaining years.
I believe that is true in the majority of instances but it isn't true in handguns designed to take pressures in the 55,000 to 65,000 psi range. These would include:
1. The Thompson/Center Encore.
2. Smith & Wesson's 460 and 500 S&W Magnums.
3. Various bolt action handguns.
By the way, I've never blown up any firearm and hope to keep that record for my remaining years.
kingmt
January 1, 2013, 10:15 AM
I was trying a powder new to me. this stuff is so fast it makes Bullseye look slow. All I wanted was a soft recoil that would just operate the action. I used 115gn LRN working up .2gn at a time. I got to where it would cycle & was going up .2gn more for a safety margin but the primers feel out. I got some more brass thinking it was odd that all the brass had lose primers at saying a light load it had to already be bad. The once fired brass was loaded to the same as the last & after one firing the primer pockets were lose on them also. No other obvious signs until after I knew there was a problem & looked closer. I found the heads were ironed like or a little worse then the ones in 918's picture. I did run two more at .2gn less just to see if I missed something & found no warning.
918v
January 1, 2013, 10:41 AM
I've seen factory .357 and .44 Magnum give primers quite similar to what is shown in 918v's photos. All extracted normally from the revolvers they were shot in. (In the case of the .44s those Winchester White Box 240grs were leaving my 6" 629 at 1300-fps by the chronograph.) So while they were definitely hot and I would certainly back off if my reloads were giving me that picture, it's a very subjective measure.
In most revolvers cases begin to stick at approximately 45000 PSI so the fact they extracted normally doesn't mean anything.
In most revolvers cases begin to stick at approximately 45000 PSI so the fact they extracted normally doesn't mean anything.
243winxb
January 1, 2013, 11:12 AM
In revolvers pressure signs I have seen:
1) cases stick and have to be pounded out of the cylinder
When the Ruger first became available (1971) in 45 colt/45acp, seen 3 guys hot loading the Colt with Unique & pounding out the brass. Using a chronograph that had cardboard/wire for timers, pre-sky screen days. I thought they were crazy. :eek:
1) cases stick and have to be pounded out of the cylinder
When the Ruger first became available (1971) in 45 colt/45acp, seen 3 guys hot loading the Colt with Unique & pounding out the brass. Using a chronograph that had cardboard/wire for timers, pre-sky screen days. I thought they were crazy. :eek:
leadchucker
January 1, 2013, 12:06 PM
Tarry thou not amongst those who engage in intentional overloading, for they are surely non-believers, and are not long for this world. Loading-Proverbs, 21: 1.
Clark
January 1, 2013, 06:54 PM
HKGuns
Can you provide a bit more insight into why you've learned spreadsheets are bad for documentation?
If you notice in my long boring post, the number of things that can happen, they do not fit nicely in a spread sheet cell. It is more of a narrative than a calculator operation.
Read how Ackley did it.
leadchucker Tarry thou not amongst those who engage in intentional overloading, for they are surely non-believers, and are not long for this world. Loading-Proverbs, 21: 1.
Load book fundamentalism maps better onto engineering than politics.
In politics we see a polarization between collectivism and individualism.
In engineering we see a polarization between proceedurism and pragmatism.
For those in Rio Linda, that is "Do it the regular way." vs "Get'R Done."
Engineers are not just emotionless nerds, they take the time to hate each other's guts.
Read Dilbert.
Can you provide a bit more insight into why you've learned spreadsheets are bad for documentation?
If you notice in my long boring post, the number of things that can happen, they do not fit nicely in a spread sheet cell. It is more of a narrative than a calculator operation.
Read how Ackley did it.
leadchucker Tarry thou not amongst those who engage in intentional overloading, for they are surely non-believers, and are not long for this world. Loading-Proverbs, 21: 1.
Load book fundamentalism maps better onto engineering than politics.
In politics we see a polarization between collectivism and individualism.
In engineering we see a polarization between proceedurism and pragmatism.
For those in Rio Linda, that is "Do it the regular way." vs "Get'R Done."
Engineers are not just emotionless nerds, they take the time to hate each other's guts.
