[.38 Special]

So I'm already in hot water over on the milsurp thread, so I might as well keep digging!

Over the years I've come across various rehashings of the old methods of pressure reading (sticky bolt lift, primer cratering/flattening, shiny spots on case heads etc.) and some of those examples have been right here on this fine website. I am concerned that many folks seem to take this stuff as gospel, when in fact most of it has been soundly dispelled as myth and tea leaves. To wit:

Primer reading -- seems to be the most commonly used method, probably because it takes the least effort. It may be the most useless, too. The idea is that a cratered or flattened primer can be a sign of excess pressure: cratering because the primer cup flows into the firing pin hole, and flattening because pressure forces the primer to back into the breech face. The problems are several. First, not all primers are made with the same toughness of material, so a "safe" load -- according to primer condition -- turns into a "dangerous" load when a different primer is used. Did pressures change? Nope. So what did you learn from the primer? Not a thing. Secondly, cratered primers can show up with very mild loads, in a gun with lots of clearance around the firing pin, or even in a gun with a heavy firing pin fall. It's quite common for your old Mauser to put a real splash into a primer, simply because those old military rifles were designed for reliability above all else. This is neither good nor bad, it just is. And those "cratered" primers from Old Betsy don't mean a thing.

Now, pierced or "blown" primers are indeed telling you something. Assuming the rifle is in halfway decent shape, a pierced primer should be taken as an absolute indication of overpressure. The question, though, is "how much", and the only answer (again assuming rifle in good shape) is way too much. Something is seriously wrong here, either an accidental overload, incorrect powder, or similar misadventure. A pierced primer tells the handloader to stop right there, back up and figure out what's going on.

Then there is hard bolt lift -- supposedly indicating either that pressure is so high that forcing the brass case to "stick" to the chamber walls, and/or that the case head has extruded into the extractor cut and the extruded bit then has to be sheared by the bolt in order to extract (hence the shiny spot on the case head.) The trouble here is that, much like primers, brass cases vary in toughness. A soft case (Norma is a common offender) may well flow at safe pressure levels, while a very tough case (Lake City, Lapua) may not show any sign of pressure until SAAMI specs have been massively exceeded. The case itself is responsible for very little of the strength of the rifle/case combo, so soft cases are just as safe and useful as hard ones.

Moreover, the condition of your chamber can make a big difference as well. A rough, pitted, or rusty chamber is going to give you sticky extraction with almost any load. A precise, polished match chamber is going to tell you the opposite lie: that pressures are just fine, even if they are sky-high. (This, BTW, is why you'll find benchresters complaining about loading manuals written by lawyers -- a custom benchrest rifle isn't going to give any of the typical pressure signs until 85,000+ PSI.)

And as for the shiny spot on the case head? It's the same deal: soft brass will flow more than hard brass, and a gun with a large extractor cutout is going to show more extrusion than one with a small, tightly fitted one. Going by the shiny spot, an 80,000 PSI load is "safe" in the match rifle, while the 45,000 PSI load is "overpressure" in the old milsurp. Both "truths" are false.

Which brings us to measuring case heads. This method was actually used by the reloading manual publishers for many years. It depends upon an experienced user with a blade micrometer, taking precise and repeatable measurements at the correct area of the case, and using the same lot of cases. Few reloaders meet all those criteria, and many who think they do probably don't. Beyond that, there are still problems, like work hardening. Moreover, more recent testing has shown that even loads put together by experienced professionals using this technique have exceeded 70,000 or even 80,000 PSI, which exceeds SAAMI limits for any cartridge I am aware of. It's a slightly better method than the others listed, but it's still no substitute for actual pressure testing.

In summation, reading pressure signs is synonymous with pressure guessing, with your rifle -- not to mention health -- on the line. The idea that the hobbyist handloader can learn more about pressure by looking at his cases than the professional ballistician can learn by using several hundred thousand dollars of purpose built pressure testing equipment is dangerous and ludicrous.

[.38 Special]

Now, having written all of that, I'll mention the two "methods" that do work.

The first is simply obeying the manual. If you carefully work up a load to the manual maximum, without any pressure signs, in a modern rifle, you are almost certainly safe. I know how boring that is to a certain type of handloading adventurer, but there you go. IMO, if a person wants more velocity, he should get a different rifle. The craze for turning your .30-'06 into a .300 Magnum utterly defeats me, but whatever.

The other "method" involves velocity. Using your chronograph, you slowly work your way up to the maximum published velocity for your barrel length. Again assuming a rifle in good condition, and no signs of pressure, getting your 180/.30-'06 bullet up to 2700 FPS practically ensures a safe load. If the chrono says that bullet is going 2900 FPS, you can bet the farm that your pressures are exceeding SAAMI specs.

Which brings up one last point: SAAMI vs. "safe". The benchresters, among others, have proven that the two are not perfectly synchronous. In my time in the benchrest game -- now more than a decade ago -- it was common for shooters to grossly exceed SAAMI specs for their loads, and many of these folks could reuse the same set of cases for the whole year -- dozens of reloadings. And I never saw a blown rifle. This really just points to the facts outlined in the first post: in a carefully crafted match gun, you can get away with a lot. The same is also true, to a lesser extent, in any modern sporter from a major company. Most of these guns have a huge margin of safety, and can stand up to the adventurous handloader with no real trouble. The problem, of course, is that the pressure guessers have no real idea how much pressure they are actually developing, and no real idea if this cartridge is the one that's finally going to cause the gun to let go.

I personally don't see the sense in that kind of guessing game, considering the consequences.

HTH!

[Cosmoline]

The point is that we don't have "several hundred thousand dollars of purpose built pressure testing equipment." We have to go by what we see. That means watching for a wide array of *POTENTIAL* warning signs, checking FPS on the chrony, and cross-checking our loads and load data with multiple sources. Common sense and experience also play a large role.

SAAMI standards, particularly for European military rounds, are frankly ridiculous. They have for example neutered the 8x57JS into something akin to a .30-30 for absolutely no good reason.

[deadin]

I've always understood that the sudden onset of the symptoms you listed could be a sign of over pressure. If you are getting them from the git-go with normal or soft loads is one thing, but if at some point you start getting hard extraction, cratered primers (obviously using the same primers as before), etc., you might want to back off a tad. They're not something I'm going to ignore.

[The Bushmaster]

And if you don't normally see cratered primers in the firearm you are shooting and all of a sudden you see cratered primers because you upped the powder charge in an attempt to squeek out just a bit more fps or you are working up a new load on a known rifle. I would call cratered primers an indication of over pressure in that case.

But mostly I agree with you.

I do have a revolver that starts complaining at just under maximum powder charge...

[fireman 9731]

How about loose primer pockets after a single loading?

I have loaded some max 22-250 loads that only after a single loading a new primer would just fall right out.

I think loose primer pockets, while not being able to see right after you fire a round, are a pretty good indicator of high pressures.

[kelbro]

And now to further complicate things, we have new powders (RE-17) that distribute the pressure over a longer period. This yields higher velocities than we have ever been able to achieve with most powders. Seems like an over-pressure load with one of these new powders might have the potential to really damage an action.

[USSR]

...getting your 180/.30-'06 bullet up to 2700 FPS practically ensures a safe load. If the chrono says that bullet is going 2900 FPS, you can bet the farm that your pressures are exceeding SAAMI specs.

Quick, contact Hornady and tell them their 180gr .30-06 Light Magnum load at 2900fps exceeds SAAMI specs. :rolleyes: I'll give you one thing, .38 Special, you are relentless.

Don

[SlamFire1]

Smokeless propellants, gunpowder being a subset, have an exponential burn rate. Or maybe the slope of the pressure curve changes exponentially, I forget which is the correct description.

But what it really comes down to is that pressures don’t increase in increments like 1, 2, 3, 4, 5, 6 but increase in increments like 1, 2, 4, 16, 256, 65,536. All the devices available to us are crude measuring tools to guess the rapid rise in pressures. Of course we are going to be off when we try to measure something down to the tenth of an inch using the Pharaoh’s cubit.

But that is all we have.

Read them tea leaves and predict the future.

