quote:

Well, it looks like I was, how can I say this nicely, ...RIGHT AGAIN!!!

... You can see denton had to leave out something that "blew him out of the water", because there is nothing in "Mr. Water's words" that actually says PRE or CHE.

This is udoubtedly the most stupid of all possible Hot Core responses. Ken Waters' classic article on PRE doesn't mention PRE! Now that's FUNNY! Thank you Hot Core... I have something to laugh about for the whole rest of the week. You should have spent the $6 and bought a copy of the actual article, and read it. That's what I did.

Here are excerpts from Ken Waters' own words, in the order which they occur in the original article. The original document is readily available for anyone who wants to check it.

quote:

[Setting up the problem]

Ballistics laboratories utilize special pressure barrels and copper or lead crusher gauges—or, alternatively, electronic transducer strain gauges—to measure chamber pressure. Such systems, however require both costly equipment and skilled technicians, placing them beyond the reach of individual handloaders.

It is essential, therefore that we have a method of judging pressured developed by certain loads in certain firearms…

[Now proposing his solution]

I have agreed to explain in detail the system that I’ve been using… All that you need in the way of tools is a standard on-inch micrometer to measure case and bullet diameters, plus a dial caliper for measuring case and cartridge lengths..

[Managing expectations]

…and judging, rather that reading pressures, since any such method is far too inexact to qualify for any term such as reading that implies greater precision that is actually the case.

[Theory of operation]

The method that I use is based upon the fact that the chamber of any firearm, regardless of type, is slightly larger than the cartridges that are to be fired in it. Accordingly, the brass cartridge case has room to expand… With a good modern bolt-action rifle, the case or the primer usually fails before the rifle does.

[Exact instructions for doing the judging]

Judging pressures, as I go about it, calls for first firing several factory cartridges in the firearm… Once those cartridges have been fired, I measure the diameters to which their cases have expanded at the pressure ring… A micrometer…is used for this purpose…

On factory-load cases fired in the same gun, the diameters of the pressure rings may be much the same, or they may differ considerably…

Someone is sure to ask why I take measurements over the pressure ring rather than across the solid web of the base. There are at least four good reasons…

Once the expansion data are known for factory cartridges in my test gun, I am ready to start gathering comparative data from handloads. My procedure is as follows…

By systematically recording the diameters of pressure rings, I am able to tell whether my handloads are creating peak chamber pressures that are below, roughly equal to, or in excess of the pressures produced by the factory ammunition that I used as a basis for judging pressure…

It's all about PRE. It is the classic article everyone quotes. It is six pages of nothing but PRE.

Dumb move, Hot Core. Really, really dumb.

Hot core and Denton, Since you are both experts please answer this. I am currently trying to load for a 264 WM. 26" barrel. I have no pressure test equipment, other than a micrometer and a chronograph. There are lots of published loads for this round. I have 100 unfired Rem. brass, cci 250 primers, various bullets. When I work up to within 100 fps of published "max" velocities I get over .0005" belt expansion. Should I be measuring the belt or pressure ring? Should I fire the cases once before using the mic? Should I throw the mic away and just try for say 3100 fps (140gr) or 3300 (120gr)? This argument between you 2 has only furthered my confusion. Rick

Rick243,

I sure claim to be no expert. I always measure the head. I use that measurement along with velocity changes and other observations to try and determine a stopping point. From what I've seen when that primer lets go you are over 70 closer to 75,000.

Rem brass almost always gives me higher pressure for any powder charge.

Many rifles will never reach the max velocities printed. A long list of factors as to why not.

In MY OPINION if you are getting .0005 CHE then I feel you are to hot. Again my opinion and a couple $$ will buy you a cup of coffee.

If you resize so you headspace on the shoulder and then can get 3-4 loading without the primer pockets getting loose I would call it good.

I have never been in a situation where 100FPS made or broke the deal.

SAAMI specs for commercial 264 WM ammunition is 3300 fps for a 100 grain bullet, and 3015 fps for a 140 grain bullet. Sorry, they didnt specify the 120 grain, but a good estimate would be midway between the two values given.

