This is how I've been determining MAX safe working PSI for decades...how do you feel about this technique? It has worked for me.

Please see video below.

https://www.youtube.com/watch?v=2APC4xixPtY

Similar. But in a M98 you don't get that indicator. He does need to re-edit since the last case comes out of the rifle and he looks at it and it now unfired.

New load , new bullet, powder etc. I will take and work up to what I feel is max in my rifle. Observing the case head, measure foe head expansion and use as many published resources I can fine. Establish what I feel is max for that rifle, powder, case and bullet. It might be above a book max. Then work up a load under that max. Then track how many reloads I get from my brass and adjust the max down if needed.

I used to really push my loads and brass. Then after really studying the "SMALL" velocity gains for that extra pressure I have become a touch more conservative.

quote:

after really studying the "SMALL" velocity gains for that extra pressure

This statement needs to be at the front of every reloaders bench!!!!!

quote:

Originally posted by Ackley Improved User:
This is how I've been determining MAX safe working PSI for decades...how do you feel about this technique? It has worked for me.

Please see video below.

https://www.youtube.com/watch?v=2APC4xixPtY

_________________________________________

If it floats your boat for decades, fine hunkey and dorey. The problem with we old curmudgeons it perhaps that we have a tendency to hang on to the past and let modern technology and intelligence sweep by us !

With some trepidation and misgiving I have to say that I will definitely NOT being passing along to my Grandson such antiquated methods except as an historical moment from the past.

We humans are advancing in terms of light years. In my life time incredible.

There is a MUCH better way to do it.

quote:

There is a MUCH better way to do it.

Being what?

Hmm run out and spend $600-800 for a Pressure Trace II system so I can match my loads to what a factory load reads in my rifle. No telling what that pressure actually is. Or should I stop say a 280 at pressures below the 270 because factory does? For wildcats with no factory using their "fudge" guess gets you how close?

I used an early strain guage system in the past. It did allow me to quickly find a max for a new load. Once I found the max for an early one. That was found by the old antiquated method.

Being what?
If you plan on relying on a computer generated pressure for your set of components; good luck; you will get what is right for your particular barrel and brass only by accident. And if your grandson does not know these old, basic techniques then he can't safety reload; there is no modern substitute for them. (not endorsing the brass reading thing, though, although it does work)
And if you want a direct reading pressure system like a piezoelectric sensor, plan on spending a ton of money for it.
Here is my method; if the primer pockets are still tight, the load is good. If not, back off on the powder. Primitive, maybe, but effective.
This topic has been beat to death recently.

The subject was already beat to death 30-40 years ago - so it's Deja vu all over again for me.

Bulged/flattened primers, split necks, case head separation are a cumulative abuse with loading, time, case life, numbers of reloads.

The Trace II glue on strain gauge is indeed pricey. Internal ballistics software is too something of a SWAG.

There isn't any dearth of reloading data on the internet. It is available in super abundance. Powder and cartridge manufacturers have it all over. They are very forthcoming.

Too you can buy a box of commercial ammo and then extract components. Pull the bullet. Weigh the powder. Duplicate the load.

Please don't think that I am disparaging the visible signs of pressure, flattened primers, hard bolt opening. I'm only saying that there is more to the curriculum to cover everything.

Please take the the following as our own experience.

Things we have actually done, and the results we have gotten.

In each occasion, the results only apply to that particular rifle, at that time.

A few years ago, we decided to see if we can blow up 3 separate rifles, by overloading them.

The rifles were a BSA in 243 Winchester.
A BRNO 505 in 308 Winchester.
An Enfield in 303 British.

All the rifles were in perfectly working condition.

The fastest powder we have was Hercules Bullseye.

All three cases had a capacity of 35 grains of Bullseye.

We set them up down our tunnel, and fired each with a fishing line.

The BSA in 243 Winchester blew up into pieces. And any shooter firing that rifle would have sustained very serious injury, if not death.

The BRNO in 308 split the stock by the magazine, and no serious injury would have occurred had someone being firing it.

In fact, we used a hammer to open the bolt, and fired another round in it, where the piece of the stock came off - where the crack was.

The shooter might have gotten some injury in his left hand.