[243winxb]

http://www.thehighroad.us/showthread.php?t=375160 Not myth or tea leaves. Pressure Signs
The bolt will be hard to open when you are over pressure. The primer will not have a rounded edge. The web area of the brass has expanded. There is an ejector mark on the brass head. Case head separation. Primer flowing into & around firing pin. Look at the photos of some signs here. http://www.photobucket.com/joe1944usa Click for larger photos.
http://i338.photobucket.com/albums/n420/joe1944usa/th_EjectorMark_01.jpg http://i338.photobucket.com/albums/n420/joe1944usa/th_308brassina243pinchedbullet.jpg http://i338.photobucket.com/albums/n420/joe1944usa/th_lowpressurestartingonleft_01.jpg http://i338.photobucket.com/albums/n420/joe1944usa/th_223lowPressurestartingonleft_01-1.jpg
http://i338.photobucket.com/albums/n420/joe1944usa/th_223_20090302_1.jpg http://i338.photobucket.com/albums/n420/joe1944usa/th_223_20090303_2.jpg

This guy had primer pressure signs but keep shooting till he got this. http://i338.photobucket.com/albums/n420/joe1944usa/th_223Rem_20090301_001.jpg

[fireflyfather]

As far as primers having different thicknesses, any idiot who swaps components near or at max charges without working up their loads from starting charges is just that: An idiot who deserves what they get. That doesn't negate the usefulness of people watching for CHANGES in the look of fired primers as they work up their loads.

[Deavis]

Again assuming a rifle in good condition, and no signs of pressure, getting your 180/.30-'06 bullet up to 2700 FPS practically ensures a safe load.

So let me try and understand your post. All pressure "measurment" techniques that don't involve using a transducer are bogus. However, by using them and following the manual or matching test barrel velocity then a load will be safe. Safe being that it doesn't blow up your gun, rather than staying within the confines of the SAAMI specification.

Is that really what you are trying to say?

[Gryffydd]

That doesn't negate the usefulness of people watching for CHANGES in the look of fired primers as they work up their loads.
Bingo. Nobody has ever said that these pressure signs are absolute measurements. I figured everybody knew they are relative measurements only. Which is why I was really confused while reading the OP.

[USSR]

Nobody has ever said that these pressure signs are absolute measurements.

+1. For example, I cast bullets. If my bullets drop from the mould with wrinkles, the lead and/or my mould is not hot enough. If the bullets are frosted when they drop, the lead and/or my mould is too hot. I don't need to know what the exact temperature is.

Don

[rbernie]

Why not use case head expansion as the indirect measure of pressure? It seems relatively reliable, by all accounts...

[R.W.Dale]

I cite the example of 7x57 vs 270 win.

A lot of folks make the mistake of believing that some form of pressure indication will show the instant SAAMI max pressure spec is reached. The problem in this is neither your rifle nor your cases know a thing about this arbitrary number.

If a person has two similar rifles one in 270 and the other in 7x57 and you don't see overpressure signs with the 270 shooting max loads why in the wourld would you expect the 7x57 to show you anything shooting pretty much the same piece of brass. In other words if the 270 doesn't show you anything at 65,000psi why would you expect the Mauser with it's 51K rating to tell you anything till it's overloaded by at LEAST 14Kpsi:eek:

This example is given to illustrate how just through comparison to high pressure rifle cartridges that pressure signs will not show till you've already drastically gone over the line.

38's advice above is sound, the only thing you can do is stay within published and cross referenced data and use your chronograph.

Quick, contact Hornady and tell them their 180gr .30-06 Light Magnum load at 2900fps exceeds SAAMI specs. :rolleyes: I'll give you one thing, .38 Special, you are relentless.

Don

Well look at it this way if you're getting a 180grainer to 2900fps matching or exceeding light magnum ammo with a handload then yes you can in fact bet the farm you're overpressure. Supposedly light magnum ammo does it's thing by using large quantities of slower propellants loaded by some form of magic that allows for hyper compressed charges

[USSR]

Well look at it this way if you're getting a 180grainer to 2900fps matching or exceeding light magnum ammo with a handload then yes you can in fact bet the farm you're overpressure. Supposedly light magnum ammo does it's thing by using large quantities of slower propellants loaded by some form of magic that allows for hyper compressed charges

Some form of magic? Sorry, but of all the things I've learned in 30+ years of reloading, I must have missed the course in magic. However, you are right about large quantities of slow propellants. And you know what? I guarantee that the Hornady Light Magnum load is below the .30-06's 60k SAAMI pressure spec, just as my 2900fps 190SMK load is.

Don

[Clarence]

I shot benchrest for many years myself and I do have to admit that it changed my views on pressure and maximum loadings. However, there are a lot of factors to consider when making determinations. If you are using a powder that is a little on the fast side for the case capacity and bore diameter you are shooting you can still ruin your day by being less than diligent. On the other hand if you are using a powder that fits your bore diameter and case capacity, there will be a lot of latitude that you can take advantage of. The key is knowing the difference. Reloading manuals are written to provide safe loading information for the average reloader and if followed they will do just that.

That doesn't mean that if you add .1 grain more of powder than the manual recommends that you are suicidal.

For those of us who like to "wildcat" we don't have the benefit of loading manuals to follow for other than the most general of information.

YMMV

[R.W.Dale]

And how have you prooven this? USSR

[rbernie]

Well look at it this way if you're getting a 180grainer to 2900fps matching or exceeding light magnum ammo with a handload then yes you can in fact bet the farm you're overpressure.Maybe, maybe not.

Pressure exists as a curve. If the curve is relatively sharp, then you get less overall velocity. If the curve is relatively broad and flat, then you get more velocity. In many instances, we can gain velocity by increasing the dwell of the effective pressure curve without necessarily increasing the peak pressure.

[Vern Humphrey]

If a person has two similar rifles one in 270 and the other in 7x57 and you don't see overpressure signs with the 270 shooting max loads why in the wourld would you expect the 7x57 to show you anything shooting pretty much the same piece of brass. In other words if the 270 doesn't show you anything at 65,000psi why would you expect the Mauser with it's 51K rating to tell you anything till it's overloaded by at LEAST 14Kpsi
On the other hand, if the rifle can safely handle 65K in .270, an identical rifle in .30-06 or 7X57 should be safe at the same pressure level. MAP for the .30-06 and 7X57 are set low because there are many old rifles out there that are not safe at higher pressures.

The danger in loading a 7X57 hot in a modern Model 700 Rem is not that the rifle can't handle higher pressures, it's that when you depart from published data, you're in uncharted territory.

[jfh]

I'm going to stay out of this discussion about rifle pressure, simply because I am not much of a rifle reloader yet. Having said that--

There is that case head expansion / diameter measurement subject. I know that was a popular technique in the Sixties and Seventies for handgun loads--Ken Waters used it.

However, somewhere in the past few years, I believe I have read a study of this--e.g., done with pressure barrels, a run of same-brand brass, etc.--and there simply was no good correlation between diameter expansion and excess pressure. I'll see if I can chase down a link on this issue....

Jim H.

[.38 Special]

Quick, contact Hornady and tell them their 180gr .30-06 Light Magnum load at 2900fps exceeds SAAMI specs.

Hornady loads their Light Magnum series with powders you cannot get, and techniques you cannot use. But you knew that. If that's the best you can do, I'll consider my opinions unchallenged.


I'll give you one thing, .38 Special, you are relentless.

Your thread detailing the pressure guessing methods you use in working up benchrest loads was irresponsible, as is your repetition of the idea that you alone have figured out a way to drive bullets hundreds of feet per second faster than any published load while still maintaining SAAMI specs. Your "guarantee" is useless, because it is based upon the exact guessing methods shown time and again to be without merit. I think it's high time people like you stopped encouraging folks to push the limits of safety based upon little more than tea leaves.

If you want a .300 Magnum, just go buy one. They're making more every day.

[.38 Special]

So let me try and understand your post. All pressure "measurment" techniques that don't involve using a transducer are bogus. However, by using them and following the manual or matching test barrel velocity then a load will be safe. Safe being that it doesn't blow up your gun, rather than staying within the confines of the SAAMI specification.

Is that really what you are trying to say?

No. I already said what I was trying to say. You cannot grossly exceed published limits while "knowing" you are staying within SAAMI pressure limits based upon signs like brass and primer condition.

[.38 Special]

There is that case head expansion / diameter measurement subject. I know that was a popular technique in the Sixties and Seventies for handgun loads--Ken Waters used it.

However, somewhere in the past few years, I believe I have read a study of this--e.g., done with pressure barrels, a run of same-brand brass, etc.--and there simply was no good correlation between diameter expansion and excess pressure. I'll see if I can chase down a link on this issue....

