We have a lot of new Reloaders join our group each year - Welcome Aboard. And we have a lot of seasoned Reloaders who all go about Reloading just a bit differently from each other. Makes for good discussions to see all the different Methods.

Some of the Pressure Indication(PI) Methods are very subjective and seem to only be worthwhile after the person has used them for some time period. Needless to say, this makes those Methods a bit difficult for a Beginner. Some are more precise, require measurements with accurate measuring devices, and have a short learning curve. Some are old Tales that should never have been started because they are very misleading or totally wrong. And we have some that only fool the users into thinking they are gaining something when they have done nothing but wasted their money.

When as many PIs as possible are used Developing Loads, the user quickly learns some are better than others, but most contribute a bit to the overall Pressure Indications.

I'm going to list as many things I've seen used as PIs as I can think of. It would be interesting to see how many of them you use, or perhaps you use some I'm not aware of at all. If you use some which are not listed, I'd like to hear about them, where/how you leared about them, and how you go about using them.

Question:
Do you use Primer Pocket "Shortening" as a PI? If you use a Primer Pocket Squaring Tool to clean the Primer Pockets you will occasionally see more Brass removed as the Pressure Increases. (Subjective)

Choices:
Yes
No
Occasionally

Question:
Do you use Case "Lengthing" as a PI? Depending on how well the Chamber Dimensions and Die Dimentions match, this can be a PI indicator, or it can be totally misleading. (Subjective)

Choices:
Yes
No
Occasionally

Question:
Do you use Primer "Flattening" at the corners as a PI? Depending on the Headspace, specific Lot/Mfg of the Primers this can be a PI or totally misleading. (Subjective)

Choices:
Yes
No
Occasionally

Question:
Do you use "Tight" Bolt Lift as a PI? This is normally only practicle in a Bolt Action rifle and typically indicates the Pressure is beyond what is considered a SAFE MAX. (Subjective)

Choices:
Yes
No
Occasionally

Question:
Do you use Primer Pocket Expansion as a PI? We recently covered how many Reloads before the Pockets become loose are acceptable, so I won't specify a number. (Subjective)

Choices:
Yes
No
Occasionally

Question:
Do you use Case Resizing effort as a PI? On heavy Loads, there is typically more effort required to Resize the Case. This would not be noticable to those who Neck Size only. (Subjective)

Choices:
Yes
No
Occasionally

Question:
Do you use Neck Splits as a PI? The heavier a Load, the more the Case becomes "Work Hardened". This means you will need to Anneal the Case Necks more often if the Loads are heavy, than if you were just using mild Loads. This depends on how much the Case Neck is being Resized and the Method used to do the Resizing. (Measurable.)

Choices:
Yes
No
Occasionally

Question:
Do you use Velocity as a PI? I'm reluctant to include this one because of the Totally WRONG concept that a person can actually tell what the Pressure of a Load is by Velocity alone. It CAN NOT be used as a Stand Alone PI because of all the variabilities in the Cartridge Components and Dimensional variations. But..., if a person was watching the Velocity and it was higher than expected, then the potential is there for something to be wrong. I do understand why people want to believe it is a PI, because if it did work all the time, Developing a SAFE MAX Load would be very simple. (Misleading)

Choices:
Yes
No
Occasionally

Question:
Do you use the MAX Loads shown in the various Manuals as your PI? Due to the variabilities of the Cartridge Components and firearm Dimensions, it is best to use the Loads listed in the Manuals simply as Guidelines, but some folks believe it is OK to just toss in a Load at MAX and go. (Guidelines)

Choices:
Yes
No
Occasionally
Nice to know what the Mfg used, but it is only a Guideline for me.

Question:
Do you use Case Head Expansion(CHE) or Groove Expansion as a PI? (Measurable)

Choices:
Yes
No
Occasionally

Question:
Do you use Pressure Ring Expansion(PRE) as a PI? (Measurable)

Choices:
Yes
No
Occasionally

Question:
Do you use a Haphazard Strain Gauge System as a PI? There have been a few discussions in the past on the usefulness of these non-calibrated, guessed at dimensions, fudge factored, extremely expensive, Lab Environment devices. (Misleading)

Choices:
Yes
No
Occasionally

Question:
You left out what I use as a PI!

