I would think that not 1 person in several 100 that has a mircometer can use it with enough accuracy and precision (they aren't the same) to be able to use one to gauge pressure.....brass varies in hardness, chambers differ greatly, etc etc etc. Using a micrometer requires instruction, practice and experience when you get to the level of expertise required.

Remember it isn't what you don't know that will hurt you, it's what you think you know and don't that will bite you in the butt.

So enlighten me. How do you check? I keep reading this but am unsure just where to measure.

Bill Mc

Oehler sells a chronograph that has a strain gauge input that will give you pressure readings.

An oscilloscope can do the same thing, and you might be able to pick up a used one cheaper than Oehler's setup. You'll need to do a little more work getting the readings to be accurate, but oscilloscope text books often have a section on pressure readings from very fast impulses.

The strain guages themselves are dirt cheap.

I really want to try turning a cheap Mauser or Enfield into a dedicated pressure gun. It seems as if a $50 gun could be re-barrelled cheap enough for a caliber of interest and fixed up with a strain guage or piezoelectric transducer. For that matter, setting it up as a copper crusher doesn't seem too big a project for someone with the mechanical skills and time to do things like that. If all the gun was used for was pressure testing, you could ignore all the work invovled in getting the rifle to feed from the magazine, opening up the ejection port, all that.

Any suggestions for which rifle is easiest to rebarrel/headspace?

I'll report back if I ever end up with enough time and ambition concurrently.

DB Bill,

It is for sure that you have to use these measuring tools in order to get reliable measurements with them. I studied physics and did enough lab work to undertstand the difference between accuracy in a measurement and the precision of that measurement. Then I spent enough mechanical shop time learning how to do it.

Micrometer technique definitely matters and I don't know any other way to learn it than by doing it. You have to get the feel in your fingers to be able to take repeatable measurements.

jim dodd

------------------
"if you are to busy to
hunt, you are too busy."

[This message has been edited by HunterJim (edited 12-25-2001).]

Ditto on the stuff about brass being different. No two rounds are the same hardness, composition, etc. and that is what you are measuring. A chrony is more useful than a mic, and without a pressure bbl. or strain guage one is guessing.

The argument about using case head expansion measurements can get pretty intense because there are a lot of folks out there that really believe in it. I'm definately NOT one of them. This method is outlined in speer's reloading manual which to me is an endorsement of fundamentally bad science, but to some folks anything that is printed in a reloading manual is akin to the bible.

This method follows the same line of reasoning as the copper crusher method that ammo makers used for years and years to pressure test ammo. Basically a copper disc was inserted into a hole drilled into the chamber area of a pressure barrel then the load fired. The amount of pressure could be calculated based upon the distortion of the disc because other copper discs from the same lot had been tested to calibrate for comparison. Somewhere, someone along the line decided you could do the same thing by measuring the distortion of the case head after firing, the reasoning being that if it works with a copper crusher disc then it should work just as well with a brass disc (the case head). The problems with this are that copper deforms at a lower pressure than brass and the brass case head has no standard to compare it to like the calibrated lots of copper discs. Also, brass properties vary between lots. Any first year high school science student can tell you that an experiement means nothing without a standard to compare it to, so measuring brass case heads means nothing to a reloader because you're not comparing it to any known standard. That's why this method is junk science and should not be promoted by a reloading company like speer.

Most modern ballisticians will tell you that the case head expansion method is based upon faulty reasoning, but you can't tell that to some people and they'll defend it to their dying day. Heck, I guess some folks still think the world is flat.

Jim....my point exactly! Just telling a new reloader to go and buy a micrometer and measure head expansion to check for pressure isn't going to do it.

Let me quote something I just read by Mic McPherson..."simply measuring case head expansion will not tell the reloader how much pressure his load generates---not even in any relative manner. Furthermore, each reloading and firing cycle, where pressure is sufficient to produce permanent case head expansion, will result in a concomitant cae head hardening so that further expansion, with loads generating the same peak pressure, will eventually cease."

He continues that "variations in case head hardness are rather significant. Differences
between brands and within brands (lot-to-lot) often exceed 20 percent"

He also mentions a batch of Rem .350 Magnum brass cases tested that showed NO PERMANENT CASE EXPANSION when used with loads generating 95,000 psi.

The only way to be safe is....if you want .300 WinMag velocity, buy a .300 WinMag...don't try to get it with a .30/06. etc etc etc

You all be careful now "ya hear".