It was actually used to develop loads by many of the reloading manual folks -- which is one of the reasons why published loads have been cut back quite a bit over the last few decades. Actual pressure testing equipment showed that even loads developed by professional ballisticians using the case head measurement technique could be grossly overpressure. Any technique based upon changes to the brass case are invalidated by the fact that brass cases differ one to another and change even during the process of firing.

[.38 Special]

Pressure exists as a curve. If the curve is relatively sharp, then you get less overall velocity. If the curve is relatively broad and flat, then you get more velocity. In many instances, we can gain velocity by increasing the dwell of the effective pressure curve without necessarily increasing the peak pressure.

This again seems to assume that you've figured out something the ballisticians don't know, or are at least unwilling to share with us.

If it is possible to gain more velocity without excessive pressure by using a certain powder in a certain amount, why is this information not published in any of the loading manuals?

[.38 Special]

As far as primers having different thicknesses, any idiot who swaps components near or at max charges without working up their loads from starting charges is just that: An idiot who deserves what they get. That doesn't negate the usefulness of people watching for CHANGES in the look of fired primers as they work up their loads.

Well, let's say I've worked up a load with a hard primer. I get to the maximum load listed in the manuals with no change in primer appearance. Does that mean the load is within SAAMI specs? Almost certainly. If I have a chronograph I can use that to essentially verify it. Now I change to a softer primer. The same load now shows primer flattening. Does that mean my load is now exceeding SAAMI specs? We don't have any idea. Does it make an unsafe load? Again, no clue. If we know the brissance of the particular primers we can make an educated guess, along the lines of "Well, I know the softer primer is not as hot as the harder primer, so there's a good chance the load is not making as much pressure", but even that seemingly innocuous statement cannot be taken as gospel. But again, the chronograph and the loading manual give us what we need to know: if you have not exceeded the maximum published load, and your velocity is not drastically higher than should be expected from your barrel length, both loads are almost certainly within SAAMI limits, regardless of what the primer is telling you. At the same time, there's every possibility that you can keep adding powder to the hard primer load, even up to the point of being massively over recommended charges and expected velocity, and your primers still looks just fine.

So what does all this point to? That primer condition is utterly useless as a predictor of pressure, and that the manual and the chronograph are your friends.

[.38 Special]

http://www.thehighroad.us/showthread.php?t=375160 Not myth or tea leaves. Pressure Signs
The bolt will be hard to open when you are over pressure. The primer will not have a rounded edge. The web area of the brass has expanded. There is an ejector mark on the brass head. Case head separation. Primer flowing into & around firing pin. Look at the photos of some signs here. http://www.photobucket.com/joe1944usa Click for larger photos.

Already addressed. All of the signs you mention are listed in the OP and shown fallacious. "Repetition does not equal verification" or something to that effect.

Now, I will certainly admit that some of the gross signs are obviously the results of overpressure. If you are getting blasted with hot gas and your primers fall out when you extract cases, you are overpressure. But how much? 10,000 PSI? 20,000? 50,000? And how much should you back off? Just drop the load until the primers stay put? Is your pressure then safe? Within SAAMI specs? You have no way of knowing -- unless you have stayed within the manual's recommendations and verified your results with a chrono. If you've significantly exceeded either, you are simply guessing again.

[SlamFire1]

However, somewhere in the past few years, I believe I have read a study of this--e.g., done with pressure barrels, a run of same-brand brass, etc.--and there simply was no good correlation between diameter expansion and excess pressure. I'll see if I can chase down a link on this issue

I tried this once in a 30-06, nothing correlated, took forever to take the measurements, and I never did it again.

Now, I will certainly admit that some of the gross signs are obviously the results of overpressure. If you are getting blasted with hot gas and your primers fall out when you extract cases, you are overpressure. But how much? 10,000 PSI? 20,000? 50,000? And how much should you back off? Just drop the load until the primers stay put? Is your pressure then safe? Within SAAMI specs? You have no way of knowing -- unless you have stayed within the manual's recommendations and verified your results with a chrono. If you've significantly exceeded either, you are simply guessing again.

This reloading hobby is tricky.

Take a look at Chapter 16 "Important Loading Notes" of Philp B Sharpe's book "Complete Guide to Handloading".

Mr. Sharpe has a whole chapter about how unreliable are the gross indications we commonly use for estimating pressure. In fact he says “We cannot estimate pressure”.

He says that leaking primers, blown primers, and enlarged pockets are positive indications of excessive pressures.

Cratering of primers give false positive signs of over pressure. Sticking cases are not necessarily signs of overpressure. (He actually says “This is also incorrect”)

Still these indications are better than nothing.

He also has a long section on how during load development of the “new” 308 Winchester, he and a bud developed a load. "Pressure estimates as recorded by this author ran from 42,000 to 55,000. Primers looked “good” and extraction was easy”.

He then had that load tested in a pressure gun, and it was 66,660 CUP average with a high of 68,000 CUP.

I think one of his points he was trying to make was that you can have excessive pressure, without any “signs” of excessive pressure.

I believe that if the velocities over the screen exceed published values, than so are the pressures.

But I also have one "slow" barrel, and I believe it is possible to have overpressure loads without getting the higher velocity indications.

[Howard Roark]

What about CIP standards? They have different testing procedures and in some cases different cartridge specs than SAAMI. These things produce different pressures.

Pretty much the whole world besides the USA uses CIP. Who has the right numbers? How do we know?

CIP will test handloaded ammo for pressure. Will SAAMI do that?

[fguffey]

The truth about pressure? I do not have enough ambition to get out front and claim there is no answer, those that do start with "Me and other bench rest shooters etc., etc.. then it goes straight to shooting the same case with maximum loads 50 times, again I have no interest in shooting one case 5 times, but when I do 5 maximum loads fired in the same case has an effect on the case, my cases do not have an exemption to rules. For example the case head will expand in diameter and shorten (compress) because of yield pressure, let us pretend the case head does expand due to compression .00025 thousand when loaded to maximum the first time it is fired, if fired 50 times and the same rule applied, the case head would expand .0115, copper crush, brass crush and measuring case head expansion to determine the beginning of pressure signs, if you do not believe you can do it, you can not do it. Maximum loads hammer the case head and body, the case wall should get thinner, the case head should compress, if I shot a case 50 times I would be able to compare the weight of the case with one that was never fired because I would have saved at least 5 cases for comparison, I would be able to compare the effect 50 firings had on the case wall, I would know how much brass was removed by trimming, trimming required because of the hammering, hammering that causes brass flow and or stretch ( without skid marks), if the bench rest shooter does nothing but shoot he should be able to determine the amount of brass lost after 50 firings, if the case head compresses and the case body locks onto the chamber wall, every time the case is fired, the case head moves back from the case body every time it is fired even if there is .000 head space (if the case head compresses) if there is any truth to the .00025 case head expansion.

Bladed micrometers, there was a time when shell holders could be used, as evident today when the question is asked "After reloading and firing my ammo, the case will not fit the shell holder", shell holders have too much slack for alignment to rely on them today but in the old days shell holders kept cases aligned in presses that leaned back and there was a time a mounting wedge could be purchased for presses that went perpendicular.

F. Guffey

[fguffey]

etc.."

sorry about that.

F. Guffey

[fguffey]

Again: setting with a friend that builds custom rifles at the Market Hall Gun Show, one of his customers tells him the rifle he built had head space issues, I did not get involved, the customer was asked to bring the rifle to the shop to be checked, then they were finished, I then asked to see the case he claimed had damage caused by excessive head, after examining the case I ask him if that was the only case he had and was he reloading it over and over etc., again, he did not understand the question, the case wall was .0025 thick, he carried the case in a splint/sling because there was nothing holding the brittle, cracked, split case together, he was sent to a third party for another evaluation, he was no happier with that assessment as he was with my opinion, he did not bring the rifle in to be checked and he turned down my offer to form cases for him, I suggested he spread the wear and tare out over 200 cases instead of shooting the same case over and over etc..

F. Guffey

[fguffey]

excessive head space

forgive,

F. Guffey

[Deavis]

No. I already said what I was trying to say. You cannot grossly exceed published limits while "knowing" you are staying within SAAMI pressure limits based upon signs like brass and primer condition.

Yeah, I read what you were trying to say and it could have been summed up in one sentence that most educated reloaders already know. Summary of your entire novella;

You cannot determine actual pressure by using indirect signs of pressure and therefore cannot say with confidence if your load is "safe" with regards to the published SAAMI specs.