If I did, it is an oversight and would appreciate you letting us know what you use.

Choices:
Yes, I use something different.
No, I think they are all covered(maybe).

 

Over pressure is not really an issue for me.
I read a lot about it in this forum and I always ask myself, why?

I have an interior ballistic program (QuickLoad) and a lot of reloading print media. Usually I double check what I'm doing (or am planning to do) with both. This way I come up with an absolute maximum for my tests. Doing so the worst I have seen were primers that were duely flattened. Never have I encountered loose primer pockets or brass flowing into the receiver, just to name a few.
Plus, my ammo is absolutely accurate and my game dead.
The only reason for my to really dig into this topic would be, if was to develop a wildcat.

So why is this of so much concern for the regular reloader? Do you always need (or want) to know the limits of your gun? And then, when you do know that, what do you do with it? Shoot max. loads? I'd rather not.

Might have been a good poll had you left out your own opinions. These will influence the results ans skew the results to fit your preconcieved ideas. I did vote but ignored your opinions.

Larry Gibson

we can have some good discussions later.....

I'm surprised at the number of folks using velocity as a pressure indicator.....bear in mind that the question did not ask about pressure gauges.....only indicators and like the others, I, too, voted affirmative as using velocity as an indicator.....but discussions later as we need a lot more feedback first.

It would be helpful if the author would remove all the attitude and bias from the wording of the poll questions. If the author then wants to take up the mantle of his attitudes and bias in the discussion that's fine with me. Otherwise, it just seems like an attempt to start arguments. But then again anyone is free to do what they want, including starting such a thread or not participating in it. Thanks.

You need one more...

All of the above. (almost)

I watch for ANY sign of pressure.

I made the mistake of not paying close enough to the little details and now I have some 338 brass that won't hold a primer tight enough.

Every primer gets looked at as it comes out of the chamber. (bolt lifting and ease of action are taken into account at this time also)

Necks are checked for sharp edges rather than sooth transitions. Also case is caressed for any case head bulge.

When back at the bench, when decapped (universal decapping die in seperate press) the tension of the primer coming out is noted.

Now into the walnut shell for a media swim for a few hours. Then we look over every thing again!

The primer pockets are cleaned with the uniformer and if ANY brass comes out, set it aside and take a better look.

Neck sizing is next and then to the calipers to make sure we aren't to long. If there is more than a little gain in length, it also gets set aside.


For the most part, I stay away from high pressure but if I get it I will know!

I just learn to stay away from hot loads, realizing that the extra 100 fps the hot load is gaining me, isn't anything that I can't live without...

I am pretty much a primer looker...

If a primer pocket can't hold up 5 times and be tight on the 6th, then the load's too hot for my personal use...

darn simple for me i stay within the guide lines and don't need the max plus loads, accuracy and first shot placement on game is much more importment then speed.

quote:

Over pressure is not really an issue for me.
I read a lot about it in this forum and I always ask myself, why?

I have keen interest in high pressure - I want to stay away from it! I am primer looker and I check for case length increase. I want zero increase. I had never heard of primer pocket shortening untill now. To me, high pressure is 45,000 CUP. I do load my hornet to max as defined by me. My 303 max is totally subjective. I look at the case and the primer and I 'feel' the pressure. Then I literally feel the recoil. Too sharp and too much is uncomfortable so I look for a balance between enough velocity and tolerable recoil. Besides, it's a 106 year old action!

I keep things simple. I only need one indicator, subjective or not, for me to stop adding powder. I've noticed that more often than not, I can get more powder into the case with the bullet seated at the lands than what is published in a manual as a max load.

The first sticky bolt throw, I back off the charge 1 grain, sometimes up to 2 grains and I'll retest if I'm really interested. I inspect all primers.

One other item I think could be considered an indicator is how dirty the neck is. The hotter the load, the less fouling on the external neck. I've noticed in a few rifles that sticky bolt lift has been coupled with very little to almost no outside neck fouling.

quote:

Over pressure is not really an issue for me. I read a lot about it in this forum and I always ask myself, why?

Good thought. I am not interested in "over-pressure" loads at all. I AM interested in getting top performance out of my cartridges and that sometimes takes exceeding the book values to attain. I don't suggest it to anyone else, it's just what I do.