Read Dilbert.
vito
January 1, 2013, 07:42 PM
I'm just getting ready to get into reloading so this whole subject of deliberately creating too much pressure is a bit confusing for me. Does reloading get so boring that you get tempted to push the limits just to see if you can get away with it, without destroying your gun? Not having done reloading yet, I assumed that I would pick a powder load about midway in the published range and would only change that if it adversely affected the way I shoot when using factory loads. I can't imagine deliberately trying to find the limit when it might mean a danger to me or damage or worse to a gun that I value. But then again, I am the newbie and maybe there is something here that I am totally missing.
243winxb
January 1, 2013, 09:07 PM
Some overloads or high pressure, is part of the process. Its normal to use a starting load & work up. If we get a sign of high pressure, we stop there and pull the rest of the bullets. Then reduce the powder charge or go back to where the best accuracy was. Anytime a component is changed, its best to reduce the powder charge a bit & work up from there. Different Component = Different Pressure.
leadchucker
January 1, 2013, 09:24 PM
I'm a fairly new reloader myself, but I do know this. Having a casual attitude about overpressure can get you or someone around you maimed or killed. Take it seriously.
Centurian22
January 1, 2013, 11:33 PM
Tagging this for later reference.
918v
January 2, 2013, 10:34 AM
I'm a fairly new reloader myself, but I do know this. Having a casual attitude about overpressure can get you or someone around you maimed or killed.
Some people ride tricycles, others race NASCAR. Either activity can be done safely. Both activities have risks. That doesn't mean NASCAR should be frowned upon.
Some people ride tricycles, others race NASCAR. Either activity can be done safely. Both activities have risks. That doesn't mean NASCAR should be frowned upon.
leadchucker
January 2, 2013, 11:02 AM
Risks are acceptable only if they can be calculated and managed. Would you recommend that beginning drivers race NASCAR?
918v
January 2, 2013, 05:33 PM
Most reloading manuals have a chapter on pressure signs. A novice reloader is expected to read, understand, and apply that knowledge in his load development. Doing so is not the same thing as having a casual attitude towards pressure.
leadchucker
January 2, 2013, 07:19 PM
These are paraphrased statements I've read on this and other forums quite a few times;
Under certain circumstances, even published safe starting loads can be over pressure.
Excessive pressure does not always manifest itself in obvious detectable ways.
I'll admit that most of my loads so far are sub-standard, bordering on weak. I'm probably excessively cautious, but at least I haven't blown up any guns yet. Maybe as I gain experience, I'll get bolder.
A novice reloader, reading this thread, might indeed get the impression that he can take a casual attitude about pressure.
I'm just getting ready to get into reloading so this whole subject of deliberately creating too much pressure is a bit confusing for me. Does reloading get so boring that you get tempted to push the limits just to see if you can get away with it, without destroying your gun? Not having done reloading yet, I assumed that I would pick a powder load about midway in the published range and would only change that if it adversely affected the way I shoot when using factory loads. I can't imagine deliberately trying to find the limit when it might mean a danger to me or damage or worse to a gun that I value. But then again, I am the newbie and maybe there is something here that I am totally missing.
Under certain circumstances, even published safe starting loads can be over pressure.
Excessive pressure does not always manifest itself in obvious detectable ways.
I'll admit that most of my loads so far are sub-standard, bordering on weak. I'm probably excessively cautious, but at least I haven't blown up any guns yet. Maybe as I gain experience, I'll get bolder.
A novice reloader, reading this thread, might indeed get the impression that he can take a casual attitude about pressure.
I'm just getting ready to get into reloading so this whole subject of deliberately creating too much pressure is a bit confusing for me. Does reloading get so boring that you get tempted to push the limits just to see if you can get away with it, without destroying your gun? Not having done reloading yet, I assumed that I would pick a powder load about midway in the published range and would only change that if it adversely affected the way I shoot when using factory loads. I can't imagine deliberately trying to find the limit when it might mean a danger to me or damage or worse to a gun that I value. But then again, I am the newbie and maybe there is something here that I am totally missing.
918v
January 2, 2013, 07:58 PM
Under certain circumstances, even published safe starting loads can be over pressure.
Excessive pressure does not always manifest itself in obvious detectable ways.
The problem is that excessive pressure is a vague term. A starting load in a manual that happens to be excessive in your gun will not frag it.
You will be able to tell its excessive by looking at extraction, primer appearance, casehead appearance, casehead expansion, etc.
We are not making grenades. We make ammo. Nothing in this thread indicates a casual attitude toward pressure.