I just got strain gauges for all my rifles, and the peak reading strain gauge meter... total cost for software, 5 strain gauges, and the meter was $230. Don't know why anyone would rely on older methods, when there is a first rate way to do it that is so reasonable.

See www.fabriquescientific.com for info.

While the grandkids are celebrating Christmas, I'm going to carve out a slight bit of space between the barrel and forestock, and slap a gauge on my .308, in prep for a trip to the indoor range... then my Swede... and my Turkington... and...

Hey DB Bill, I see you are still trying to convince yourself that you didn't waste the money spent on your M43. Best of luck to you.

As for me, I'll stick with the good old dependable, reliable and 100% SAFE data collected with my 0.0001" capable Micrometers by measuring "both" the Casehead and Pressure Ring Expansion.

Let's see now, reloaders have been using Micrometers to verify Pressure levels ever since "Loaded Cartridges" came on the market. So, I guess the method just hasn't been around long enough to justify how well the method works. HAHAHAHAHAHAHA

Merry Christmas to all you guys!!!

------------------
Good hunting and clean 1-shot kills, Hot Core

I use my case head mesurements in concert with my chronograph data, but I don't think I am measuring pressure with my technique. Instead I am comparing the load under test with either other loads I hve developed, or with factory loads.

I standardized on WW brass long ago, and I use it unless there is no option. I use new brass or once fired brass to collect pressure indication with the micrometer. Over the years I have settled on using the fired case head size as my indicator of a safe load. For instance with the .30-'06 head size case I won't go over a final head measurement of .4700".

I also graph the behavior of chronograph data versus charge weight. I have developed a three axis graph. I plot charge weight along the horizontal axis, and final case size on the left vertical axis and instrumental velocity on the right veretical axis. That lets me look at load behavior in two ways together.

I would also be interested in the sources of the expert's opinions on what is good, bad and indifferent in reloading practice -- especially the estimation of pressure.

jim dodd

------------------
"if you are to busy to
hunt, you are too busy."

Denton

I would be real interested, and I think alot of others would be too , if you would post your experiences and impressions using your new pressure equipment after you have had a chance to wring it out . The price of that eqipment is well within the reach of just about any serious reloader .

As far as the M-43 goes , getting the best is never a mistake if you can afford the price .

I still find it amazing that people will think a 20 cent cartridge case is a precision pressure gauge .

Hot Core....nope, don't own a M43. I've never felt the need to try and reach absolute safe max velocity/pressures in any of my rifles...my purpose has always been to make accurate loads that don't stress my rifles or abuse my brass.....I have always figured that if I needed more performance I should go to a bigger case or longer barrel but then I've never felt that wringing the last 100 fps possible was really worth the extra risk involved.

DB Bill,

I agree with you that it better to move up to a larger cartridge case than it is to try and flog a few fps more out of what you can tell is too small a case.

I took a look at the strain gauge unit web page. I haven't poked around internal ballistics equations since I was studying thermodynamics and fluid flow in college. I notice that the author makes as many simplifying assumptions as he can to get an equation that he could solve analytically -- shoot we all do that. His methods are based on one or another model of the real world, just as we do with measuring cases after firing. He does note that he doesn't have a good way to perform an absolute calibration of the device.

I will be interested to read some results.

jim dodd

------------------
"if you are to busy to
hunt, you are too busy."

Hey DB Bill, Good for you. Hate to see anyone waste $2000 on the M43 and the Laptop to make it run in a non-Lab environment. No doubt they are excellent tools for a Lab though, once you get them calibrated.

I had the impression from a long ago thread that you'd purchased one. I must have confused that somehow.

Have you tried using Case Head and Pressure Ring Expansion? If so, which part did you have problems with? Maybe one of us can help you get the bugs ironed out if you are interested.

I agree there are some minor tricks to using the Micrometers. There is also a limited amount of tests you can perform on a "set" of cases before the data becomes questionable due to "work-hardening". And it is a good idea to keep good accurate records of the information you collect for a specific chamber and sets of cases.

A couple of years ago I was emailing a fellow(one of sdgunslinger's Heros, so he will remain nameless so as not to embarrass either of them) who was trying to correlate CHE/PRE with a M43. Even sent him some information I had on all the "tricks" I knew about getting the best results.

He just kept having troubles with the data. Well, after about 9 months or so it finally dawned on me that he was "still" Neck Sizing.