The books are not gospel truth after all. The "book" loaders were using their rifle to develop their loads, they did not have mine to work with but I do. Therefore, I load up until I obtain NORMAL velocities OR see over pressure signs. If I need to, I'll change powders and continue to work until I get the performance I seek.

If I want more velocity I go to a difference rifle and cartridge, one that's made for what I want. Only a fool would attempt to load his 30-06 to .300WM velocity, or try to make a .358W out of a .35R. IMHO of course!

quote:

Originally posted by McFox:
...I have an interior ballistic program (QuickLoad) ...

Hey McFox, The "Computer Ballistics Programs" should have been in the list. Can't go back and change it now because it would re-set all the votes.

For those of you who do use them, feel free to mention it and we can do a mental tally on them.

if after using most of the mentioned pi's i don't get at least 10 loads from the vast majority of my cases without case failures i assume pressures are excessive with that lot of brass and reduce charges accordingly.

I use the majority of the listed signs and the appearance of one is in my mind cause for a second look at the others. There can be other causes then pressure for some of them though, and it is important not to jump on a symptom and declare a cause without study.
Funny thing is I use a "strain thingy" to quote HC, and still observe my brass for signs of trouble. Old habits die hard...........
The strain gage hasn`t let me go where I shouldn`t yet that I`m aware of, but neither did PRE and my chrony when I relied on them.

Good post Hot Core, I`m sure there are going to be some rehashing their methods and others learning something new.

Hey HC

Unless I missed it, you missed one, the shiny spot on the case head



usually occurs in conjunction with hard bolt lift.

Other than that a pretty good poll!

I found out I am in the majority on almost all. BTW, the correct answers are:

NO
NO
NO
YES
YES
NO
NO
YES
YES
NO (too old fashioned)
NO ( " " " )
NO (can't afford one yet)
YES

quote:

Do you use Primer "Flattening" at the corners as a PI? Depending on the Headspace, specific Lot/Mfg of the Primers this can be a PI or totally misleading. (Subjective)

A very subjective test I have done is to use a known softer primer ie a pistol primer. Of course this throws in a curveball as the primer intensity is now different! But allegedly not that different. Nevertheless, a basically not a very meaningfull test! It might indicate something if used in conjunction with a chrony - Oops! Sorry Hot Core!

I'm new to reloading as I've only been at it for 2 years. I load 9 rifles for accuracy using the manual minimums and work up to max in 1/2 grain increments. I then choose the best group and load it for that rifle. Every rifle that I load for is capable of taking the animals I hunt at the ranges I hunt at minimum load velocities so I don't concern myself with speed. I watch for bolt lift,and flattened primers ......So far no overpressure problems with my hand loads. The only pressure issue I've ever had was with factory Hornady loads which is why I got into hand loading to begin with. Those loads almost sheared the recoil lugs off the bolt. At the time I didn't know what pressure signs were.........Never even heard the term so when the bolt was hard to lift and the case heads were stretched I kept on shooting like an idiot. I was very lucky.

So far every rifle but one will shoot 1 MOA or better with TSX's and Barnes load data..........So I'm happy.

Robert

I did not answer the questions in the poll. While both interesting & commendable, it does not take into account those who shoot setups other than the typical bolt-action rig. (I know, I know...considering and listing possibilities for everything out there could go on forever... )

Understanding maximum loads in the Contender, for instance, requires one to be able to comprehend backthrust issues while taking into account such items as case head size, etc. -- and knowing in which cartridges primer flattening is an absolutely unreliable indicator.

Every firearm is a rule unto itself, and significant factors in one particular gun may be considered less reliable -- and less significant -- in another.

quote:

Originally posted by Ol` Joe:
...I use a "strain thingy" ...

Hey Ol` Joe, And I thought I knew you.

quote:

Originally posted by the never improved upon Woods:
...you missed one, the shiny spot on the case head...

Goooood Gosh The ancient old "Ejector Mark" on the Case Head trick. One of my favorite "Toooo Hot" PIs and it isn't on the list at all. Pitiful!