Excessive pressure does not always manifest itself in obvious detectable ways.
The problem is that excessive pressure is a vague term. A starting load in a manual that happens to be excessive in your gun will not frag it.
You will be able to tell its excessive by looking at extraction, primer appearance, casehead appearance, casehead expansion, etc.
We are not making grenades. We make ammo. Nothing in this thread indicates a casual attitude toward pressure.
R.W.Dale
January 2, 2013, 08:19 PM
The novice needs to stick with manuals and not worry about pressure guessing voodoo
To elaborate what others have said I've loaded 9mm in a encore carbine so hot its actually matching 357 mag.
Your average pressure guesser would expect that I'd have massively flat primers and deformed cases. And yet brass would come out of my encore looking better than factory first firings coming out of a glock.
Pressure signs may never actually appear even as pressures spike to twice SAAMI specs as they're just as dependent on the gun and individual chamber as it does the load being fired.
IF YOURE NEW JUST STICK TO THE MANUAL
posted via that mobile app with the sig lines everyone complains about
To elaborate what others have said I've loaded 9mm in a encore carbine so hot its actually matching 357 mag.
Your average pressure guesser would expect that I'd have massively flat primers and deformed cases. And yet brass would come out of my encore looking better than factory first firings coming out of a glock.
Pressure signs may never actually appear even as pressures spike to twice SAAMI specs as they're just as dependent on the gun and individual chamber as it does the load being fired.
IF YOURE NEW JUST STICK TO THE MANUAL
posted via that mobile app with the sig lines everyone complains about
zeke
January 2, 2013, 08:27 PM
Am another relying on chronograph and manual. If you are any where close to using max loads without a chrono, you may believe too much in yourself.
Too much velocity, too much pressure. Am of belief the pressure indicators referenced in manuals should be associated with rifle rounds, not pistol rounds.
Too much velocity, too much pressure. Am of belief the pressure indicators referenced in manuals should be associated with rifle rounds, not pistol rounds.
wanderinwalker
January 2, 2013, 09:16 PM
Am another relying on chronograph and manual. If you are any where close to using max loads without a chrono, you may believe too much in yourself.
Too much velocity, too much pressure. Am of belief the pressure indicators referenced in manuals should be associated with rifle rounds, not pistol rounds.
Agreed with "use the chronograph." I believe the caveat of primer-signs applies to rifle rounds too. You use the same large rifle primer in .30-30 Winchester (42k PSI) as .308 Winchester (62k PSI). A backed out primer can be too much pressure. Or it can be too little, as starting loads in my .30-30 will give you proud primers after firing with nice round edges. Not enough pressure to force the cartridge case back against the bolt face and push the primer back into the pocket.
Velocity and changes to velocity with respect to changes in powder charge are the best indicators of where you're operating IME.
And 918v, thanks for the range on the sticky revolver extraction. I should have added, while the primers were similar to the 9mm you posted, the headstamps and case heads weren't ironed like those cases. Those cases would have me concerned, regardless of primer condition, as they appear to have been hammered into the breech face hard.
Too much velocity, too much pressure. Am of belief the pressure indicators referenced in manuals should be associated with rifle rounds, not pistol rounds.
Agreed with "use the chronograph." I believe the caveat of primer-signs applies to rifle rounds too. You use the same large rifle primer in .30-30 Winchester (42k PSI) as .308 Winchester (62k PSI). A backed out primer can be too much pressure. Or it can be too little, as starting loads in my .30-30 will give you proud primers after firing with nice round edges. Not enough pressure to force the cartridge case back against the bolt face and push the primer back into the pocket.
Velocity and changes to velocity with respect to changes in powder charge are the best indicators of where you're operating IME.
And 918v, thanks for the range on the sticky revolver extraction. I should have added, while the primers were similar to the 9mm you posted, the headstamps and case heads weren't ironed like those cases. Those cases would have me concerned, regardless of primer condition, as they appear to have been hammered into the breech face hard.
45crittergitter
January 25, 2013, 07:30 PM
The only reliable indicator for the home reloader is a chronograph, unless you're willing to spring for a strain gage. If you're over what the book's max load velocity is, you're also over pressure. All of the brass/primer/bolt lift, etc. indicators appear only after you're way over, except when they're not, like when you get funky primer or brass behavior due to something other than excess pressure. In other words, you can't trust those indicators.
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