Yes, as long as there are no obvious signs of high pressure on the primer like flattening, cupping, or piercing, or more serious ones like difficult extraction or bolt handle binding. I would hope for a lot more than three loadings even with hot loads, but I would be confident that three firings would confirm a safe pressure level.

Other factors may override...

The more I look into it, study pressure in firearms, and use my own brain to analyze it, the more I realize that pressure and it's signs in firearms are much more complex than one part of the brass.

For example, the same pressure will affect the brass differently for a .223, x57, and a 300 belted case due to the different thickness of brass around the primer.

IMO using a single sign for pressure being okay just doesn't make the cut. A single sign of overpressure is a sign to back off, but picking a sign to work up to and ignoring everything else is more risk that I'm willing to put next to my face.

YMMV.

Other factorws may override. To wit, bullet weight, ogive shape, jacket thickness and most importantly, whether that bullet was seated into the rifling or not. Primer type used, e.g., LR or LR mag. or LP will also have some bearing here (no pun intended).

The brass case will fail long before the other components of the pressure containment system (bolt, lugs, barrel, etc.) under the parameters you've cited -- "modern bolt rifle". If the brass has not failed, or begun to show signs of incipient failure such as a loose primer pocket, then the load is, by definition, safe IN THAT RIFLE. In another rifle it might or might not be, just as in another (weaker) action, it might not be safe.

Now, the load could be on the "edge" and only exhibit primer pocket/head expansion when ambient temperatures are increased, or it could create difficulty in operating the action if there is oil in the chamber. So it may or may not be "judicious", but it is certainly "safe" in that it will not result in damage to the firearm or the shooter.

quote:

Originally posted by vapodog:

BTW I'm beginning to believe this single test is all that is needed.....what's your thoughts?

The test of loading a single case multiple times to determine if there is head expansion (most readily gaged by primer pocket looseness) is as reasonable a test of acceptable pressure for "modern bolt actions" as can be devised outside of a laboratory.

However, it must be remembered that brass varies in thickness, hardness, and capacity. A load which may not exhibit primer pocket expansion in a relatively capacious case with a hard head area might blow a primer in a lower capacity case with a softer head area. So judging a given load as "safe" in a given rifle also assumes the use of known brass.

Hey VapoDog, I want a SAFE MAX load in my rifles for hunting, but I do require a few more than "3" reloads per case.

Hot core.....I'm making assumptions that may not be true but seem to be...just checking others opinions.
asumption 1. The loosening of primer pockets will happen before sticky extraction or most other signs of pressure except flat primers.....and most of us don't get too excited over flat primers.

Asumption 2. If the primer pocket is still fine after three firings....it'll continue to be finr for the life of the case.....

assumption 3. If, in the process of working up a load, one discovers that he's getting loose pockets before the third reloading....he's over the safe limit for his components and gun.

I've been down the road with flat primers.....then using a micrometer and CHE.....but primer pockets seem to be the best test of all.....this is assuming it happens before other drastic signs like extraction troubles. I've experienced pockets opening on me.....but never had extraction problems.

I remember reading an article by Jack OConnor in the formative years of my reloading where he said if he could reload them 5-6 times, with primer pockets tight even in 100 degree temperatures then it was a safe load whether it was 50000 psi or 80000 he didn't care. In a common sense way, this may be true. If you can load them that many times, they always extract easily, using functionality as a guide they are safe. If they don't ever blow a primer or fail to extract, it would be hard to argue that they are not safe.

quote:

Originally posted by vapodog:

asumption 1. The loosening of primer pockets will happen before sticky extraction or most other signs of pressure except flat primers.....and most of us don't get too excited over flat primers.

Asumption 2. If the primer pocket is still fine after three firings....it'll continue to be finr for the life of the case.....

assumption 3. If, in the process of working up a load, one discovers that he's getting loose pockets before the third reloading....he's over the safe limit for his components and gun.

#1 I don't believe that is necessarily true. Cratering (when the primer metal begins to flow around the firing pin hole) and blown primers can happen before things get sticky. Excluding when it is caused by oil or other foreign matter in the chamber.

#2 A safe assumption if and only if there are no other obvious overpressure warnings.

#3 Yes, definitely.

I disagree with your contention that most reloaders ignore flattened primers. I was taught to stop and back off when I see them. At that level, seating too deep or a rise in ambient temperature can increase pressures dramatically to dangerous levels. I have old milsurp actions that won't handle much more than starting loads before the primers flatten, and I have newer, tighter actions that show no signs at max charges. Every rifle is different.

Hey VapoDog, I always like to see questions of this nature get on a Board because they make each person challenge how and why they watch for Pressure Indicators. Even the Beginners who read the thread and don't respond can learn a lot by following the logic.

As I think back, it always seems there are occasional exceptions to most of the Rules that we take for granted. Due to that, I like to use as many Pressure Indicators as possible.

And it seems to be best to shoot down concepts which are totally wrong like - "Velocity equals Pressure". That seems to have gotten started on the very old(now defunct) "Shooters" Board. I still see it on occasion and it indicates the people who post it really have no idea at all about what happens during the firing of a cartridge.

Good thread.

It would certainly seem that if primers became loose after three firings one should load no higher. What this means is that the brass is being pushed to it's yield point, and there is little margin left. How safe is it at that point???
Good luck!

I agree w/ hawkins here. I would expect primer pockets to stay tight through out the life of the case to insure a safe load. If you get loose PP after 4 firings instead of three, is it a safe load? I expect 5 firings min. from my cases, if not, the load is too hot or my brass is suspect (soft).