For the Beginners, if you see the Ejector Mark like in Woods fine flick, it is time to back-off the Load a bit. It is created by the Pressure causing the Case Head to "stretch or flow" slightly into the Ejector hole/slot. Then when the Bolt is rotated, the spot is either polished or some Brass can be sheared off depending on the strength of the Load. Just too Hot for that specific Lot of Cases.

quote:

Originally posted by Bobby Tomek:
...it does not take into account those who shoot setups other than the typical bolt-action rig.

Hey Bobby, What do you use as PIs? I'm as interested in the things I missed as the ones I managed to remember.

quote:

Originally posted by vapodog:
...I'm surprised at the number of folks using velocity as a pressure indicator...

Me too.

quote:

...I, too, voted affirmative as using velocity as an indicator...

The first thing I look for is bolt lift, second is primer flattening, and third how tight the pockets are. I allways check for expansion rings before I load cases, when I see a bit of a bright ring above the case head, I toss em.

I have a few rifles that do well with slightly over max listed charges, yet they have easy bolt lift, primers look fine, velocity is on par with max listed velocities, the primer pockets stay tight, and the cases can be loaded at least 8 times. May not be the best way, but it's always worked for me.

That said, I've seen rifles max out before reaching book maxes by showing some of the above.

I like to start a couple grains less than max listed loads and work up. My reasoning is that a large percentage of my handloads have always performed the best at near max loads.

Reloader

quote:

Originally posted by Hot Core:

quote:

Originally posted by vapodog:
...I'm surprised at the number of folks using velocity as a pressure indicator...

Me too.

quote:

...I, too, voted affirmative as using velocity as an indicator...

Not to hard to understand. Take an '06 with 180 gr bullets for instance; if you've chosen the correct components and are conducting a series of test loads with 1/2 gr powder increases when you hit 2700 fps a gr or two below what you have loaded then you know you are getting into high pressures for the '06. Thus velocity does not tell you what the pressure is but it is an indicator of pressure. It takes pressure to push a given bullet so fast. Most of us understand that.

Larry Gibson

I use most of the above. I use a Chrony. I use the books. Brass stretch is not such a good indicator sometimes because cases are different, brass is different. It can be useful though.

Start out 10% low. Work it up to best accuracy. If the chrony says it's close enough to useful speed then it's done. If the load is getting up to max and the chrony say it's slow then it's time to find out why. If the chrony says it's slow and there are no pressure signs (CHE/PRE/primer cratering-backout/sticky bolt/splits etc then moving much more slowly keep looking for groups to change, speed to change and all the pressure signs.

In practice I chicken out regardless of pressure signs with loads that go over anyone's max. I don't trust that because max in one book is higher by a grain or two than another book that the low one isn't right. Accuracy trumps speed every time for me.

A strain gauge setup is really the best, it's the only way you're going to get accurate pressure measurements our of a sporter rifle. The science behind them is proven and accepted, so there's no use arguing that they don't work. I'm too cheap to buy one and don't want to glue them to my rifles, so that's out for me.

Barring a strain gauge, using some common sense coupled with a chronograph and published load data from a reputable source is your best bet to stay out of trouble.

Sticky bolt lift and expanded primer pockets are certainly indications that you're running too much pressure, but beyond that they're pretty crude indicators.

The old CHE/PRE methods have been rightly discredited in modern times. They rely upon the false assumption that brass is going to deform in a known manner when subjected to the pressure of firing. That thinking doesn't stand up to analysis because the modulus of elasticity of the brass in each lot of brass cases hasn't been measured therefore there's no reference standard which makes any measurements you take from a fired case worthless for trying to extrapolate pressure. Also, even if the modulus of elasticity were known for each lot of brass, the method still wouldn't work because brass doesn't deform predictably over the pressure range modern firearms operate in, that's why the ballistics labs used the copper crusher method before strain gauges took over, copper is a much better medium for measuring firearms pressures than brass. In other words, the CHE/PRE methods are essentially worthless. One saving grace, however, is that modern rifles are hugely overbuilt so you're not likely to blow yourself up even if you are trying to rely upon a useless method of determining pressure like CHE/PRE. With most modern rifles you could also rely upon reading tea leaves and still not likely blow yourself up, and the results would be just as accurate as CHE/PRE, plus you'd get to drink the tea.