Nothing new there. The definition of safe is the only thing that you seem to be arguing with people about. Most firearms will safely handle pressure over the SAAMI limit (9mm +P+ is a perfect example) but that doesn't mean they are "safe" if your definition of "safe" is keeping a chamber pressure beneath the SAAMI max. More importantly, your chrono is just another indirect measure of pressure, test barrel v. your gun. Their velocity/pressure may not match yours.

CIP will test handloaded ammo for pressure. Will SAAMI do that?

SAAMI provides technical specifications. They tell you how to test, they don't test. In that way, they are just like most industry standards organizations.

[DickM]

(deleted)

[USSR]

Your thread detailing the pressure guessing methods you use in working up benchrest loads was irresponsible, as is your repetition of the idea that you alone have figured out a way to drive bullets hundreds of feet per second faster than any published load while still maintaining SAAMI specs. Your "guarantee" is useless, because it is based upon the exact guessing methods shown time and again to be without merit. I think it's high time people like you stopped encouraging folks to push the limits of safety based upon little more than tea leaves.

.38 Special,

You know, it's funny, with someone with your great knowledge, I never see you helping anyone on this site with reloading questions. It's always guys like rcmodel, Walkalong, ReloaderFred and others that are doing the heavy lifting. You simply come on this site to "stir things up", after you get tired of doing the same on other sites. If you want to stay below Sierra's published "Maximum Load - Use Caution", fine, nobody's forcing you not to. But, just for your education, call Sierra at 1-800-223-8799 and ask one of their ballisticians what the pressure is for a particular maximum load listed in their reloading manual. Here is what they will tell you: "We don't have the pressure spec's for any of our maximum loads - we simply decided to stop there". So if they decide to call a 55k psi load "Maximum", when the SAAMI spec's are 60k psi, then that is what you get. Also, FWIW, I am not a benchrest shooter and am not "working up benchrest loads". And as for the idea that I "alone have figured out a way to drive bullets hundreds of feet per second faster than any published load while still maintaining SAAMI specs", I have never claimed that. I have worked with many other reloaders in this endeavor, using methods in use for probably a hundred years. So, call it guessing, or reading tea leaves, or what have you, but the truth is, a safe load in a particular firearm is safe load - Period!

Don

[R.W.Dale]

but the truth is, a safe load in a particular firearm is safe load - Period!


That may well be quite true and is really a different discussion however befitting it's own thread. HOWEVER don't delude yourself into thinking a 2900fps 190grn bullet from an 06 or the aforementioned 180grainer at 2800 isn't exceeding the saami pressure limitation for that cartridge, it just doesn't exceed the pressure limitation for your rifle. DON'T CONFUSE THE TWO!

Most pressure tested 300win mag data I can find puts 190grain bullets at velocities you get from your 06 at between 61k to 62.8kpsi burning powders just as low or slower than you. Now are you gonna tell us that your 30-06 load getting the same velocity at 60,000psi or less but with 20% less case capacity..:scrutiny:

[Tim the student]

rcmodel, Walkalong, ReloaderFred

Not to disparage anyone else, but these guys are very helpful, not just in this subforum.

So thank you to them.

[rbernie]

Pressure exists as a curve. If the curve is relatively sharp, then you get less overall velocity. If the curve is relatively broad and flat, then you get more velocity. In many instances, we can gain velocity by increasing the dwell of the effective pressure curve without necessarily increasing the peak pressure.

This again seems to assume that you've figured out something the ballisticians don't know, or are at least unwilling to share with us.

If it is possible to gain more velocity without excessive pressure by using a certain powder in a certain amount, why is this information not published in any of the loading manuals? The loading manuals show us this, as you look at the progression of powders, from fast to slow, and see how they generate different velocities for the same max pressure. That was my only point - that optimizing the pressure curve is what gives us velocity increases.

It was not an attack, only a statement.

<putting on Mod hat>

38Special - you really need to be less confrontational. Please consider that formal advice.

<taking off Mod hat>

[SlamFire1]

So, call it guessing, or reading tea leaves, or what have you, but the truth is, a safe load in a particular firearm is safe load - Period!

This is not a bad answer at all.

This thread set me to thinking, what are we worried about?

First of all, we don't want to bust the gas seal. That is the cartridge case. If you rupture the thing where it is not supported, gas will flow out and what will happen afterwards will be uncontrolled.

Second of all, we don't want to bust the mechanism. Metal fatique and all those evils are unlikely to happen in a modern, well made, 4140 steel mechanism. With modern metals if you stress the action too much, the metal will at least show cracks before it breaks. Can't say that about those WW1 era actions. Old carbon steel actions heat treated by eye ball can break in a lot of different ways.

Some people are quite willing to live with one firing per case. I have been squadded with them, the Military teams, their long range loads are so hot, the cases are not reloadable. I have picked up their once fired cases and had the primers fall out.

I can't afford that, so I try to get a much longer case life.

Standards groups, like SAAMI, they set industry standards that should be "safe" in everyone's firearm. That does not mean that some firearms won't have more "margin" than others.

[ranger335v]

"The truth about "pressure signs"

You are right. Or at least as right as those you disparage.


"Primer reading -- seems to be the most commonly used method, probably because it takes the least effort. It may be the most useless, too."

Largely correct. Actually, "flat" primers DID mean something when that "pressure gage" was first noted. Back prior to the mid or late 60s, most primers were made with concave faces. When they went flat, pressures were indeed high. No one mentioneds that today's primers come "pre-flattened" and the old rule no longer has much application. Today, it most often only shows excessive "head space".


"..as an absolute indication of overpressure. The question, though, is "how much", ..."

Nothing about chamber pressure is truly an absolute, so guesses of "how much" isn't the point; All of the signs we use are no more than indications that the pressure is TOO HIGH, the specific level is irrelivant isn't it?


"Then there is hard bolt lift -- the case head has extruded into the extractor cut and the extruded bit then has to be sheared by the bolt in order to extract (hence the shiny spot on the case head.) ... much like primers, brass cases vary in toughness. A soft case (Norma is a common offender) may well flow at safe pressure levels, while a very tough case (Lake City, Lapua) may not show any sign of pressure until SAAMI specs have been massively exceeded."

Yes, BUT...the issue is that the load is too hot for that case in that rifle, it's not given as an absolute. If the Norma case flows, it IS NOT a safe pressure level FOR THAT CASE! If a case in use turns loose it won't matter that the same load would have been safe with a different brand case. We must be safe with what we are using, what we are not using is of no help to us!


"The case itself is responsible for very little of the strength of the rifle/case combo,"

True but largely irrelivant. The "very little" strength of the case makes a lot of difference in the event. Soft cases WILL rupture or blow primer pockets sooner than harder cases. How violently a rupture occurs depends a lot on how, and how much, of the case is supported in the chamber but a soft/thin case will always give way sooner than a hard/thick one.


"so soft cases are just as safe and useful as hard ones."

Not even close to being true, at least not so with most rifles.


"a custom benchrest rifle isn't going to give any of the typical pressure signs until 85,000+ PSI.)"

Okay, that can be true. But how does that matter to those of us with common factory rifles? Or the BR guy whose rifle can handle it? And the premise of this statement seems to be in contridiction of your statement above about soft cases being is as safe as hard cases. ??


"..a gun with a large extractor cutout is going to show more extrusion than one with a small, tightly fitted one."

Exactly. The one with the larger cutout IS less supported than one in a tight chamber tho. And if it turns loose, the results WILL be noticable, right?


"Going by the shiny spot, an 80,000 PSI load is "safe" in the match rifle, while the 45,000 PSI load is "overpressure" in the old milsurp. Both "truths" are false."

How can that be false? If the tight rifle is handling the greater pressure but the old milsurp isn't, are we to assume loading the milsurp hotter would be safe? Or should we automatically need to load the modern rifle down to old milsurp levels? In either instance, THAT would be false!


"Which brings us to measuring case heads. ... more recent testing has shown that even loads put together by experienced professionals using this technique have exceeded 70,000 or even 80,000 PSI, which exceeds SAAMI limits...reading pressure signs is synonymous with pressure guessing, with your rifle -- not to mention health -- on the line."

Correct, but so what? We aren't shooting SAAMIs, we are shooting individual arms. The original data WAS safe in the arms it was developed in and the point of testing is to determine if a load, including the case, is excessive for the weapon WE use it in, right? And those who have determined those high pressue loads are NOT excessive for their weapon seems very close to some of your own earlier arguments to the contrary! All that's what the old adage to "start low and work up only if we see no exessive pressure signs" is all about, right?