Hodgdon does list an H870 load that is supposed to push a 140 grainer above 3100 fps (26" bbl). I have usually found their data to be among the best and most reliable...usually. I interviewed the Ron Reiber, the head of their lab, for an article, and I was impressed with how careful they are.

It's not a bad thing to watch the belt growth, but I think that your chronograph is going to be more useful to you. If you are using the book powder, bullet, and primer, it's a good idea to stop adding powder when you get to the published speed.

Chronographs don't measure pressure, but MV linearly tracks powder charge over a broad enough range.

I suggest that you prepare two cartridges at each of several loads, between what you think minimum and maximum are. Work up from the bottom, letting the barrel cool for a long time between shots. Graph your results as you go.

If you see pressure signs, stop and back down.
If you reach the published MV for the load, stop.
If you reach the maximum listed charge for that load, stop.
If the MV curve flattens significantly, stop and back down.

Whichever you hit first is going to indicate where your economical operating point is. That's all you need for 99% of cases. I happen to shoot some odd calibers. If not for that, I doubt that I would have worried about measuring pressure.

That cartridge is designed to run at up to 64,000 PSI, which is going to limit brass life in any event. It's an amazing cartridge, but economy wasn't its main design goal.

quote:

Originally posted by denton:

quote:

Well, it looks like I was, how can I say this nicely, ...RIGHT AGAIN!!!

... You can see denton had to leave out something that "blew him out of the water", because there is nothing in "Mr. Water's words" that actually says PRE or CHE.

This is udoubtedly the most stupid of all possible Hot Core responses. Ken Waters' classic article on PRE doesn't mention PRE! Now that's FUNNY! Thank you Hot Core... I have something to laugh about for the whole rest of the week. You should have spent the $6 and bought a copy of the actual article, and read it. That's what I did.....

If you all will simply look at what denton pulled from Mr. Waters article on the previous page, you will notice denton actually cut it out so Mr. Waters' actual mention of "PRE" is not there. The mention of PRE is what denton installed in his attempt to "define" what Mr. Waters actually said.

I don't doubt the article is about PRE since Mr. Waters championed the method for many years. Never disputed that. What I dispute is when denton goes in and "puts it in his words", which is unnecessary and skews the facts. But, you all should realize that by now.

Now that he has been shamed into printing it all out, the method should be clear and easy to understand "if" you get past denton's skewing.

Hey rick, It has already been posted that you were doing the right thing by stopping with 0.0003"-0.0004" CHE. And you mentioned the Velocities were too high if you go to 0.0005" CHE.

So, what are you confused about?
---

Hey Ol` Joe, I think the last time we got into a discussion concerning the TOTALLY WORTHLESS HSGS fiascos that I also asked you some questions which you "also" refused to answer. Fine by me, since I knew the answers before I ever asked.

Here it is again from page 1 just for you:

Hey Ol` Joe, Have you ever seen ANY of the Bullet or Powder Manuals "recommend" (the pretty much worthless) HSGS?!?!?!? Don't you find it interesting that both CHE and PRE are highly recommended by the Experts and no mention is made of wasting any money on a HSGS?

quote:

The mention of PRE is what denton installed in his attempt to "define" what Mr. Waters actually said.

Ken Waters defined what Ken Waters said. And what he wrote directly contradicts Hot Core, without any help at all from me.

Everyone sees what a fool Hot Core is. Bill Clinton and Yassir Arafat would be proud of their student.

Twist... spin.. deny... lie... accuse, accuse, accuse... divert attention. You've got the formula down pat.

Take Ol' Joe's advice and quit digging. It's embarrassing to see a grown man pee all over his shoes that way, and then insist that he did it because it improves the leather.

Rick,most data for the 264WM is older than you are,and derived from CUP method.The barrels have long ago burnt out.I think Accurate powder's data is current.For the 264,basicly your are going to have to buy your own gages.