But then again Hot Core knows all this already, he was likely just missing his monthly argument on the subject and trolling for an argument with the loaded questions on his "poll".

I don't try to control pressure to protect the rifle but to protect the brass.

Even if the load is well under maximum when the case head is a sloppy fit in the chamber and produces a big step at the pressure ring I will reduce the pressure.
So one pressure checking feature I use is how sharp the step is at the pressure ring. That is just an eye ball technique. 6.5 Jap Arisaka and .303 Lee-Enfields have this problem.

Another pressure indicator I watch is the primer radius at the edge of the firing pin dent.
When that radius goes to a sharp corner you are getting close to piercing a primer or expanding the case heads in most rifles.

quote:

Another pressure indicator I watch is the primer radius at the edge of the firing pin dent.
When that radius goes to a sharp corner you are getting close to piercing a primer or expanding the case heads in most rifles.

I too want to protect my brass but I do have older and less strong rifles so I want to protect them too. (My Lee Enfield is 106 years old). As to the primer dent radius .... well, my hornet actually produces a crater. The dent is not very deep either. (I am using soft primers - Fed 205). I put the crater down to insufficient firing pin protrusion, leaving a gap between the pin and the hole. (Could that cause accuracy problems?) Beyond that, I have not previously looked too closely at the dent radius but I will be from now on - good tip!

quote:

So one pressure checking feature I use is how sharp the step is at the pressure ring. That is just an eye ball technique.

Me too!

quote:

I don't try to control pressure to protect the rifle but to protect the brass.

That makes the "old CHE/PRE method" valid!

quote:

Hot Core knows all this already, he was likely just missing his monthly argument on the subject and trolling for an argument with the loaded questions on his "poll".

Oh..! Oh...!

quote:

Originally posted by 303Guy:
...That makes the "old CHE/PRE method" valid! ...

Hey 303Guy, It does appear that a good number of people agree with you.

quote:

Originally posted by Bruz:
I load 9 rifles for accuracy using the manual minimums and work up to max in 1/2 grain increments.

Just a minute, what sort of cop-out is this.
What we want to know is. . . just how you determine your max.

Well no one's even mentioned my favourite "limit" (or rather "back off point" so I'll leave it till last.

So where to start. The feller that hoyes his brass because it has a shiney ring? jeepers I think all my brass has a shiney ring. Whenever I get to wondering, I cut the case open looking for the dreaded head seperating weak spot, and nothing. Never. Never ever.

I can easly induce a case head seperation if an action has excessive headspace, and I FLS once, twice, and crack it goes. Otherwise nada.

I marked primer appearance, as I see a correlation with increase in load, but depending on the primer,rifle ect. BUT, the only time I have seen primers fall out every shot was with factory loads. AND, what stumps me is that when I back off from flatened primers, they often seem to get flatter.

Cases lengthening doesn't do it for me as I think they actually shorten on fireing.

Anyway, the story is the brass is the weak link.
So, regardless of the fella that was worried about different brass, well it's still just brass isn't it?

I don't measure PRE or CHE because I don't have the tools, or the patience, and I never get the same measurement twice on anything.

Don't know that I've ever got heavy bolt lift, but I've seen others with it, and I don't want it.

So, knowing that cases do expand on fireing,
and eventually don't spring back so much with excess pressure, when nearing a max load I try to reinsert the just extracted case. When it becomes tight to chamber I back-off to the previous load as my max.

This seems to work for me as the bolt has some camming action to open, yet I have to supply the effort to close it.

And as the primer is only a little bitty bit of brass also, I've yet to see one that didn't show signs of pressure. In the long run, I also go back on loads if the primer pocket gets too loose too quick, but that's if i haven't already blown myself up I guess.

quote:

The feller that hoyes his brass because it has a shiney ring? jeepers

We've been saying shiney ring when we mean 'bright' ring. Even then it is not bright - just a bit more 'yellow' than the rest of the case.

quote:

... AND, what stumps me is that when I back off from flatened primers, they often seem to get flatter ...

Hey, I've had that! It might have something to do with powder compression/compaction. ??

quote:

Cases lengthening doesn't do it for me as I think they actually shorten on fireing.

I've found that too! (Doesn't seem to happen when loads are too hot 'though. )

quote:

Don't know that I've ever got heavy bolt lift, but I've seen others with it, and I don't want it.