I would generally say yes.

My problem is that on one rifle, I get "flattened" primers on every load. Factory or not.

However, what do you mean by "flat"? All the way sealed in the primer pocket, slightly flatter than before firing? I don't trust just primer appearance as a sign of pressure.

Cratered primers, then I back off. Don't want to push it. Flat primers? I take with caution but check with factory loads in the same brass (Win factory loads to compare with Win. brass).

so far the results is 1 of 3 polled believe the three shot primer pocket test is a good one and 2 of three believe that addditional factors may override.

This is surprising as I would have guess much fewer would have voted to go with the three shot PP test.....

I was hoping to hear from the AI crowd but they seem a bit quiet here.....

quote:

I was hoping to hear from the AI crowd but they seem a bit quiet here

Well I currently own no AIs but a number of my own even more Imp wildcats. In pressure test with some new brass in a very tight chamber I could get more than 3 loadings in pressure ranges of 73,000+ range. Do I load to that level nope. Not in a NY second. At that level there is NO ROOM for any error. In loading, powder, primer, bullet dia etc undiscovered flaws in the rifle. Besides look at the velocity you really gain by taking prssure from the 63,000 to 73,000 range. If 50-75 FPS is that critical get a bigger case.

Who's definition of Modern?

quote:

Who's definition of Modern?

By modern It was my intention to mean any action that by it's history and reputation is clearly stronger than the cartridge case.....meaning the case will destruct before the action lets loose.

Only a few actions made after the Model 1898 Mauser are not this strong.

Too much headspace in a rifle will give you flattened primers with low pressure loads. The flat primer is not a good indication of the pressure.
Cratered primers that flow into the firing pin hole and loose primer pockets means that you have gone way too far. Case heads with extractor hole marks on them and hard bolt lift mean danger.
If your load is too hot, you don't need 3 shots, the case will tell you with 1 shot.
Even a stout but safe load has given me over 20 reloads with no case loss.

quote:

However, it must be remembered that brass varies in thickness, hardness, and capacity. A load which may not exhibit primer pocket expansion in a relatively capacious case with a hard head area might blow a primer in a lower capacity case with a softer head area. So judging a given load as "safe" in a given rifle also assumes the use of known brass.

Gentlemen, I repeat this again.

If you have soft brass that fails at an otherwise "safe" pressure, then it is not a safe load IN THAT BRASS. High pressure gas that escapes from a failed case is dangerous, whether at 49,000 PSI or 75,000 PSI.

On the other hand, if you have brass that will not fail at a very "high" pressure (but a pressure below the failure threshold of the barrel/action), then the load is "safe". The load may not be "desirable" in that it may cause excessive bore erosion and provide erratic accuracy, but it is "safe" in that firing it repeatedly will not result in either escaped gas or damage to the gun.

The very definition of safe (in an action which is capable of containing pressure considerably greater than the brass case used in it) is a load which does not cause case failure or incipient case falure, and is not so close to causing such failure that a small pressure abberation could cause such failure. Hence, three loadings of a case without notable head expansion (primer pocket loosening) would certainly constitute a "safe" load. Again, this is "safe", not necessarily "judicious", "desirable", or "appropriate". Just how "safe" such a load is might be indicated by how many additional times a case could be loaded and fired using it.

As has always been cautioned, when switching any component, cases in particular, you should back off from an established load until it is proven with the new components.

Vapodod; I hope you didn't count my post as a positive vote. You are walking the edge. Why do you think the people with the real knowledge specify pressures much below those you are operating at?.
Good luck1

I guess I'm too conservative, but I'd like to see more like 8 firing before the brass is trash. Even that might be too aggressive in some chamberings.

quote:

Originally posted by hawkins:
Vapodod; I hope you didn't count my post as a positive vote. You are walking the edge. Why do you think the people with the real knowledge specify pressures much below those you are operating at?.
Good luck1

go back to the vote poll and click on the blue tag that says "see the vote results"

Above H335 and 55 gr in .223.
Below Blue Dot and 33 gr in .223
I overload to find the limit and then back off a good safety margin so I know that I will not have a malfunction in the field.

tnekkcc,
Please let me know if your shooting on the same range as I. Knowingly overloading a cartridge to its failure point, no matter how many times one has got away with it, is not the best of practices...........JMO

A man has got to know his cartridge's limitations, or he is shooting in the dark.
If you know it through a load book, you don't know what I know.

quote:

Originally posted by vapodog:
If the load one developes for his modern bolt rifle allows that the same case may be reloaded three times (standard brass cases) and the primers still press fit into the case then is this a safe load for this particular rifle? (Assuming no temperature changes).

BTW I'm beginning to believe this single test is all that is needed.....what's your thoughts?
Choices:

I agree with the test, but my criterion is at least 10 reloads before a case has to be scrapped.......

While I do like to know a cartridge's limitations, I don't particularly like blown primers or stretched case heads, and try to avoid such things.......

quote:

Originally posted by El Deguello:

I agree with the test, but my criterion is at least 10 reloads before a case has to be scrapped.......

While I do like to know a cartridge's limitations, I don't particularly like blown primers or stretched case heads, and try to avoid such things.......

I agree long term [for expensive brass and impoortant shots], but on the front end of the load developement, I want to know what I am up against.

But for .223 and squirrells, I don't need 10 uses when Scharch will put processed brass on my door step for 5 cents each. If I am going to throw the brass away, I just need the safety margin for the gun and ammo will function.