"..the idea that the hobbyist handloader can learn more about pressure by looking at his cases than the professional ballistician .."

Now, in some 45+ years of reloading and reading a LOT of liturature on the subject, that's the first time I've ever seen that observation. NO ONE suggests we can do better than the pros. Instead, we are each doing the best we can with the tools and skills we bring to the table. So long as we can actually recognise that our load is getting too hot - and back off - we have done exactly what we need to do. We (usually) recognise that our hot loads may not be safe for others, and it's all done by "reading the signs".

What, or how would you suggest we do otherwise?

[Gryffydd]

I think a good example of the difference between what is the standard and what is safe, and how common sense can be applied to the process is the .45 Colt and what has been done with it for the last 75 years or so. Common loads are double the SAAMI limit for that cartridge, yet no one (other than maybe Chuck Hawks) is running around talking about how unsafe that is when used in Ruger/FA/TC firearms.

Obviously, it has gained enough acceptance to be included in most loading manuals as such, but it got that way because enough people were already doing it.

[USSR]

Most pressure tested 300win mag data I can find puts 190grain bullets at velocities you get from your 06 at between 61k to 62.8kpsi burning powders just as low or slower than you. Now are you gonna tell us that your 30-06 load getting the same velocity at 60,000psi or less but with 20% less case capacity.

Krochus,

Don't know where you're getting your .300Win Mag data from, but even the conservative Sierra Reloading manual lists many 3000fps loads for the .300WM using the 190gr Sierra MatchKing bullet. If you go to Snipershide.com and inquire about the .30-06 190SMK load, you will find it to be an established load, with many guys who have used it. Although, I must admit, when myself and Shane (MontanaMarine on the Hide) were first developing this load about 7 or 8 years ago, there were many who found it hard to believe. But, Shane plugged all the numbers into Quick Load, and I believe it came up with 58.9k psi for my particular load. Regarding case capacity, this is no different from the 7.62x51 .vs the .30-06 with a 150gr FMJ bullet. Both are able to reach 2800fps even though the 7.62x51 has less case capacity than the .30-06 and uses less powder to achieve it. Also, you have to understand, I have a 26" Krieger barrel. Would you be able to reach 2900fps with a 22" factory barrel? Not likely.

Don

[pbearperry]

I think if you have to knock the empties out of the chamber with a dowel and hammer,you might have pressure problems.lol

[.38 Special]

You know, it's funny, with someone with your great knowledge, I never see you helping anyone on this site with reloading questions. It's always guys like rcmodel, Walkalong, ReloaderFred and others that are doing the heavy lifting.

I help whenever I A) see a question that I can answer and B) it has not already been correctly answered by people like those you have mentioned. If I had known you were keeping a running tally I would have emailed you whenever I posted.

You simply come on this site to "stir things up", after you get tired of doing the same on other sites.

Your "knowledge" of things you cannot possibly know, along with a willingness to make public comments on them, is remarkable.

If you want to stay below Sierra's published "Maximum Load - Use Caution", fine, nobody's forcing you not to. But, just for your education, call Sierra at 1-800-223-8799 and ask one of their ballisticians what the pressure is for a particular maximum load listed in their reloading manual. Here is what they will tell you: "We don't have the pressure spec's for any of our maximum loads - we simply decided to stop there". So if they decide to call a 55k psi load "Maximum", when the SAAMI spec's are 60k psi, then that is what you get.

So your reaction is to essentially ignore those maximum loads and strike out on your own, using disproven methods to determine what is "safe" and what is not.

Also, FWIW, I am not a benchrest shooter and am not "working up benchrest loads". And as for the idea that I "alone have figured out a way to drive bullets hundreds of feet per second faster than any published load while still maintaining SAAMI specs", I have never claimed that. I have worked with many other reloaders in this endeavor, using methods in use for probably a hundred years.

I have not shot F-class, as you claim to, but I m led to believe that most of the loading techniques and rifle/action building methods are identical.

So, call it guessing, or reading tea leaves, or what have you, but the truth is, a safe load in a particular firearm is safe load - Period!

This is perfectly true. The point is that you don't really know if your loads are safe or not, because you don't know how much pressure they are generating and you don't know how much pressure your rifle can stand, nor how many times it can stand it. I hope luck continues to be on your side.

[.38 Special]

The loading manuals show us this, as you look at the progression of powders, from fast to slow, and see how they generate different velocities for the same max pressure. That was my only point - that optimizing the pressure curve is what gives us velocity increases.

It was not an attack, only a statement.

It was printed in response to my claim that the handloader is not going to get a 190 grain bullet to 2900 FPS in a .30-'06 while still staying under pressure spec. I think most of us understand the time/pressure curve as it relates to velocity, including the ballisticians. If just using a slower powder could get us to the 190/2900 level, I imagine those loads would have been published in the big manuals. I'm sorry you saw my reply as confrontational, but I think you are reading more into it than you should have.

38Special - you really need to be less confrontational. Please consider that formal advice.

I tend to respond in kind. I encourage posts like the one from "Ranger". I do not care for the personally directed nonsense from posters like USSR, however, and will respond to them whenever they are allowed to stand.

[Gryffydd]

I tend to respond in kind.
Let's see here. Post 1. Line 1.
So I'm already in hot water over on the milsurp thread, so I might as well keep digging!

Yeah, sounds like you were primed and ready to respond in kind.

[.38 Special]

Nothing about chamber pressure is truly an absolute, so guesses of "how much" isn't the point; All of the signs we use are no more than indications that the pressure is TOO HIGH, the specific level is irrelivant isn't it?

Not IMO, because if you are getting pressure signs (which may or may not actually mean pressure is too high) what do you do about them? And how do you then know pressures are low enough after you have taken action?

Yes, BUT...the issue is that the load is too hot for that case in that rifle, it's not given as an absolute. If the Norma case flows, it IS NOT a safe pressure level FOR THAT CASE!

How do you know that to be true?

If a case in use turns loose it won't matter that the same load would have been safe with a different brand case. We must be safe with what we are using, what we are not using is of no help to us!

You are equating brass flowing into the ejector port with a case that is about to let go. I have never seen any evidence that brass flowing into the ejector cutout IN A LOAD MEETING SAAMI PRESSURE SPECS is a risk factor. Granted, if you are using an extremely soft case -- perhaps one damaged by overzealous annealing -- then you are risk with any reasonable pressure level, but I have never heard of this happening with modern, unaltered factory cases.

The "very little" strength of the case" makes a lot of difference in the event. Soft cases WILL rupture or blow primer pockets sooner than harder cases. How violently a rupture occurs depends a lot on how, and how much, of the case is supported in the chamber but a soft/thin case will always give way sooner than a hard/thick one.

True, but only when SAAMI pressure levels have been grossly exceeded -- unless one is arguing that certain brands of case are not safe with SAAMI loads.


"so soft cases are just as safe and useful as hard ones."

Not even close to being true, at least not so with most rifles.

I have used "soft" cases for decades without problem. But I never exceed maximum loads and am usually well under them, as I decide upon what rifle to buy based upon my needs, ie. if I want a certain bullet to go a certain speed I buy a rifle that can do that with published loads. I don't buy a rifle of lesser ability on the assumption that I can go off on my own and make it into something it wasn't meant to be.


"a custom benchrest rifle isn't going to give any of the typical pressure signs until 85,000+ PSI.)"

Okay, that can be true. But how does that matter to those of us with common factory rifles? Or the BR guy whose rifle can handle it? And the premise of this statement seems to be in contridiction of your statement above about soft cases being is as safe as hard cases. ??

It matters primarily as an illustration that there are far too many variables in "reading pressure signs" for any of those methods to mean much. As for any contradictions, you'll have to be more specific. I don't don't see it.

"..a gun with a large extractor cutout is going to show more extrusion than one with a small, tightly fitted one."

Exactly. The one with the larger cutout IS less supported than one in a tight chamber tho. And if it turns loose, the results WILL be noticable, right?

At pressures well above specification. But is the gun with the larger extractor clearance "dangerous"? I have seen no evidence of it.

"Going by the shiny spot, an 80,000 PSI load is "safe" in the match rifle, while the 45,000 PSI load is "overpressure" in the old milsurp. Both "truths" are false."

How can that be false? If the tight rifle is handling the greater pressure but the old milsurp isn't, are we to assume loading the milsurp hotter would be safe? Or should we automatically need to load the modern rifle down to old milsurp levels? In either instance, THAT would be false!