The 264 cult meets at 24hr.campfire,do a search.

quote:

Hey Ol` Joe, Have you ever seen ANY of the Bullet or Powder Manuals "recommend" (the pretty much worthless) HSGS?!?!?!? Don't you find it interesting that both CHE and PRE are highly recommended by the Experts and no mention is made of wasting any money on a HSGS?

HC, Pg 5-7 & 5-8 in the Hodgdon #27. There is mention of useing a Oehler M43 along with the Copper Chrusher and Piezo systems. They DO recommend use of a referance load, SAAMI or factory ammo, be included in the test set up along with a cronograph when useing the M43 as they do when the other two systems are used. The chapter is titled "Pressure Measuring Techniques" and makes no mention of PRE, CHE or other systems you`ve discussed here.

The CHE system is mentioned on pg 5-1 through 5-6 under a heading of "Pressure" and is included in a discussion along with primer appearance, gas leakage, loose primer pockets, ejector marks, and other bright spots on the case head.

No where do I see them claim CHE as a "MEASURING" system as they seem to do with a strain system. I also don`t see either systems "recommended" as the system of preferance. They appear to OK the use of CHE along with other indicators to verify pressures are too high, although they do claim the strain system (M43) as allowing one to additionally "measure" the variations in pressure with component changes.

I`ve made my mind up as to which is more useful to me, as it seems you also did some years ago. I used PRE for quite some time and agree - this is twice now - it has some value but better has come along IMHO, I think we agreed on this the last time we discussed the subject.

You`ve argued with Denton and a half dozen others much more knowlegable then me on the subject. I`ve answered you with my opinion and acknowlegded it as such, and I`ve shown you the sources that I formed them on. If they don`t fit in with yours I`m sorry. I`ll let you continue your pissin` contest with the others without me as you seem more interested in that then adding anything of value to this subject.

This is a good place to relate experiances, tools, preferances, ect on a subject we all enjoy. The fact you disagree with on one method over another is not a crime, we all have beliefs others don`t agree with. The idea is to all have a word on what we know about the subject at hand and let the person posting the question come to his own conclusions.

Hey Ol` Joe, Thanks for the info. My last Hodgdon Manual is #26.

I think #27 was a 3-ring binder style like the old Sierra Manuals if I'm not mistaken. And that is why I never bothered getting it. Also mentioned it(being the 3-ring style) to the Hodgdon Rep at an NRA Convention and he said they intended to offer bound Manuals once again in the future. Now I see some "Yearly" large paperback Hodgdon Manuals, but haven't bought one of them either.

I'll flip through the #27 the next time I'm near one.

Best of luck to you.

quote:

Originally posted by denton:

quote:

How did CHE correlate with velocity?

IIRC, I did not take velocity data for these tests.

However, the correlation between velocity and strain gage measured peak pressure is very, very high. So, in effect, you can substitute velocity on the horizontal axes of the PRE and CHE graphs in the article, and the appearance of the graphs will change very little.

But what about those instances in which an increase in powder charge gives an increase in pressure, but a lower muzzle velocity? This is a common occurrence with some powders, such as WW 760........

I am not convinced that the CHE/PRE approaches can even reliably allow COMPARATIVE results, since if a particular load is put in a specific lot of new brass and fired in a pressure gun, individual rounds that show a higher measured pressure will often show LESS measurable case expansion than rounds that show lower measured pressure, with all other factors being as identical as it is humanly possible to make them.

To me, this entire debate is "a tempest in a teapot, full of sound and fury, SIGNIFYING NOTHING". Because, at the end, we are still left with nothing more concrete than our personal judgement upon which to decide if our loads are safe or not.

quote:

Originally posted by rick243:
Hot core and Denton, Since you are both experts please answer this. I am currently trying to load for a 264 WM. 26" barrel. I have no pressure test equipment, other than a micrometer and a chronograph. There are lots of published loads for this round. I have 100 unfired Rem. brass, cci 250 primers, various bullets. When I work up to within 100 fps of published "max" velocities I get over .0005" belt expansion. Should I be measuring the belt or pressure ring? Should I fire the cases once before using the mic? Should I throw the mic away and just try for say 3100 fps (140gr) or 3300 (120gr)? This argument between you 2 has only furthered my confusion. Rick