The Enfield 303 had no damage at all. The action held very well.

We have done load development on an endless number of rifles.

Ranging from 17 caliber wildcats and factory, all the way to 700 NE.

We have tried a pressure Gage, we have tried looking at the results from the fired brass, and the action after the shot.

We have purposely over loaded rifles to the point of having to use a hammer to open the bolt.

Sometimes these extremely overloaded rounds gave us very high velocities.

Sometimes the velocities were hardly higher than a normal load.

After all these years, we have reached a point that whenever we are developing a load for a new rifle - whether it is a factory gun or built here - we stop load development as soon as we see any sign of excessive pressure.

Normally this done by feeling the bolt, or signs on the fired brass.

This mostly involves flattened primers or heavy extraction.

Ken Waters did not use any fancy 'new' equipment. Just 'real world sense,tools and a lot of trigger time'.
My younger friends just do not seem to comprehend the amount of information that can be gleaned from words on paper !
If it is not electronic, it is a waste of their time. NOT !

What is the MUCH better method ?

I am a dinosaur, but willing to learn !

quote:

Originally posted by Saeed:


This mostly involves flattened primers or heavy extraction.

Primer flattening is very much the same method as the copper crusher pressure measuring system used for years. It was not an absolute pressure measure but a comparative one based on use of copper cylinders with known crush rates. Primer flattening is a similar comparative measure used to indicate pressure in the same rifle using the same primer each time.


Both primer flattening and ease of bolt lift and case extraction are indicators of pressure that have stood me in good stead when reloading over the years.

Me too.

I agree with EVERYTHING above.

None the less I think that we have to separate the various signs and signals and categorize them to get a full understanding.

The illustration about different guns blowing apart at different circumstances is an excellent point. There is no uniformity that is dependable.

Other point.

Split necks and case head separation are two entirely different scenario's. Two different circumstances. Two different causes and effects.
It is important to understand what causes these two different failures.

Loose and ejected primers and hard bolt opening are too certainly very positive signals but there are variables. So to analyze what you did wrong, it takes some forensic investigation.

We certainly have an overabundance of cartridges and powders today. Choosing the right burn rate and composition, ie. spherical, flake, cylindrical, single component or double component, *( Or even now triple component ) stand alones or blends that some powder company's now engage in bring this understanding to a new level. It is an enhanced sophistication that I, personally, do not have any objection to.

We old timers will cash it out some day. My philosophy is to school our upcoming younger generation to the maximum and be meticulous in conveying the vital information.

I was stunned the other day by a news report that 70% of two year olds know how to navigate the internet !!!!!!!!!!!!!!!!!!!

______________________________________

As a foot note, you can be tricked into false interpretations with too small loads that don't swell the case out and seal effectively. Just another heads up.

Keep in mind t hat these pressures are beginning to make the brass yield. Once
in yield there is not much strength left.

All you who determine pressure by flattend primers, what brand and what primer do you use?
Do you have a chart that interpolates from one brand to another?
Say i get flattend primers using a Rem 6½ and then change to a Rem 7½. Now suddenly the same load gives no signs of "high pressure", has some unknown pixie dust in the Rem 7½ primer lowered the internal pressure?

They are not created equal you know!


So flat primers is no way to determine internal pressure it is a pure BS indicator!

quote:

Say i get flattend primers using a Rem 6½ and then change to a Rem 7½. Now suddenly the same load gives no signs of "high pressure", has some unknown pixie dust in the Rem 7½ primer lowered the internal pressure?

To me if you haven't worked up the load with a certain primer it is hard to judge simply by looking at the primer. Your example is good. Same issue if you swap brands.

Just looking at a primer you can't say wow that is a 70000psi load. But if you watch them as you work up you can see when you get to a point the primer is starting to flow. Be it 62,000 or 67,000 that is reach max for that load that rifle.

It doesn't matter what the actual pressure is; you read the primers and brass you are using for that specific set of components, and barrel, and if the primers are very flat or extraction is hard, then you are at the maximum pressure for your set of components, regardless of what it actually is. So, as Ram said, You can't say it is a particular pressure but you can say it is max for your rifle, primer, brass.
Here is an example for you; our M256 tank cannon works at a pressure above 100,000 PSI. How? We use steel cases and steel primers that are screwed into the case. We could do it with rifles too.

Sorry Dane but your example violates one of the fundamental practices of safe reloading.
One does not 'just change from a Rem 61/2 to a 71/2' (in your example) and go shoot.
How many times have you read 'If you change one component, start load workup over' ?
Different component COMBINATIONS creat different pressures AND yet even greater differences in different rifles.
I thought the op asked a/b finding max pressure---safely.
Changing components willy-nilly will not answer the question nor is it a safe/smart practice.

Using flattened primers to get an idea of high pressure is really very simple.

Use the same primer - makes no difference what make it is - until you see signs that that particular load has a higher pressure than one would consider normal.

There is no rocket science involved in it at all.

To use the technique in the video, you must have an ejector port (Rem 700) or similar port on the bolt-face for this to work. But, I was hoping for comments on the specific technique used in the video.

All bolts have either a hole or a slot in the bolt face so that concept can be used on all bolt actions; but, I would rather look at the primers.
I suppose the "brass flowing into the ejector hole" idea has merit. But I think the primer reacts first.

I worked on two rifles & calibers that did not have modern pressure load data - 6.5X55 & 280 Ack. This was about 15 years ago when all the data was for M96 rifles or below 270 Win pressures.

My final conclusions for safe loads were

1 Use a chronograph to get the ball park velocity with the right powder bullet etc.
2 Any ejector hole mark on brass is too hot!
3 Measure case head expansion if you have the patience - I did for over 200 rounds each - I even made up little jigs to make sure that each measurement was the exact point for each case.
4 BUT - I found that if the load was hot enough it could even expand the case rim and even bend it a tiny bit during difficult extraction. This bent rim would trough the case head measuring point off!
5 Lose primer pocket was a major clear indicator - never fails to send a warning
6 Finally I started measuring the fired primer itself - Here I found that the primer became flatter and wider until it started developing a hat brim. That was a clear indicator too that the primer pocket must be expanding.

Since then I have developed loads more recently for the 9.3X62 & 416 Rigby with modern pressure. I just used the chronograph and the fired primer check to stop at max loads.

All extractions are easy and bolt just falls back.

Just a heads up Guys. Generally true under common accepted practice.

Some shooters do not follow the common practice. Particularly big Bore Macho's *( He Men ! .

Not always true under the circumstances of big bore shooters who shoot lead bullets at reduced loads to conserve powder, economize on bullets, and reduce recoil.

Reduced loads will fool you and foul your general interpretation by showing the signs you think are high pressure but are actually due to too low pressure that doesn't seal the cases against the walls but allows blow back.

quote:

Originally posted by dpcd:
All bolts have either a hole or a slot in the bolt face so that concept can be used on all bolt actions; but, I would rather look at the primers.
I suppose the "brass flowing into the ejector hole" idea has merit. But I think the primer reacts first.

Of course there are some combinations that indicate high pressure on primers but are not. My Schultz and Larsen rifle in 7x61S&H gave very high pressure signs on the primers in Norma Factory ammo but this ammo gave no problems with extraction or case life when reloading and was superbly accurate ammunition.

When working up loads I did at times get high pressure indications, ejector scuffing on the case head along with flattened primers so backed off of course. I resized to headspace the belted case on the shoulder which extended case life. The no-go gauge would not chamber so headspace was good.

Here is a fired factory load case.

were those reduced recoil 270 factory loads? normally factory 270 loads scare me

first and foremost, i NEVER work up max loads for a gun with new brass -- oh, i'll find the safe first time loads - generally, for me, that i -.0275 and exactly the medium book load ..



this looks like most factory 7rem/270 loads .. of which i would immediately back off 2-3"


To put what Paul said into my words

the last 100 fps is VERY expensive in pressure in fact, i say that all the time

The thing is, users of wildcat or AI cartridges MUST load to the limit of the brass in order to achieve the performance figures they want and need. If they can then compare these levels of performance to those acjieve by standard cartridges loaded to SAAMI standards, they can be happy and justified in their choices. Regards, Bill

quote:

Originally posted by Bill Leeper:
The thing is, users of wildcat or AI cartridges MUST load to the limit of the brass in order to achieve the performance figures they want and need. If they can then compare these levels of performance to those acjieve by standard cartridges loaded to SAAMI standards, they can be happy and justified in their choices. Regards, Bill

I load my wildcats and non-wilcats exactly the same way in regards to PSI.

quote:

The thing is, users of wildcat or AI cartridges MUST load to the limit of the brass in order to achieve the performance figures they want and need

Bill,
I take exception to lumping all wildcatters and AI users into that category.