The match rifle may or may not be able to handle 80,000 PSI. There's no real way to know, other than destructive testing. Which is exactly how it was determined that 45,000 PSI (or more, in many cases) is safe in the old milsurp. The shiny spot on the case tells us nothing about how much pressure the action can handle.


"Which brings us to measuring case heads. ... more recent testing has shown that even loads put together by experienced professionals using this technique have exceeded 70,000 or even 80,000 PSI, which exceeds SAAMI limits...reading pressure signs is synonymous with pressure guessing, with your rifle -- not to mention health -- on the line."

Correct, but so what? We aren't shooting SAAMIs, we are shooting individual arms. The original data WAS safe in the arms it was developed in and the point of testing is to determine if a load, including the case, is excessive for the weapon WE use it in, right? And those who have determined those high pressue loads are NOT excessive for their weapon seems very close to some of your own earlier arguments to the contrary! All that's what the old adage to "start low and work up only if we see no exessive pressure signs" is all about, right?

This strikes me as fairly circular: "Pressure signs are valid in individual rifles because if the individual rifles don't show any pressure signs they are safe, so pressure signs are valid."

"..the idea that the hobbyist handloader can learn more about pressure by looking at his cases than the professional ballistician .."

Now, in some 45+ years of reloading and reading a LOT of liturature on the subject, that's the first time I've ever seen that observation. NO ONE suggests we can do better than the pros. Instead, we are each doing the best we can with the tools and skills we bring to the table. So long as we can actually recognise that our load is getting too hot - and back off - we have done exactly what we need to do. We (usually) recognise that our hot loads may not be safe for others, and it's all done by "reading the signs".

It seems to me that any time someone suggests that one can safely exceed published loads through the use of pressure signs, he is indeed suggesting that the home handloader knows more about ballistics than do ballisticians.

What, or how would you suggest we do otherwise?

I have already suggested it: buy a rifle based upon your needs. If your needs exceed the cartridge's KNOWN AND PUBLISHED abilities, then buy a different rifle.

[.38 Special]

Yeah, sounds like you were primed and ready to respond in kind.

I assumed people would take that in the light-hearted manner it was obviously intended.

I'm naive, I suppose, but I tend to forget how much some people enjoy finding the smallest nit to pick.

[counterclockwise]

Which brings us to measuring case heads. This method was actually used by the reloading manual publishers for many years. It depends upon an experienced user with a blade micrometer, taking precise and repeatable measurements at the correct area of the case, and using the same lot of cases.

This is probably the most accurate method of checking for overpressure for most reloaders. It is still referenced in the ABC's for Reloading in the later editions. The hardness of the case head is probably not going to change over refurbishing/reloading cycles because it is already very hard and (under normal circumstances) unyielding. Bottlenecked case chambers typically pose the web of the casing (rear end of the case containing the charge pressure during firing) at the opening of the chamber. Chamber pressures that expand the case web radially beyond yield stress level should be taken seriously.

For the .308 case family of configurations ( .243, .260Rem, 7mm-08, .308Win, .358Win and .375Jag) there is an FEA analysis using LS-DYNA code at this website. It is worth going there and looking at the results. At the bottom of the report, the translation of residual expansion (post yield strain) after firing back to maximum chamber pressure is presented.
http://www.varmintal.com/a243z.htm

IMO, the problem with the primer flattening flag (primer cup assumes the shape of a .22 rimfire case) is that commercial rounds can end up looking like that. I have some fired rounds of .308 winchester hunting ammo that have severely flattened primers. Same goes for case head appearance. Take a look at some fired RSAUM cases sometime. I have photos where the RSAUM Remington ammo case head begins to extrude up the ejector pin hole. This causes some confusion in the judgement of the visual inspector.

That is a good set of photos presented up top. But, the lower right photo is not a overpressure sign. That is the end game we should all strive to avoid. I think the term "case head separation" does not do it justice. That should be "case head failure" or "case head structural failure". Damage of the firearm and threat to the user is assured in that situation. Superheated plasma at 50,000+ psi pours out the back, often times vaporizing the primer cup and anvil, dumping onto the bolt face, melting the firing pin tip, curling up the extractor claw, going on back and down inside the bolt splitting it like a log splitter, pressurizing the annular space around the bolt, and splitting the bolt carrier (in the case of an AR, pressurizing the aluminum structure of the upper receiver splitting it open, blowing down through the magazine bulging and blowing out the floor plate).

[ranger335v]

I won't argue, neither of us will change the others mind. But, I will address ONE point you mention:

"This strikes me as fairly circular: "Pressure signs are valid in individual rifles because if the individual rifles don't show any pressure signs they are safe, so pressure signs are valid."

Exactly. A given pressure in a given rifle with a given set of components assembled in a specific way is or is not safe in how well it can handle that specific pressure. It's being below or above SAAMI max specifications becomes irrelivant. A cheaply made gun can easily be hazardous with "normal" ammo. A high grade gun may easily handle pressures well above SAAMI specs, that's why the old reloading data you mention as being down graded was, in fact, safe before. That the old data was indeed safe is confirmed by the fact that it was safely used by thousands of shooters for many years.

Bottom line, it seems you and we basically differ on what constitutes a "safe" load. You have obviously agonised over all this, a lot, but I believe you have not yet arrived at the best perspective. It seems you strongly feel that anything at or below SAAMI levels is safe and anything higher is, automatically and by that single fact, unsafe. I don't, it's a lot more complex and variable than that. Common knowledge and vast "real world" experiece bears me out, not just my own experience but that of MANY others.

In fact, your own observation that soft/thin cases do tend to show signs of pressure while others do not is an assent to my position! That's what I meant when I said your statements are contridictory, and they ARE!

Again, we are loading for and shooting guns, not SAAMIs! What's safe is safe, regardless of the psi numbers produced.

[Vern Humphrey]

A given pressure in a given rifle with a given set of components assembled in a specific way is or is not safe in how well it can handle that specific pressure. It's being below or above SAAMI max specifications becomes irrelivant.
Correct. Setting aside those of us who shoot wildcats for which there is no pressure-tested data, the proper use of "pressure signs" is to start at the recommended starting load in the book, and work up slowly. If pressure signs appear, stop. Backoff and stick with the next lower load.

If pressure signs do not appear, go with the max published loads if you wish.

[Wildfire]

Hey there:
I ma not going to get into this to deep , but the one part I did notice and did not see covered. Was , The standard firing pin reach ...
A pierced primer may or may not be a PSI sign..
.055" is standard firing pin reach on most rifles. If it is too long you will get pierced primers with even a good load...

Just figured I would toss that in there ....
Keep it up you are all doing well with this............ :)

[.38 Special]

Ranger, you are admitting that your reasoning is circular. It's a closed loop of "A load that shows no pressure signs is safe because it shows no pressure sign because it's safe because it shows no pressure signs..." Meanwhile, there is absolute proof that a load can demonstrate no pressure signs while exceeding SAAMI specs by a wide margin. I suppose the argument might be that SAAMI specs aren't terribly important, but that's not an argument that I find very persuasive.

I will grant, however, that many people have worked up many loads using pressure signs and have gotten away with it. This is not because pressure signs are valid measurements of pressure (or safety), it is because modern rifles have a large safety margin and can usually put up with a great deal of foolishness. The troubles arise from folks who keep adding powder until they get pressure signs, then back off just a hair until said signs disappear. They think they are "safe", and may indeed be, but the only thing we actually know is that the load probably exceeds specification by some amount, and so the shooter is now using up some of his rifle's margin of safety -- by how much is, again, unknown. If it's significant, then he may be much closer to catastrophe than he might think.

I know we all think we are immune to a small powder measuring error, or a case neck left a little too long, or a 190 grain bullet in a 180 box, or even just a day 20 degrees warmer than the day we worked up the load, but the archives are full of pictures of defunct rifles owned by people who thought the same thing. Leaving our safety margins intact can prevent such things. Pushing them makes no sense, considering -- yet again -- that if you need a bigger cartridge you can almost always address the need by buying a bigger cartridge.

[Wildfire]

Hey :
That was MASTERFULLY Said............

[fguffey]

then there is the ideal the bullet, case, powder and primer can accelerate to the speed of the firing pin preventing the firing pin from crushing the primer (in .055 thousands of travel)?