Actually, NONE OF THE ABOVE! Put away your micrometer-there are better uses for it. Select ten cases at random from that batch of once-fired brass. Reload these, noting if the primer pockets are still as tight as they were the first time you loaded the rounds. If they are, shoot them, and repeat this process. If you get to the point where you have fired these cases ten times and the primer pockets are still OK, that load is not too hot for your rifle! Now, my standard is TEN loadings-others may settle for four or five!

If, on the other hand, after the first shot the primer pockets have become noticeably less tight when you seat the new primers, the load is too hot and should be reduced by 5% and the process started over.

quote:

Originally posted by ramrod340:
Rick243,

I sure claim to be no expert. I always measure the head. I use that measurement along with velocity changes and other observations to try and determine a stopping point. From what I've seen when that primer lets go you are over 70 closer to 75,000.

Rem brass almost always gives me higher pressure for any powder charge.

Many rifles will never reach the max velocities printed. A long list of factors as to why not.

In MY OPINION if you are getting .0005 CHE then I feel you are to hot. Again my opinion and a couple $$ will buy you a cup of coffee.

If you resize so you headspace on the shoulder and then can get 3-4 loading without the primer pockets getting loose I would call it good.

I have never been in a situation where 100FPS made or broke the deal.

He said ".0005" BELT expansion" - this is NOT .0005" CHE!! Besides, .0005" is only HALF A THOUSANDTHS. This is miniscule expansion OF A BELT ON A BELTED MAGNUM CASE.

Boy, talk about how to win friends and influence people!

I figured this thread would get HC and Denton back at each others throuats, and avoided it as long as I could...

quote:

just check your Speer and Nosler Reloading Manuals. They still use good old CHE and PRE.

I don't have the Speer manual, but I have Nosler #4 and #5. I'll be damned if I can find any mention of PRE and CHE in them.

I do recall Joe Cullison mentioned the use of it in Nosler's labs, but not for final testing for published data. That leads me to believe that it is a quick check to get in the ballpark before meving to other, better (and probably more expensive and time consuming) methods.

Bottom line for anyone still reading this without a final opinion, PRE/CHE CAN keep the CONSERVATIVE reloader out of trouble IF they have a modern STRONG action rifle. For weaker actions, pistols, black powder, etc. you are well above dangerous levels in these types of situations before expansion occurs.

Advocating CHE/PRE without this disclaimer is dangerous, IMO, as there ane plenty of newbies reading things like this who can be misled by the 'experts' who read here.

CHR/PRE simply does not have the repeatability and resolution for anything else.

The same goes for using a chrono...you gotta put in the disclaimer that using it to check for max loads is only (somewhat) valid when using the exact same powder. It is easy for the newbie to read 'just load to max velocity in the manuals' and substitute 4895 for 4831...then try to push for the 4831 velocity and encounter steel rain!

I'm off my soap box for now...

El Deguello

Yes you are correct he states he is getting .0005 belt expansion.

As far as I can see my reference was to CHE expansion. As I also said it was MY OPINION. I've back away from .0005 CHE for years and will continue to do so.

Please feel free to load anyway you choose.

quote:

Originally posted by ramrod340:
El Deguello

Yes you are correct he states he is getting .0005 belt expansion.

As far as I can see my reference was to CHE expansion. As I also said it was MY OPINION. I've back away from .0005 CHE for years and will continue to do so.

Please feel free to load anyway you choose.

I agree with you that case head expansion is different from belt expansion, which is often quite large due to many oversize chambers in belted magnum calibers. I suspect that if you got .0005" expansion of the diameter of a case head, the primer poskets would be pretty loose.....

Eldeguello, the biggest problem with the primer pocket approach is that it is very sensitive to the size of the brass and chamber.

In a chamber with bench rest tolerances, and a rifle that supports the base of a well-fitting cartridge, you can run the pressure up well into the 70,000 psi range, and never have a problem.

Conversely, brass that has a bit of clearance at the base can show useless primer pockets even with one mild-pressure firing. At one time Norma was known for "soft brass" because the primer pockets did not hold. Turns out, the brass just had smaller base diameters.

When all the variables are known (brass composition, brass dimensions, chamber geometry, chamber dimensions, etc), brass deformation can give some good information. However, like with primer reading, there are simply many other factors that ALSO change brass dimensions (whichever one your favorite is). End result: you don't know which is which. Unless, of course, you already know everything.... JMO, Dutch.

quote:

However, the correlation between velocity and strain gage measured peak pressure is very, very high. So, in effect, you can substitute velocity on the horizontal axes of the PRE and CHE graphs in the article, and the appearance of the graphs will change very little.


But what about those instances in which an increase in powder charge gives an increase in pressure, but a lower muzzle velocity? This is a common occurrence with some powders, such as WW 760........

Yes, you are correct. That does happen. In that case, velocity is no longer linearly correlated with pressure. Good catch.

At one time I used CHE as a prime indicator of pressure and don't believe I was totally wrong. Problem is that I was only partially right.....and there's more to it.

Today I still measure it and don't get concerned until .0005 increase. Then I consider other things as well but keep shoveling in coal until .0005 is reached.

I think my prime indicator is the repriming phase.....is the primer pocket expanded beyond holding reasonably secure a new primer.....if so I've gone beyond the pressure limits of my system.

Looking at primer flatness is still a valid thing to do but is one of several indicators and stiff bolt opening, sticky extraction are still valid.

It's my feeling however that when I have these indicatore I'm WAY over the limits and myst not just roll back some powder but roll back a lot. More likely three grains instead of one.

Short of a pressure barrel it's still a scientific art at best and needs a practiced observer to test.

quote:

Select ten cases at random from that batch of once-fired brass. Reload these, noting if the primer pockets are still as tight as they were the first time you loaded the rounds. If they are, shoot them, and repeat this process. If you get to the point where you have fired these cases ten times and the primer pockets are still OK, that load is not too hot for your rifle! Now, my standard is TEN loadings-others may settle for four or five!

The latest Lyman Reloading Manual states that THREE reloadings before encountering loose primer pockets IS ACCEPTABLE.

You know, when I've read everything else interesting on the 5 or so shooting and fishing boards that I visit. I then read these strings on pressure measurement.

It's kind of like watching network evening TV. It occupies you without giving you any information that you can't immediately stop using to deal with something more important that comes up, like taking a pee or scratching your ass.

quote:

Originally posted by CDH:
...I don't have the Speer manual, but I have Nosler #4 and #5. I'll be damned if I can find any mention of PRE and CHE in them.

Hey CDH, I couldn't find it either and a buddy who reads this stuff but doesn't post told me to look on pages 35 & 36 in Nosler #3 and there is the method Joe Cullison and Nosler uses for PRE.

quote:

Bottom line for anyone still reading this without a final opinion, PRE/CHE CAN keep the CONSERVATIVE reloader out of trouble IF they have a modern STRONG action rifle. For weaker actions, pistols, black powder, etc. you are well above dangerous levels in these types of situations before expansion occurs.

I "half-way" agree with you.

In cartridges like a 38Spl, 35Rem, 45-70s in real old actions, CHE will not detect expansion until they are already beyond the Pressure where a Reloader needs to STOP.

The part I disagree with is that PRE will work on all cartridges when done in comparison to Factory Ammo, because the Pressure Ring will expand even at those lower Pressures. Easy enough to see for yourself if you have one of the older relatively low Pressure cartridges.

Between the two methods, I do prefer PRE, but also track CHE on my Load Data Sheets as well.
---

Still interested on how your re-crowned rifle ends up doing. Best of luck to you.

quote:

Originally posted by El Deguello:
A much better method, if you have no actual pressure measuring equipment, is the "case life" method. This essentially states that if you have a strong rifle with correct headspace, you can load your ammo so that you get about ten loadings (or more) from a lot of brass, and such loads are safe.
...

El Deguello, you are inoffensive, practical, and succinct.
I will have to research your posts.

quote:

Still interested on how your re-crowned rifle ends up doing. Best of luck to you.

HC, it is looking like a bedding problem. The old stuff was crumbling out when I poked at it with a pick, and the Mauser indexed screws that I faithfully returned to the same point (instead of fully snugging doen) held things loose. Drilling out the old bedding around the screw channels and tightening a full another half turn got me back to having a 3" gun...so now I need a weekend to do a full rebedding. Stay tuned.

And now back to our regularly scheduled argument...

quote:

Originally posted by CDH:
...HC, it is looking like a bedding problem. The old stuff was crumbling out when I poked at it with a pick, ...

Sounds like you found it to me. It was giving every indication of something being loose with the shifting groups. Good for you and best of luck with it. I'll see if I can bring this back into line with the thread(no offense to you intended).

Sure thought CDH's problem was Strain Gauge related. Maybe someone who had it before CDH bought it, totally hosed the bedding by trying to hide a Strain Gauge under the stock (denton?) and thus got the bedding all goofed up.
---

Hey Rick, If you are still out there wading through all this fun, in addition to using CHE and the Velocity, the method that "El D" and some of the others mentioned about seeing how many firings through the cases you can get, without the Primer Pockets loosening, is just an excellent way to go with your AI cases. You can even use it without a Micrometer or Chronograph. Only thing it takes is some "time" to gather the data, but that just gives a person another good reason to go to the Range.

denton,

Thanks, nice article.

I was unaware of your study until today, and I admit I'm disappointed with results that point to not being able to solve my temperature-velocity variations by using Hodgdon extreme powders. I don't disagree with them, however. I'm sure I shoot my barrels too hot, and have therefore completely abandoned RL-22 and IMR-4064 for very quickly increasing pressure signs on subsequent shots that I blamed on heat soaking the cartridge in the hot chamber.

FWIW, writer John Barsness also disputes the utility of case head measurements to determine high pressure. He favors a chronograph.

Jaywalker

Jaywalker....

Thank you.

I'm still puzzled by Hodgdon's Extreme powders. Put Varget in the right 308 load, and the change with temperature is nil. Put it in a 223, and it is very temperature sensitive.

Sometimes their magic works very, very well, and sometimes not at all.

I read Gary's article and examined the bullets. I'm still not sure what he did with the road kills and what relevance it has to the telephone books. (I think he shot the deer lengthwise through muscle and bone - but I don't shoot big-games animals that way). The best data he shows is how the various bullets hold together when shot into telephone books, and his results mirror what the manufacturers say about their solid or semi-sold bullets - indeed, generally speaking the more solid copper component to the bullet and the less lead, the more the bullets appear to hold together and not open up. This effect becomes maximum with the Barnes bullets that hardly open at all - that is, they act like little high speed arrows.

Nonetheless, I was impressed with the performance of the traditional Remington and Winchester bullets at holding together.

In my opinion, the Barnes X bullets are too tough - they hardly open up and are at risk of "penciling" or "arrowing" an animal. This, indeed, happen with super tough a bullet. In my hunting family we have considerable experience with NPTs "penciling" on chest-shot elk - yes ELK! It doesn't take a rocket scientist to understand why this can happen when used on a large deer.

If you shoot an elk, deer, antelope, moose, big bear, whatever through the thorax - that is, your typical or average chest shot - the bullet will travel through the following structures:

1. Skin & hair - ~1/2 to 3/4 inches thick (not much and all soft-tissues).

2. Rib cage - 3/4 to 1.5" inches thick (not much). The rib cage is ~50% rib bone and ~50% muscle, and the bullet has about a 50/50 chance of hitting a rib bone or passing clean through hitting muscle only. If the bullet passes between ribs, there's been very little to start expansion - even for a NBT, let alone a solid or semi-solid bullet of some type (i.e., NPT or TSX). Even if the bullet hits a thin frangible rib bone, which are mostly hollow and filled with cancellous bone and marrow, there is little to start bullet expansion - but admittedly more than an inch or two of pure, inter-rib soft tissues.

3. Lungs - lungs are air-filled, friable tissues built much like very soft sponge. - ~80% air - yes, just AIR! Admixed are blood, pulmonary vessels, and elements of the tracheobronchial tree – thankfully, the vessels are there to be torn causing massive internal bleeding.

4. If you’re lucky (especially at long range) you'll hit heart and/or the great vessels entering and exiting the heart and lungs. Again, these are very friable thin-walled organ structures, which when hit, even with a bullet fragment will be devastated.

5. Also, if you're really lucky (again especially when shooting long range) you'll hit the vertebral/spinal column. This is stoutest structure in the thorax, and very vulnerable. If you hit with a bullet fragment -even the size of a 22 rim fire bullet - the animal is going down. It's like a brain shot – that is, the animal is going down from the shock and subsequently from any meningeal bleeding (dural hematoma). The animal is going nowhere, if it can’t move it’s legs.

6. The opposite rib cage - but WHO CARES if you hit the opposite rib cage. You're not going to kill the animal by puncturing the opposite rib cage. If the bullet hasn't done significant damage by the time it hits the opposite rib cage, you’re going to track that animal a long time with possible wastage.

Trust me guys, I know what the internal organ structure is of a large mammal, and there isn’t much in the thorax to cause bullet expansion. A bullet that doesn't open up fairly easily can quickly "pencil" an animal shot in the chest – including any sized North American mammal. The effect can be much like being shot with an arrow.

Don't get me wrong, arrows and "solid" bullets will kill; but, I want my bullets to open up and expend all that kinetic energy within the thorax. I prize accuracy, and I hit my animals in the chest (where most hunters hit their animals), even at 400 yds. plus ranges. I take pride in not gut-shooting animals.

My experience with the NBT is that they're just about ideal for killing North American big-game mammals with chest shots. The NBT is plenty tough enough, yet it will open up and kill quickly and humanely. (NBTs will penetrate bone effectively as well.) I've experienced NO bullet failures with the NBT. Animals from the size of prairie dogs to large bull elk drop in their tracks when hit in the "vitals" – miss the vitals and you got problems with any bullet.

quote:

Maybe someone who had it before CDH bought it, totally hosed the bedding by trying to hide a Strain Gauge under the stock (denton?) and thus got the bedding all goofed up.

Ho-hum. That would be Hot Core Fabrication 1.1 on the standard list, again. He thinks my half inch groups would be better if I had not installed strain gages.

quote:

Sure thought CDH's problem was Strain Gauge related. Maybe someone who had it before CDH bought it, totally hosed the bedding by trying to hide a Strain Gauge under the stock (denton?) and thus got the bedding all goofed up.

I can very safely say it was not strain gauge related. It appears to be age related, coupled with probably less than premuim materials related. Of course, who knows how many people have owned this rifle before I got it about 10 years ago...it's only about 97 years old.

Denton, your comment about HC..."He also favored us with his theory that the Speer and Nosler manuals recommend PRE/CHE. But then nobody could find those references" is not 100% true. On page 53 of the the 13th Speer Reloading Manual (Jan '03) there is an extensive discussion of HOW SPEER USES CHE in some situations. Moreover, the 48th Edition of the Lyman Reloading Handbook essentially endorces CHE (see page 99 from article by Bryce M. Towsley entitled "The Mystery of Pressure). Denton, it takes two to argue and you're one of those two.

If you compare the case head expansion of your handloads with the case head expansion of factory ammo with the same cases and bullets in the same rifle, you'll have a decent idea how much is enough. Manufacturers of factory ammo are quite competitive in the velocity department, and they push the envelope to its safe limits.

quote:

Originally posted by Ackley Improved User:
Denton, your comment about HC..."He also favored us with his theory that the Speer and Nosler manuals recommend PRE/CHE. But then nobody could find those references" is not 100% true. On page 53 of the the 13th Speer Reloading Manual (Jan '03) there is an extensive discussion of HOW SPEER USES CHE in some situations. Moreover, the 48th Edition of the Lyman Reloading Handbook essentially endorces CHE (see page 99 from article by Bryce M. Towsley entitled "The Mystery of Pressure). Denton, it takes two to argue and you're one of those two.

The Hornady manual fifth edition, page 23 states: If the case head is miked, it may show expansion- and even half of one thousandth of an inch (.0005) increase in the diameter of the case head is an indication of high pressure.

Their wording...."an indication" is in context of many other pressure signs and they did not say that it is definite proof of high pressure.

One may read these statements out of context and make erroneous assessments. In and of itself CHE is not anything but a piece of evidence to be used in context with an assorted list of other data readily observable to a trained reloader.

quote:

On page 53 of the the 13th Speer Reloading Manual (Jan '03) there is an extensive discussion of HOW SPEER USES CHE in some situations.

Then I stand corrected. Thank you for pointing this out. I've decided my whole second paragraph was a little mean-spirited, and have deleted it.

Yes, I have read the article in the Lyman manual. It says that the old timers did surprisingly well with PRE and other methods, but that they have long since abandoned them in favor of more precise methods.

Speer also started out with CHE, but also abandoned it in favor of better methods.

It's a reasonable guess that the same thing happened at Nosler.

I've never said that the method doesn't work. What I've said is that it doesn't work very well, produces only relative rather than calibrated results, and is occasionally dangerous. In fact, I've pointed out and published the errors in all the common methods, PRE/CHE, CUP, piezo, and strain gage.

Where I get off the train is when people start saying that it is "completely repeatable and reliable", "calibrated", or "the best system ever devised". All those are manifestly untrue. It is a mediocre, relative system with poor repeatability, as measured with accepted industry tools for evaluating repeatability.

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Their wording...."an indication" is in context of many other pressure signs and they did not say that it is definite proof of high pressure.

One may read these statements out of context and make erroneous assessments. In and of itself CHE is not anything but a piece of evidence to be used in context with an assorted list of other data readily observable to a trained reloader.

I have no problem at all with that statement. I think it hits just about the right balance.

I doubt CHE is as BAD as your article would suggest. If as Lyman indicates that manuals prepared with CHE provided reliable information and accurately predicted subsequent piezo PSI data, then CHE is a REASONABLE substitute for piezo data when the latter is not available. Piezo data is not available to ~99% of reloaders in this country, yet accurate micrometers and CHE measurements are.

My interpretation of Lyman is that CHE works fine, except for when it doesn't. "...it was discovered that most of the old data was correct." So apparently, some of it wasn't. And they found this out in the course of abandoning CHE in favor of the CUP system, which they obviously regard as better.

As to how good or bad the CHE system is, my article says what the data told me, no more, no less. I have no agenda, other than to find and report the facts.

Physics obeys everyone equally. Do an experiment if you like. If you do a careful job, and get results contrary to mine, I will be happy to see them, and to commend you for your good work.

Denton, to do the experiment right, one needs access to peizo PSI data. Sorry, but I don't trust your strain gauge system - you don't publish or use known internal controls. Even the piezo PSI folks test or calibrate with KNOWN internal controls.

Do you have financial interests in these strain gauge systems?

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Do you have financial interests in these strain gauge systems?

No. Cheap shot, by the way.

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Denton, to do the experiment right, one needs access to peizo PSI data. Sorry, but I don't trust your strain gauge system - you don't publish or use known internal controls.

True only if you are testing for bias. Testing for repeatability requires only that you compare the test object against itself, which is what I have done.

If you can get repeatability, you can solve the other measurement problems. Without repeatability, all else is lost. CHE has poor repeatability.

I do this stuff professionally. If you want the text references, I have many of them about 2 feet behind me, and will be happy to supply you with places you can check my statements.