Me too!

quote:

... I try to reinsert the just extracted case. When it becomes tight to chamber I back-off to the previous load as my max.

Yup! That's what I do. But I don't recall ever having to back off. I just decide when the primer is flattening enough and all the primers have the same degree of flattening. (I have backed off on primer flattening. In fact, my primary objective is to get consistant primer flattening - without squaring the edges).

In 2000 I rebarrelled a 1938 K. Kale Turkish Mauser [1898 type Mauser] from 8mm to .243. The rifle had no magazine follower, spring, or magazine bottom plate.
1) I worked up until the bolt was stiff. I pounded open the action.
2) I should have quit then, but I kept going and the bolt was stiff I pounded open the action. The primer pierced and fell out.
3) I should have quit then, but I kept going. I felt gas bouncing off the shooting bench and giving my face a breeze. The bolt was stiff I pounded open the action. The primer fell out. The extractor ripped off the rim. I pounded out the case with a cleaning rod.
4) I quit then and went home.


What does it all mean?
A well developed load is not one that has stiff bolts, primer piercing, primers falling out, or rim ripping off.
So when that stuff happens, quit. Then back off a safety margin on the powder charge. There is your useful load.

My hornet primers have the firing pin indentation like the first primer in the picture but with nowhere near the edge sharpening. Even with lower pressure loads, the indent is the same depth but without the little crater and some roundness and the edge. But then the outer edge of the primer is very rounded.

I didn't vote on this one. I was almost done and didn't answer all the questions so it disqualified my whole vote.
Anyway, Very interesting topic. Thanks, Hot Core.
I guess I tend to use the manual max as a guideline. I occasionally flirt with "over book max" loads, but not vary often. I pay attention to stiff bolt lift. If it feels harder than a low power load, I will pay attention. (Can someone define what is a hard lift, or stiff lift, BTW? I have never had to hammer an action open, nor even had to strain to open it, but sometimes it gets a little more "tight" to open.) I also pay a little attention to primer pocket expansion and case life. Most of my 30-06 brass gets used untill the neck splits, then I chuck it. My 6.5x55 brass hasn't split, but I loaded one test WAY over book max once (Max was 43.0 imr 4831, I loaded to over 47.0), so the primer pockets are a bit loose. I should probably throw them out, but I am not shooting a hot load now so they keep working. I also watch for stiffer recoil as a factor, but most of my load development is spent in the mid to hot range, and not the hot to extreme. All that to say I guess I stay pretty close the the books, or whatever is the most accurate in my rifles.
Good shooting,
Graham

From the poll -

quote:

Question:
Do you use a Haphazard Strain Gauge System as a PI? There have been a few discussions in the past on the usefulness of these non-calibrated, guessed at dimensions, fudge factored, extremely expensive, Lab Environment devices. (Misleading)

For what it's worth, an established maker of premium bullets, who publishes a loading manual, is known to use the Oehler strain gauge instrumentation system in its testing. Given the obsession of this company for quality in all its products and processes, it's a good bet they know what is, and is not, reliable pressure data.

When reading these often contentious threads about pressure and the excess of it, I'm reminded of an article written decades ago by a certain outspoken advocate of the 270 (who goes nameless here lest the already inflamed among us be driven to outright incendary disquisitions). It reads, in part, "If you do not get primer leaks or blown primers, if your cases do not stick, if the primer pockets do not open up with a few reloadings, if the case necks do not stretch unduly, then, no matter what the pressure-gun reading would be, that particular load with that particular combination of components is safe in your particular rifle. On the other side of the picture, if you get primer leaks, case stickage, short case life, then that particular combination of components is too hot for your particular rifle no matter what readings a pressure gauge would show."

I've believed for a long time that a handloader can't go very wrong if these precautions are observed. Now, I do not minimize the value of using additional methods. Several of HOTCORE's poll choices I use myself, case head expansion principally among them. But if a handloader heeds only the writer's advice above, he's unlikely to get into serious trouble.

meplat,
Communism works by confusing zero sum gain systems with open ended systems to trigger the feeling of being cheated out of a share.

These threads work by confusing public consumption load testing with individual rifle load testing, triggering a fear of over pressure.