And the firing pin spring has verified the loads as they were tested, a punched (pierced) primer is the results of the firing pin unseating, meaning the pressure inside the primer is greater than the ability of the spring to contain it. Yes a pierced primer is a sign of high pressures when it happens developing heavy loads, remedy? get a stronger spring? this could get the rifle past one warning then it would be on to the next warning.

Then, a shallow primer dent, did pressure inside the primer hammer out the dent, was the case too short from the head of the case to the shoulder or was the shallow (or no dent) caused by a short firing pin, even though the round fired?

F. Guffey

[ranger335v]

" Meanwhile, there is absolute proof that a load can demonstrate no pressure signs while exceeding SAAMI specs by a wide margin."

You haven't said it but, I will ask again, does it follow that SAMMI ammuniton specs are, by themselves, the guide to what is "safe", regardless of how well the weapon and case are performing? Disregarding completly how well or poorly designed and made the weapon it fired in is? Meaning safety in a load is dependant on an abstract pressure number, standing in isolation?

That's simply NOT so! The SAAMI specifications are no more than an AVERAGE pressure limits and a reasonable guide. But, it's NOT an absolute point that can't be crossed without the hazard of death and is quite safe if we stay under it. Again, history's experience and our loading manuals confirm that.

Check the loading tables for a 45-70. Note that most manuals have at least two, some have three ranges of loads for different rifles. And they ain't SAAMI, they are rational adjustments made to SAAMI tables in order to utilize the greater strength of newer cases and rifles and STILL be SAFE!

I'm circular? Sorry guy, but YOU are circular; "The rule is the rule, because it's the rule!"

Well, yeah... but not always. With all due respect, I have lots of hard evidence and common sense while you have the "rule" and no more.


"I'm already in hot water over on the milsurp thread, so I might as well keep digging!"

Guess so. Is that a California thing? ;)

[Grump]

The summary:

1. Loading UP to "pressure signs" is almost guaranteed to yield a load which exceeds SAAMI or CIP or other specifications.

2. A notable exception to this statement is the flattening of primers. Head clearance between the cartridge case in its forward-most position, and the boltface/breechface, *can* allow a primer to extrude and expand before the casehead moves fully back. Primers under these conditions can appear flattened or mushroomed with loads that are well below maximum specified pressures.

3. The same observation can be made regarding primer "cratering". Most often, excessive clearance between the firing pin and the firing pin channel at the boltface/breechface can result in primer metal being left in a raised ring above the rest of the primer. This can happen well below maximum specified pressures.

4. Virtually every other "pressure sign" such as sticky extraction will usually appear well beyond max-spec pressure loads.

5. No one appears to have reliably gaged the effects of "softer" brass on "pressure signs" like brass extrusion into unsupported areas of the casehead (ejector holes or grooves, etc.). Without data which includes chamber pressure AND the make of brass (including the BHN or other hardness measurement), most discussions of this pressure sign are of little guidance.

6. Measuring casehead expansion in high-pressure rifle rounds can identify chamber pressure levels which coarsely approximate factory loaded rounds (presumably within specs), but is most reliable using unfired cases of the same brand. Much more data for once-fired cases is needed before this method has a hope of doing anything other than identifying loads which are an unknown pressure level ABOVE safe.

7. IME, no one who preaches pressure signs as a reliable way to establish a max load in *your* firearm has been able to authoritatively say how far a reloader must "back off"{ of the pressure-signed load to return to safe pressure territory.

8. IME, loading to reloading manual max velocity for that exact same bullet, in that exact same case, with the exact same powder, and the exact same barrel length, is the only method to be trusted. There *may* be a +/- 100 fps tolerance for "fast" or "slow" barrels (I've had both) built in here, but further reliable study and data is needed.

I'm done.

[Grump]

That's simply NOT so! The SAAMI specifications are no more than an AVERAGE pressure limits and a reasonable guide. But, it's NOT an absolute point that can't be crossed without the hazard of death and is quite safe if we stay under it. Again, history's experience and our loading manuals confirm that.

Do you even KNOW the different types of "average" pressures for which there are SAAMI standards? It's not just one number for each cartridge.

In many ways, it's like that pesky speed limit. You can exceed it every day for decades without death or injury. But if something else goes wrong, like a tire failure or some clown clipping your bumper in a lane change, what could be easily survivable at 75 mph just might smear your brains all over the pavement at 85 mph.

How much of *your* safety margin do YOU want to "spend" each day?

[ranger335v]

"Do you even KNOW the different types of "average" pressures for which there are SAAMI standards? It's not just one number for each cartridge."

Grump, no I don't. Nor, as I'm sure you are aware, no else one quite knows what pressues are built when we fire a round. That's part of why I don't think any SAAMI spec is absolute gospel. It's generally accepted that neither CUP nor PSI are anything more than approximatations even tho they are the best we have now.

But, the question remains, by what gage does something suddenly become unsafe? None of us seek to be unsafe but perhaps the only way we can be absolutely certain we are safe could be to limit all (riife) chamber pressures to perhaps 30Kpsi; that would be safe, right? But it would also waste a LOT of user potential too! Saying we "can't be too safe" can be taken to such silly limits that we couldn't do anything. And it would be to attempt to load an early 30-06 Springfield '03 to 55 Kpsi, what is generally considered quite safe in more modern rifles, even tho SAAMI says it should be safe.

The issue here is, "What determines what is actually safe?" Is it the ability of the weapon AND cartidge to easily withstand the presssure or is it 55 or 60 or 65 Kpsi and no more? I say it's the combined combonation of the cartridge and action to retain the pressure, not some line drawn in the sand, so to speak. We had better know what we are doing, and how to keep track of its effects because no book can guide us with any high degree of accuracy. BUT, understand that I am NOT saying to ignore the SAAMI pressure guidelines, I'm only saying to use them rationally. And without playing Chicken Little!

Anyone doubts his ability to "read pressure signs" better stick with book loads. But then my buddy that gets blown primers in a near new Mod. 70 with mid-range charges of Varget in .22-250 would say you absolutely can't totally trust the books either! NO, I don't know what pressure that load was but we both can read pressure signs well enough to know that load was much too hot, no matter what our load manuals say!

Knowledge of what we are about, and good judgement keeps reloaders safe. Blind, irrational fear of a table of numbers does not.

[.38 Special]

Ranger, IMO you've got your toes right up to the "strawman" line. Nobody is saying that SAAMI standards are "absolute gospel". They are, however, standards put together by people who, frankly, know more about the subject than you and I. My argument remains that the pressure guessers are fooling themselves if they think they can use SAAMI specs as "suggestions" or "guidelines" -- especially when they strike out on their own to determine for themselves how much pressure their pet rifles can take.

[.38 Special]

Let's try a few theoreticals for those with advance abilities to read the signs:

You have a rifle with a very rough chamber. The mildest loads in the books work fine, but even the low-middle loads produce difficult extraction. Are those loads dangerous?

You have a rifle with an extremely smooth chamber. It does not show signs of sticky extraction even with loads exceeding the book maximum by 20%. Is this load dangerous?

You have a rifle with hand fitted lug recesses. The bolt can be lifted with one finger after firing SAAMI proof loads. Is this load safe? How many can be fired in the gun before metal fatigue becomes a factor?

You have a rifle with uneven lug recesses, but still within factory tolerances. Bolt lift requires force even with factory loads. Is this rifle dangerous for use with factory loads?

And one more: what if you change primer brands in that Varget load that blows primers, and the new primers hold up just fine? Do you assume that pressures changed? Or do you assume that primer cup thickness made the difference? Do you actually know anything about the pressure of either load? Is one more or less likely to blow the action?

[ranger335v]

Actually I've lost interest. You have steadfastly ignored my questions and still haven't yet said what you really believe is "safe." But, it don't really matter, do it?

Example: " Meanwhile, there is absolute proof that a load can demonstrate no pressure signs while exceeding SAAMI specs by a wide margin." You haven't said it but, I will ask again, does it follow that SAMMI ammuniton specs are, by themselves, the guide to what is "safe", regardless of how well the weapon and case are performing? Disregarding completly how well or poorly designed and made the weapon it fired in is? Meaning safety in a load is dependant on an abstract pressure number, standing in isolation?"

I give up, why bother trying to discuss anything with a non-responsive poster?

Now, your new "hypothetical" questions are unreasonable, to the point of being silly. The man's primers aren't pierced, they are "blown", technically meaning the primer falls out of an expanded pocket. No real "max" load + 20% would allow the bolt to be opened with one finger. The rough chamber question is foolish, etc. All nonsense.