The method simply doesn't work properly for the PRE portion when Neck Sizing is utilized and was mentioned in what I sent him. I really don't think he ever understand that the Pressure Ring needed to be "realigned" so the next firing would have some significance.

Not sure he had a clue as to why that was needed. But of course that was not a trick, it was simply a basic understanding of how the method works.

Great method which works well. Always has - always will.

------------------
Good hunting and clean 1-shot kills, Hot Core

Hot Core....not a case of not knowing how to use a mic, just a case of what it can tell you...I think it is much to fallible to be used with any realibilty. Same reason I don't trust safeties.

<<He also mentions a batch of Rem .350 Magnum brass cases tested that showed NO PERMANENT CASE EXPANSION when used with loads generating 95,000 psi.>>

I needed a good chuckle this eve- found it! Kinda like the guy at the scene of a wreck talking about the chrome on the bumpers- "hey not a scratch". Thanks- that one's a good chuckle.

aladin....in a pressure gun under controlled conditions.

Hey DB Bill, So you've not even tried it.

I've found that to be the situation with most of the folks who "claim" CHE/PRE doesn't work. It REALLY surprises me that you would be commenting so negatively on something where you have no "1st Hand Experience". Seems out of character for you.

I still don't have a problem when people speak on subjects about which they know nothing, but it does seem appropriate to mention those thoughts are pure speculation on their part. Darn shame, cause I'd built up some confidence in your posts.

Such is life.

So folks, be sure to find out if a person really knows what he's talking about(aka 1st Hand Experience, proper educational background, an Open Mind and is blessed with good common sense) before you place a lot of faith in their posts.

------------------
Good hunting and clean 1-shot kills, Hot Core

OK, so much for the discussion. As I said in the begining, enlighten me.

So assume that I want to try this method of measurement and that I have and can use a micrometer.

Also know that I will do this only to see if there is any significant change in a case and the I will not exceed any saftey standards.

With that said, where do you measure on the case? Where do you measure on a belted case?

thanks
Bill Mc

Found this site.

Bill Mc

http://www.ammoloading.com/new_page_27.htm

DB Bill: I'd like to see that data. I question the carrying out of any test at those pressures. For sure the gun had to be remotely fired.

Hot Core.....First let me say I find your last post more than a bit offensive and your attempt to denigrate my posts just because they dont' agree with yours doesn't do much for my opinion of you either.

That little bit of "bitch slapping" out of the way, you continue to misunderstand what I am trying to say so let me try one last time. (1) I have the training and skill to properly use a micrometer to accurately measure expansion on something as soft as most brass, and (2) I have done it on many occassions BUT and it's a BIG BUT, I don't believe the results really tell me anything because of all the variables involved.

One last try at an example. Most will tell you to measure a factory round in you rifle both before and after you fire it and to take the increase in diameter at the expansion head as something you don't want to exceed..OK so far. As a reloader we have several choices..(a) we can use that same piece of once-fired brass and reload it and then fire it and remeasure and see how much it has expanded...my problem with this is the brass is now harder than it was the first time and in effect we aren't really measuring the same "brass"....or (b) we buy some new brass and measure that before and after firing and then compare it to the expansion of the factory found we measured but again we are looking at brass that may or may not be of the same "hardness" so what have we really determined.

Will measuring all this tell you something....sure it will say something about pressures but is it enough and is it repeatable? My answer is "not really anything" that I feel comfortable with enough to rely on in an objective manner.

P.S. I guess I should really know better than to try and convince people about this but ......

aladin....Mic McPherson is a well-repsected writer on ballistics and other matters related to firearms....he is a columnist for Precision Shooting & for The Accurate Rifle magazines, a consultant to the firearms industry etc etc etc and a fellow who is so damn sharp about reloading and internal ballistics it makes me feel like a two-year old at times so when Mic says something I believe it.

Hey DB Bill, Simply drew a conclusion from your "lack of a response" to my question to you and my offer of help. So, since you claim to be offended at my response - TO BAD!

Hey Bill Mc, I'll get a File out to you this evening concerning the techniques of how to go about being able to use CHE/PRE so it will help you when developing a Load.

There are a few things to watch out for, one of which is the "Work Hardening" of the set of Cases being used when developing the Loads. So, even though DB Bill does recognize that "concern" there is a simple way to address it which is covered in the File I'll send you.

The File is in Microsoft Word and the Data Sheet is in Excel. Most folks have no problem at all opening them, but let me know if you have a problem.

By the way, I should mention that I always encourage EVERYONE to use as many Pressure Detection methods as they have at their disposal. If you have a chronograph, don't count on it alone, but use it in conjunction with all the other methods, because there are situations where it can be misleading.

Edit: Just went to look at the page you have in your last post and it has an error on it concerning Full Length Resizing. The writer (OKShooter) mentiones having Case Head separations after Full Length Resizing the cases 5 times. The "impression left for the reader" is that the problem will only be corrected by Neck Sizing. That is misleading. If Full Length Sizing Die is adjusted so that it Partial-Full Length Resizes, you will get excellent Case life and the "potential" for improved accuracy over simply Neck Sizing.

However, regular Full Length Resizing (where some small amount of Headspace is created) has it's place in Dangerous Game Rifles and some Semi-Autos.

------------------
Good hunting and clean 1-shot kills, Hot Core

[This message has been edited by Hot Core (edited 12-27-2001).]

Subject: Pressure Reading - Belted Cases

From Ken Waters:

"Mic cases forward of the belt utilizing the "flats" of your dial indicator. Once the mean expansion of a factory load is known you have a norm against which to compare the expansion of subsequent handloads. An additional expansion of .0006 to .0007 ( I use .001 ) over the norm would be about average."

"Example: Normal expansion in the .300 Win Mag may be .5135" in an average chamber. Any handload that reads .5142 would be considered excessive regardless of the possible absence of other "signs" of pressure."

"I like to "neck size only" and fire a few cases to check this all out so that initial .5135" reading remains unchanged until the second firing takes place, eliminating the changes in case dimensions resulting from full length sizing. If it is O.K. after this check you know for sure it's safe with FLS cases. An expansion of .0035 above an unfired case often places you in close proximity to a maximum load in your particular rifle with your particular components. This is really all one can ask of a manual system, where the employment of sophisticated and expensiive testing equipment is out of the question. This system, in tandem with quality Chronograph data, is surprisingly useful and repeatable.
Supposedly, this .5135 / .5142 scenario is reliable. At .5143 you might get a bolt stick to some degree so obviously you back off within the guidelines."
_____________________________________________

For what it's worth:

Nickudu;
In my experience, however, with my rifles, this .5135" is already plenty warm. I have found that .5120" to .5130" is a "max" that can be reached before other serious signals of high pressure show up. This same technique can be applied to any case for which you have been able to establish a mean or normal expansion. Also, Remington & Federal cases are (were)"softer" than the Winchester stuff, generally. Not weaker but more ductile, often allowing a bit more leeway in the readings without coincidental pressure signs. You get a feel for the different brands after a while but the basics remain the same.
Another factor here is that I am unconcerned about getting many reloadings out of my brass so I push it hard and usually feel some loosening of some of the primer pockets as early as the 3rd firing which is when I chuck the cases out anyway. Other than regulated barrels on doubles (which preclude us from overloading anyway) I can not see that I wish to hunt anything, anywhere with 3 or 4 times fired brass, whatever the cost. Especially in regard to "dangerous game". 1x fired brass is the only way to go. Firstly, one knows it has integrity because you've already fired it once and one also knows it's not "overworked" and has dome his part to ensure there are no problems. The presumption of continued use of organized lots of the same brands of brass, powder and primers also contribute greatly to assessing the value of the comparative measurement data.

Instead of the link noted in a previous post, try this one:

http://www.ammoloading.com/new_page_63.htm

Nickudu....I think the operative phase here is "in an average size chamber". How can someone tell if they have an average size chamber? If it is a bigger than average you will get more expansion and if it smaller you will get less, right? So what can you then infer if you don't if your chamber is big, average or small? Suppose you have a chamber cut to minimum specs in a custom rifle?

If you are feeling the primer pockets loosen as early as the 3rd firing you are without a doubt pushing it pretty hard...why not just move up to a bigger case? This isn't a slam
but personally I've never seen the advantage to really pounding the brass like this as it also pounds the rifle's action and remember that at that level of pressure it only takes a small difference in the way you assemble a load to really spike the pressure and I would really hate to try and pound a bolt open "up close and personal" to something big and/or dangerous.

Hi DB Bill, Happy New Year!

It is my belief that irregardless of whether your chamber varies from another (which it almost certainly does) you are still achieving the required baseline data via the firing of the factory rounds in your rifle and these readings still provide you the factory expansion guideline for YOUR chamber. You would proceed accordingly. As I mentioned, the guideline presented By Mr, Waters was somewhat higher than that of my own rifles. I still agree with him, however, as to the indicated or self-imposed threshold of +.0035" above the factory round micrometer reading, taken at the expansion ring. In actuality, this system works even more reliably with the belted magnum cases, as one can butt his mic firmly against the belt, assuring a consistent positioning of the expansion ring within the faces of his micrometer. As to your point of "why push the envelope" and why not simply move up to a larger cartridge: When I began using this system few factory case options existed, for one thing, but primarily, I simply don't consider it "pushing too hard" if I should detect some loosening of primer seating tension in some of the cases after 3 or 4 firings, as this occurs to a similar degree anyway, even while using just "warm" loads. Heck, I find quite a variance in primer pocket seating tension using unfired brass, let alone brass 2x or 3x fired. I relegate 3x fired brass to load development only or discard it, regardless of primer pocket tension. I load for maximum hunting performance and there's no doubt in my mind I'd do the same thing if I did move up to a larger case. The burning a lot more powder in the larger cases only to gain a few hundred additional FPS, maybe, is counter to my preferences as to both hunting rifle design and attendant shootability. I am speaking of longrange performance here and make this distinction because heavy calibers and dangerous game encompass other considerations.

Nickudu....a gentlemanly post and a Happy New Year back to you. I'm afraid I'm just a little too "anal" for your methods. I keep brass seperate by the number of times it's been fired and before I even think about reloading it I prep it if the brass needs it. I uniform the primer pocket, I deburr the inside of the flash-hole and I check the necks for consistency of thickness and if they vary too much I turn them until they are consistent as I believe uniform neck tension is one of the more important things for consistent performance. I seat all my primers one at a time by hand and if any doesn't feel right I mark it and the case goes into the pile of brass I use for "foulers". I also anneal my brass no more than every 5th firing (the time I expend on getting good brass requires it and remember I do a lot of shooting with my Lazzeroni brass which approaches $2 each). After sizing etc I check the brass for run-out and after charge it with powder and seat a bullet I check it again for run-out...now I don't do every case or loaded round but I do enough for quality control. I throw my powder charges but do weigh every 5th one and if I find a problem I go back four and weigh each of them. I do this for every load I shoot as I always want to make sure that any problems are with my shooting technique and not my ammunition. The secret to making all this easy is good equipment and to me the most important is a good set of in-line dies for each of my calibers..they allow me to either just neck size or to bump the shoulder and with different inserts I can adjust neck tension with ease. Is this kind of precision necessary for a good shooting rifle...of course not but it is very satisfying and a few hours in my reloading room does seem to keep my from putting my hands around the necks of the many idiots I meet in my profession. Cheapest therapy around.

I've been using my runout comparitor to measure pressure ring expansion. It doesn't tell me what the pressure is but it darned sure points out soft cases that need to be loaded a bit less vigorously. First I fire a box of factory loads and take the average expansion. Then I full length resize and measure the expansion caused by my load. I stop when the average equals the factory load. Now when I get some virgin brass, and load it I know when to stop, regardless of the amount of powder it takes to reach that same average expansion. The comparitor takes the proper "feel" of good mike readings out of the equation. I believe any measurabe case head expansion indicates short case life due to loosening primer pockets. I don't go there.

DB Bill,
Yes, twenty times Yes. I do the same except that I am too "anal" to not weigh every charge. I hope I did not come off as being "sloppy" in my loading. The techniques I may use on my own ammo is far removed from those I use in the loading of many thousands of rounds annually for others. I would assume your Lazzeroni death rays are already operating at the upper realms so there's little to be gained in pushing things. On the other hand, you have an ideal situation to evaluate the system that Ken Waters and Bob Hagel offered their readers. You use the same brand of cases and have been for quite some time. You "know" these cases. You also, likely have your favorite powders and primers too. Humor me and take readings for a period of time and see if the predictability is not as I have said. Then "play" with a new powder and work up a new load as we have discussed. I'll bet you you enjoy every minute! This is how the old farts at the gunshop got me hooked. Does it compare with sophisticated new equipment? No, but then it was never intended to.

Slamfire,
That sounds good to me. It is solid comparative data. Redundancy of technique and the repeated use of components tell much.
One point about the "softer" cases ... your system still works so long as you record repeated results that indicate, for example, your Remington brass expands + this over another brass with factory loads you know you can adjust the figures for your top handloads using the softer brass. I have a number of "best loads" for the same rifle that demand different brands or lots of brass.

Slamfire,
I missed something in your post. In this system we are not taking readings on case heads, only @ the expansion ring, as it sets up just outside the chamber.

OK Shooter......very, very nice!

Nickudu....I've been there and done that and worn out a barrel or two so now I find a good solid load that gives me the accuracy I want with sufficient velocity. In the case of my Lazzeroni Hellcat it's enough to take money from the boys at the range with their "tuned" factory .223s. I am working up a new custom barrel on my Patriot that is showing some amazing potential for velocity combined with scary accuracy using Nosler Partitions. BUT my new pride and joy is on the way .... a switch-barrel varmint rifle with a slow-twist .22BR barrel and a fast-twist 6BR barrel...watch out as my 'smith tells me he was shooting in the low 0.2s when he fire formed some loads for testing. Oh me oh my the little p'dogs better watch out.

Good thread I feel, but I get the impression that people are loooking for a fool proof way of determining pressure. If you are you will be looking forever. Even the factories make mistakes. I think the last time I looked at Winchesters Web Site they were recalling ammo because of pressure problems and I am sure we have all seen recalls in magazines over the years. So here goes. DB said one must have a standard to go by and that is good. Set a standard by using factory loads for you firearm if available to you. As an example I wanted to work up some loads for the 458 Win Mag. I bought a box of Remington 500gr FMJ's [some of the last that Rem produced] and some Remington brass. I pulled some loads from the factory loads including the primer and loaded these into my brass and fired and measured the expansion on the belt and compared it to the Remington factory loads as the standard. Then I worked my loads up within 3 or 4 tenths under the expansion the factory load gave and called that my max. I also loaded that load into the factory load brass to double check expansion. Scientific no, but even labs in controlled situations make mistakes that is why we work with a cushion of safety either in our measurements or our switching components such as dropping back and working up again. Tight chambers should be safe with factory loads because in talking with ballistic techs pressure barrels are made to minimum saami specs or suppose to be. If your chamber is tighter than that I would have it changed. So use the factory load method I describe in developing a standard and test away. Now I am not going to argue with anyone on this thread because this subject can be RUN INTO THE GROUND because there is no foolproof way of determining pressure outside a ballistic lab and even then that is not foolproof because it depend on the fool using the equipment. I know what; we could always load 5 percent below starting load and then we would be safe until someone gets scared of going slightly under starting load. Oh well.

Metplat,
Nothing is foolproof. The system I try to convey is designed to provide a methodolody with which to identify thresholds of pressure in their particular rifle prior to the arrival of coincidental pressure signs. In my view, such is mostcertainly preferable to having to incrementally stoke each new loading until a "wipe" is evident on the case head and then backing off a grain or two, as so many have done for so long. It has worked well for me and I feel I am as careful as the next guy when it comes to reloading.

While aware of the various limitations of both, I use both PRE and chrono data.

I feel no need to get the absolute maximum velocity -- for hunting loads I am looking for the most accurate load that's in the right velocity "ballpark" -- e.g., for the .30-30 or .30 Remington I'm starting to play with, I will use whatever powder & 170-gr. bullet is most accurate at around 2200 fps. For the 7mm-08 I'm picking up, the general purpose load will be whatever gives good accuracy with a 139-140 gr. bullet at 2800 fps, etc., etc.

PRE does depend on brass hardness, etc. but I get maximum PRE numbers before you get sticky bolts, etc., so PRE measurement does beat waiting for those!

Besides, I figure Ken Waters has been using PRE measurements to work up all his loads for 40 or 50 years now, and he's still around to tell the tale in each month's Handloader. (Actually, if you compare his loads to "book" loads using the same bullet and powder, his maximum charges are usually the same or a grain or so lower, which tells me his method is soundly conservative.)

John

John Frazer,
Good post, as usual. I neglected to mention that the chronograph has always played a major role in my loading proceses also. Gunwriter, Bob Hagel takes the system a good bit further than Mr. Waters, as Bob leaned towards the use of hot magnums for his hunting, as did my "mentors".

Happy New Year ... Nick

DB Bill: In the 'it don't make a dam bit of difference dept'-- that test of Mcpherson's running at 95000 psi sorta begs an explanation as to why. What is learned or gained, factored against the risk?

Is that testing published anywhere on the web or review?

aladin...it wasn't a test that McPherson ran, one he observed at a lab..check out the latest issue of Varmint Hunter magazine. Nothing comprehensive just mentioned in passing while talking about the problems of trying to use brass expansion to estimate pressure.