I will admit that many AI users will load to case limits. Heck I even did it myself 30 yrs ago. But there are a lot of us that are happy with what we get for our wildcats give us loaded to normal acceptable pressures.

Your comment rates in there with saying ALL cops will shoot first and ask questions later.

I have to agree with Paul -- like saying "all reloaders without a chrono are delusional" . pretty sweeping statements..

but, yeah, let's talk facts.. *IF* i had a 7x57 AI, of friggin COURSE i have to use a firformed case to even start, as super ultra max 7x57 standard brass and loads would
look
safe
in
that
chamber
every
time

Since we as reloaders are not privy to the proper equipment, and add to that the proper equipment does't really work much better, we use the old time tried and true, guess and by gosh methods and by golly they still work pretty darn good..Her is my method:

I look for:
1. Flat primers, especially with a dark ring around the perimeter. Primers can be a poor indicator, but don't ignore them and by using the same primers all the time you will get a feel for them.

2. An ejector indention on the case head tells me to cut back a grain, maybe two two.

3. A crack as opposed to a boom is really time to back off you just passed max, go to jail directly to jail.

4. I mic fired case heads, starting with the first fired case although I also measure the newly fired factory case before and after firing. zero expansion is a good idea, some of us are experienced enough or dumb enough to go past 0 expansion my a few thousands expansion, and some go overboard and get away with it. mostly I mostly go with "0" case head expansion. 100 FPS will never impress a deer or elk.

5. blackened case necks means too little powder or the wrong powder.

6. I always use the chronograph and feel one is neglectful not to own a chronograph these days as a $100 unit is plenty accurate.

7. Very important is I use one case and finish with one case paying attention to the above and I expect to keep fairly snug primers and no loose primers for at least 10 reloads per case, this tells you a lot...

8. A slightly sticky bolt lift says you done done it and better back off a grain or two.

9. I always use a powder that fills the case to at least the neck/shoulder junction and half way up the neck is even better, you will never double load that way.

Keep in mind that just one of the above indicators may or may not mean much but two or three together tells you plenty, pay attention.

That's the way I do it, others may do it differently, but I have never blown a gun up or damaged a gun. Sometimes I make adjustments one way or the other, and sometimes I back off simply because I get a bad feeling about working up a particular max load..Your actually flying by the seat of your pants wheather you will admit it or not, but taking all the above steps into consideration has worked for most of us for the last century or two. Be careful not to get too technical and don't get careless or too brave, respect the process and know the pitfalls. Come hell or high water if you load enough you will blow a primer on rare occasion, so always wear eye protection, glasses are fine. and that load was too hot btw!

A lot of good information here.
A couple add ons:
Flatten primers also appear when head space is too loose.
Soft brass vs. hard brass.
One example was some Cavim brass showing hard lift yet with the same load in other case manufacturers the pressures appeared mild.
The Cavim brass was 7.62x51 Nato and not really .308.
This also cropped up with some Norma brass in the sixties .

Also loose primers can be the fault of the primers or brass and not high pressure. When Winchester abandoned the plating on their primers this happened. Weak brass can have loose primers yet the pressure may not even be near a danger level.

Hard lift can occur if the bolt face is not truly perpendicular to the cartridge. This has happened when opening up the bolt face to accept a belted cartridge.
roger

quote:

Also loose primers can be the fault of the primers or brass and not high pressure. When Winchester abandoned the plating on their primers this happened. Weak brass can have loose primers yet the pressure may not even be near a danger level.

I agree 100% that poor/weak brass can allow the primer to move, flatten, be loose or leak at a pressure far below what we would normally view as max for a cartridge.
BUT, to me then that still becomes a max load identifier for that particular primer, bullet etc.