You certainly do, by implication but still without clearly stating anything, strongly suggest that you believe SAAMI specs absolutly define what is or is not safe. Or maybe it's your writting comprehension.

You simply show no acceptance that reason can come into play with book loads, including no response to my example of a low number 1903 Springfield or a Ruger#1 in .45-70. You simply refuse to say or't define what you do mean, leaving me nothing to work with!

It appears you aren't interested in a dialog, only in argument. I'm not. So, have a blissfully happy day. :banghead:

[jon_in_wv]

It appears you aren't interested in a dialog, only in argument.

It does appear to be his pattern if you look at some of his other posts.

[.38 Special]

Actually I've lost interest. You have steadfastly ignored my questions and still haven't yet said what you really believe is "safe." But, it don't really matter, do it?

I've answered all of your questions that I am aware of, and I have given my opinion of "safe" throughout the thread.

Example: " Meanwhile, there is absolute proof that a load can demonstrate no pressure signs while exceeding SAAMI specs by a wide margin." You haven't said it but, I will ask again, does it follow that SAMMI ammuniton specs are, by themselves, the guide to what is "safe", regardless of how well the weapon and case are performing? Disregarding completly how well or poorly designed and made the weapon it fired in is? Meaning safety in a load is dependant on an abstract pressure number, standing in isolation?"

No, it follows that a rifle in good condition is almost certainly going to be safe with published maximum loads. A rifle that is not in good condition is probably not safe with any loads. And the idea that SAAMI numbers are "abstract" is startling to me. Do you really believe those numbers don't have a basis in reality?


I give up, why bother trying to discuss anything with a non-responsive poster?

IMO you have mistaken "responsiveness" with "agreement". I think you are wrong and I am trying to demonstrate it by responding to your posts.

Now, your new "hypothetical" questions are unreasonable, to the point of being silly. The man's primers aren't pierced, they are "blown", technically meaning the primer falls out of an expanded pocket. No real "max" load + 20% would allow the bolt to be opened with one finger. The rough chamber question is foolish, etc. All nonsense.

I was unaware that there was a dictionary definition for "blown" primer. I have personally seen rifles fired with SAAMI proof loads that showed no signs of pressure whatsoever, including sticky bolt lift. And I personally own a rifle with a chamber so rough that sticky extraction occurs with starting loads. If this is all "foolish nonsense" -- nice effort at "dialogue", BTW -- then it should be simple for you to explain why.

You certainly do, by implication but still without clearly stating anything, strongly suggest that you believe SAAMI specs absolutly define what is or is not safe.


I'm not implying anything. I am clearly stating my position. Anything else you are reading into it is your own problem.


Or maybe it's your writting comprehension.

When making fun of your interlocutor's intellect, it's generally a good idea to spell it right. Not that that particular insult makes sense even when spelled correctly...

You simply show no acceptance that reason can come into play with book loads, including no response to my example of a low number 1903 Springfield or a Ruger#1 in .45-70. You simply refuse to say or't define what you do mean, leaving me nothing to work with!

And yet I'm the one with the comprehension problem...

It appears you aren't interested in a dialog, only in argument. I'm not. So, have a blissfully happy day.

Pot, kettle, etc. :rolleyes:

[jon_in_wv]

Nor by attacking other posters, attacking thier preferences, childish slams at their opinions, or total disrespect. You should heed your own advice.

[.38 Special]

Do you have anything to contribute, Jon?

[RoostRider]

Seems like you guys are taking this a little too far....

Leaving our safety margins intact can prevent such things. Pushing them makes no sense, considering -- yet again -- that if you need a bigger cartridge you can almost always address the need by buying a bigger cartridge.

Thats what I was thinking.... I have a .223 to do the things that a .223 does well.... and a .308 for the things it does well.... I didn't buy a snubbie .38 thinking "oh well, I can load it to .357 power"... I bought the snubby for what it does well (carry around).. I bought a +P capable gun, because I wanted all the 'edge' a .38 spcl. can give.... I load to ~+P and call it good... I usually test a few a little 'hot' just to see (taking into consideration the gun of course)

That being said, I don't push pressure too high, but I have been known to work up a load over the manual using pretty much all of the 'guess' methods together.... I know it's not foolproof but I also know the gun in question and the cartridge are capable of going over the top as far as the manual is concerned... eek it over a little bit, test a few rounds, check for signs, call it good for 'tops' out of that cartridge...

I think the trick is not getting carried away with what you want out of your gun... and changing guns if that is what you need...

Why would someone push the limits of a gun/cartridge 's capability by foregoing reasonable safety margins? but I also think the realistic margins are different for different guns... brass failing is one thing (and clear evidence of something way out of whack), but your barrel failing is a whole nother... just get the right gun and be safe...

Unless, of course, we are talking about a testee's issue (double meaning intended.... get it?... lol... I kill me)... and the real issue is to push something further than it is supposed to go.... then by all means.... just don't stand near me at a range and 'test' your theories.... *that's what worries me most....

Hope I haven't pissed anyone off here.... since I kind of agree with both takes... lol

[.38 Special]

FWIW, I'm not arguing that exceeding manual maximums automatically puts you into danger territory. If the max is 50 grains, 51 grains isn't likely to be disastrous -- especially if you are simply attempting to get your bullet up to advertised velocity.

It's the folks that argue that the manuals are all put together by lawyers and view pressure data as mere suggestions; that figure they'll just add powder until something bad happens and then back down just until the bad stuff goes away, that I think are flirting with disaster. This seems to be fairly common, as evidenced by threads like this one. (http://www.thehighroad.org/showthread.php?t=468231)

[ranger335v]

"I was unaware that there was a dictionary definition for "blown" primer"

Interesting admission. Yes, there IS a commonly recognised "dictionary definition" of a blown primer, it's clearly definened by the highest photo in post #10.

Your obvously great knowledge has covered significant gaps, making you fail to see there's a lot you are unaware of. But it really makes no difference does it? Nor do Ad homanum (sp) slurs matter at all, it's all in fun, right? :)

(What you have posted so far makes no real sense!)

[USSR]

FWIW, I'm not arguing that exceeding manual maximums automatically puts you into danger territory. If the max is 50 grains, 51 grains isn't likely to be disastrous -- especially if you are simply attempting to get your bullet up to advertised velocity.

Ha, that's choice, .38 Special. When I listed my handload that is 0.7gr higher than a published load, here is what you had to say:

The poster who goes by the screen name of "USSR" uses old wive's tales in lieu of pressure testing equipment, and also has the habit of recommending dangerous reloading practices to people who may not be experienced enough to recognize the hazards therein.

followed by:

I've just been informed by a moderator that I am brushing up against the rules here. Apparently it's okay to recommend that users blow themselves up, but not to suggest that they don't.

As previously stated, you only come on THR to argue, and you trash anyone that stands up to you. So, reload the way you want, and just leave us guys with more experience than you the h~ll alone.

Don

[.38 Special]

No, Don. You're playing games. The line you quoted was not in response to you exceeding max loads by .7 grains, it was in response to you claiming that one can safely ignore max loads if you pay attention to pressure signs.

In all the responses you have made to me -- including all the personal attacks -- you have never actually addressed any of the points I have made re. the uselessness of reading pressure signs.

Between you and ranger, I'm getting an earful of "You're making personal attacks" along with "You're a big doodoo head", and "You don't answer any of my questions" along with "I'm not going to answer your questions". Which is amusing, if not terribly productive.

So, anybody want to talk about the thread topic?

[.38 Special]

"I was unaware that there was a dictionary definition for "blown" primer"

Interesting admission. Yes, there IS a commonly recognised "dictionary definition" of a blown primer, it's clearly definened by the highest photo in post #10.

You're right. That is "a" definition. The trouble is that it's not "the" definition, and I have heard the term used in reference to pierced primers many, many times.

The difficulty, it seems to me, is that you are more interested in scoring points than addressing the thread topic. Not much I can do about that, I guess.

[Gryffydd]

This is awesome. OP starts a thread with a post that's basically stating the obvious, but slightly misguided, very condescending and pretty much irrelevant--for the specific, admitted purpose of stirring things up. Then accuses others of only trying to score points rather than contribute to the conversation.
Thanks for the entertaining thread :D

[.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"! :confused:
------------------------

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! :neener:
--------------------------------------------------------

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]

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.

http://i183.photobucket.com/albums/x37/Walkalong/popcornbigbox.gif

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 WilsonI 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.
:fire:

[Maj Dad]

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. :cool: