Conservative Data in Load Manuals

[LongRange]

gotcha...i had pretty much the same thing happen once or twice...but mine were not accidents...it was done to see how far things could be pushed before things started to fail...probable lucky im still around after some of the things ive done but ive always been one to push things right to the ragged edge...and past.

that said i had and played with quick load for a few months and stopped using it because i had to tweak the numbers to get it to match actual field velocities which i didnt care for...im old school when it comes to all of this...i load,shoot and watch for OBVIOUS/VISUAL pressure signs...and yes like darkker says all the time...when you see pressure your most likely over pressure...and i agree with that but for me personally and after pushing as far as i have im comfortable running over book max charges and velocities...but thats ME and MY equipment...for anyone else do your own testing and work up slowly...and when switching ANY OF YOUR COMPONENTS drop your charge weight and work up again...i learned the hard way about case capacity about 8yrs ago when i switched to a different brand of brass with a real hot load.

[barrel-nut]

Maybe try a different bullet/powder combination. I get a pretty consistent 2715 fps with 43.5 grs of Reloder 15 and a 168 gr. Hornady A-Max from a 24 in Savage barrel. This is also an accurate load in all of my rifles. I've gone up to 44 grs with it, but in our hot summer heat down here I start to get pressure signs.


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[bigedp51]

Case capacity with .223/5.56 cases can vary from 28.0 to 30.6 grains of H2O case capacity. This means the chamber pressure can vary 6,000 psi between these two case capacities. So your components used and your rifle can vary the pressure generated.

In the Lyman manuals they use universal receivers and pressure test barrels with chambers and bores cut to minimum SAAMI dimensions and this would generate the highest pressures. They also use data using strain gauges glued to the barrel when a specific firearm is listed in testing.

Quickload requires a chronograph to get semi-accurate guesstimates, and you adjust the burn rate in Quickload until the two velocities match.

Even reading primers or measuring the case above the extractor groove below is a guesstimate because of brass hardness.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads

Bottom line your manuals also tell you to start low and make workup loads checking for signs of excess pressure. Meaning all loading data is a guesstimate for "YOUR" firearm and components being used. And measuring expansion just above the extractor groove is the best method for the brass you are loading.

Now ask yourself why the table below was created, and why you can't load a 30-06 to the same pressure as the .270 Win in a modern rifle like a Remington 700?
Answer, there are too many older 30-06 rifles still being used today, and published load data is for the weakest link in the chain.

http://i.imgur.com/EPcuYSG.jpg

When measuring just above the extractor groove you are measuring the unsupported base of the case. And when the diameter of the base increases by the limits above you have exceeded the elastic limits of the brass.

http://i.imgur.com/IBJQA9p.gif

The same applies when brass flows into the ejector, meaning exceeding the strength and elastic limits of the brass.


http://i122.photobucket.com/albums/o254/bigedp51/index_zpsaiocbozg.jpeg

[ttexastom]

the method that is explained by bigedp51 is the .one that I have been using for years. ken waters explained this method many years ago. funny to me that with (waters) method on the 263 express back in early 60's that his load data matches up with nosler today with imr 4064. this is data that did not have a computer to tell you that. when my chronograph starts to match book velocities for a cartridge. time to stop! adjust seating depth and tune for best accuracy.

[MZ5]

This article:
https://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf
shows, with solid data, why measuring case head expansion, pressure ring expansion, whatever you want to call it, is very very nearly useless. Yes, if you get that expansion, you should back off a fair amount. However, brass variation is such that it _may_ tell you something completely different, or next to nothing at all.

[toddcdozer]

My 7 SAUM shoots H-1000 with a 175 ELD-X at 3043 FPS at .5 gr under max. At 5 gr under max it matched book max velocity. Chrono ran my other guns where they usually run so I am assuming it's good. My barrel is 27" vs 24" in book so maybe 50 FPS there. Still it's very surprising to run that fast. Scale weighed charges on my other rigs that ran as expected. So right now I'm 200 FPS over book with 3" extra barrel length and no pressure signs (I have seen pressure and this one aint in it).

Same scale and chrono ran 7828 close to book.

My gun is built on a LA and COAL is 3.1 so I have some extra room but is it that much? This thing is beating RUM book speed with almost 30gr less powder.

What now lol? I am tempted to call it good and stay .5 under but I am also thinking its kinda scary to be pushing a SAUM to RUM speed, long COAL or not.

My experience says I'm OK but I have never had this problem, I usually struggle to get to book without issues.

[bigedp51]

This article:
https://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf
shows, with solid data, why measuring case head expansion, pressure ring expansion, whatever you want to call it, is very very nearly useless. Yes, if you get that expansion, you should back off a fair amount. However, brass variation is such that it _may_ tell you something completely different, or next to nothing at all.

Actually its more accurate than reading primers and tells you you have reached the elastic limits of the brass. Meaning its strength and if you get the expansion listed at the Hodgdon's site its time to back off the load. If you don't back off the next thing that happens is you have over sized primer pockets. It doesn't tell you pressure in psi but it does tell you you have reached the elastic limits or strength of the brass.


The photo below came from a long range competitive shooter at AccurateShooter.com and the poster stated he increased the load until he got brass flow into the ejector. He then stated he backed off 1 or 2 grains and called this his maximum load, and proceeded to look for a accuracy node for his rifle.

http://i122.photobucket.com/albums/o254/bigedp51/index_zpsaiocbozg.jpeg

Measuring above the extractor groove isn't perfect, the Federal case on the left will expand sooner than the Lake City case on the right. This is due to the strength added by the thicker flash hole web "BUT" if the case starts to expand in the base it means the primer pocket will soon be over sized. Meaning this expansion does tell you a good deal about the case and how much it can take before going in the scrap brass bucket.

http://i.imgur.com/cYeTsDp.jpg

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests
http://bulletin.accurateshooter.com/2014/05/how-hard-is-your-brass-5-56-and-223-rem-base-hardness-tests/

Did I tell you this cheap bastard buys bulk once fired 5.56 Lake City brass because its built Ford Truck Tough, and a fraction of the cost of Lapua brass.

.223/5.56 - Cleaned, Deprimed & Swaged - LC Only - 500 Pieces $59.00 free shipping
http://brassbombers.com/223-556-Cleaned-Deprimed-Swaged-LC-Only-500-Pieces-2LC-S0050.htm

[MZ5]

You're probably right that it's more accurate (precise) than reading primers, since primers are roughly as precise as throwing darts at a board with a tarp over your head. :-)

Have a look at the paper. It was written by a person who has spent their career/life in statistical analysis, and in particular in the measurement business. The instrumented testing shows how significantly imprecise PRE/CHE is. A chronograph is a better choice with which to keep oneself out of trouble.

[hardnosestreetcop]

Randy85 even if you used the same components as the Sierra Techs used your results will still be different. One thing that will effect your results is did you crimp the Winchester brass ? Seating depth they used 2.750 and you used 2.800 the 0.05 difference could be a factor in the burning of the powder. My recommendation is that you start 10% down from the max load, that would be 39.2 grains, lower the OAL to 2.750. Load 5 rounds at 39.2 check the ACCURACY going up from there in .5 grains increments towards the max charge watching for signs of high pressure. Keep in mind your velocity will be 40 FPS slower than the manual as you go up, because Sierra used a 26 inch and your using a 24 inch barrel (20 FPS lost per inch 20x2=40). Good Luck

[bearcatrp]

Thanks for all this great info. Looks like I need to back off my loads that are above max listings in the book. Never really understood measuring volume with water but time to look into this. Dam, I have some sweet loads made up that are accurate as hell but almost 2.0 grains above max published data. I look at multiple listings in reload manuals and hodgdons web site to see how far I can push it. Hornady dropped max load for the 178 grain in there new book. Guess I should heed that.

[bigedp51]

This article:
https://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf
shows, with solid data, why measuring case head expansion, pressure ring expansion, whatever you want to call it, is very very nearly useless. Yes, if you get that expansion, you should back off a fair amount. However, brass variation is such that it _may_ tell you something completely different, or next to nothing at all.


You're probably right that it's more accurate (precise) than reading primers, since primers are roughly as precise as throwing darts at a board with a tarp over your head. :-)

Have a look at the paper. It was written by a person who has spent their career/life in statistical analysis, and in particular in the measurement business. The instrumented testing shows how significantly imprecise PRE/CHE is. A chronograph is a better choice with which to keep oneself out of trouble.

MZ5

I collected milsurp rifles and had a few Mosin Nagant rifles (Noisy Maggots) and the last thing I would do is test Russian made brass in a surplus rifle with a long fat chamber.

I would never trust anyone "who has spent their career/life in statistical analysis" let alone even recommend reading the testing of a surplus rimmed case made in the communist block countries.

And a milsurp rifle like a .303 British Enfield will have cordite throat erosion and a worn oversize bore which "lowers" chamber pressure. The loading data for the Enfield rifle is a safe load for all the older rifles being used today. And yet newer No.4 Enfield rifles were chambered in higher pressure .308/7.62 without any problems.

Now just look at the throat variations below for the .223/5.56 below and ask yourself if a max load in one rifle will be a max load with a rifle with a longer throat.

HOLLIGER ON .223/5.56 CHAMBERS
http://www.radomski.us/njhp/cart_tech.htm

http://i55.tinypic.com/211wdbb.jpg

In another forum a "engineer" was telling the forum to lube their cases to fire form them and double their bolt thrust because the case would not grip the chamber walls. When I told him this was very bad advice he told me I didn't understand and that he was a engineer. This so called expert was doing the math using the inside diameter of the case to give the theoretical figure the bolt thrust and thought it was always the same. I then asked him why the primers on my 30-30 loaded to 43,000 psi by the manual were backed out of the primer pocket and the rear of the case never touched the bolt face what would the bolt thrust be then. We have too many "experts" giving out bad advice and the reloader just needs to use common sense and read his brass.

We have too many midgets sitting at their computers pretending to be giants. Meaning over half the crap you read on the Internet is just garbage.

Bottom line all loading data is ball park information and you will not know what your case will withstand until you make up work up loads.

Example, a load in my AR15 rifle using harder Lake City brass shows no signs of excess pressure. "BUT" the same load using softer Federal brass will have case head swipes and this load is below maximum.

Even the pressure readings using the pressure trace system are ball park, because a cartridge of a known chamber pressure should be used to calibrate the unit. And this is stated in the reloading manuals about the strain gauge method of measuring chamber pressure.

There is a very good chapter in the Speer #9 manual called "Why Ballisticians Get Gray" and it shows all the velocity variations in .357 revolvers and rifles.

Bottom line, with all the variations in firearms and reloading components all loading data is ball park and why the manuals tell you to start low and work up your loads.

[Robinhood]

Nice Write-up Ed

[ttexastom]

very usless, strong language from a person that almost blew up a gun. there is lots of data out there but it must be used with common sense. maybe you can call all the loading companies and tell them what you know, am sure they will appreciate it. practical experience goes a long way! computers seem to be a way of life today, just learn the basics thru experience, and not trust some gadget or gismo. do you believe in global warming?

[bigedp51]

very usless, strong language from a person that almost blew up a gun. there is lots of data out there but it must be used with common sense. maybe you can call all the loading companies and tell them what you know, am sure they will appreciate it. practical experience goes a long way! computers seem to be a way of life today, just learn the basics thru experience, and not trust some gadget or gismo. do you believe in global warming?

The throat in my Savage .223 bolt action with a 1 in 9 twist is longer than my AR15 rifles. So please tell me what loading data should I use? The short throated .223 (.0250 freebore) data or the .0500 freebore data in the AR15 loading section.

99.9999999999999% of reloaders do not have "ANY" type pressure measuring equipment and all we can do is measure base expansion for a ball park idea of what the brass can take. And how many times in forums have you seen people talking about oversized primer pockets. (this is a big clue)

The British NRA banned tight bore rifles and oversized bullets from competition because the chamber pressure were going through the roof. And my worn .303 British Enfields like flat base bullets that when kicked in the seat of the pants fills the bore, and boat tail bullets in the same rifle will hit the target sidways.

In forums you have people telling you to lube your ammo the fire form the cases and this doubles your bolt thrust. So there is a lot of bad information on the Internet.

So tell me what rifle I almost blew up with your BS posting?

I take care of my brass and load conservatively and in over 46 years of reloading I have never even had a case head separation, let alone blow up a rifle.

I have manuals I bought in the 1960s up until today and people are still asking why the data varies.

The topic of the posting is "Conservative data in loading manuals" and the answer is simple.........

There has to be enough room in the rifles chamber to fit the cartridge and the company lawyer in also.

So make up workup loads starting low and working up and you will not have any problems when reading your brass for signs of excess pressure.

[bigedp51]

Nice Write-up Ed

Thank you, I will mark you down as being almost as smart, good looking and modest as I am.

For those that do do not understand dry humor.

"Deadpan or dry humor/wit describes the act of deliberately displaying a lack of or no emotion, commonly as a form of comedic delivery to contrast with the ridiculousness of the subject matter. The delivery is meant to be blunt, sarcastic, laconic, or apparently unintentional."

Or just plain "Bazinga" for you younger guys who wonder why load data varies.

[Robinhood]

I spoke too soon! LOl

[ttexastom]

very well done ed

[LongRange]

Does this look like to much powder to you guys?

http://uploads.tapatalk-cdn.com/20161217/ce7e70e2efb417f5e1fa5d6a31aa8eca.jpg


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[bigedp51]

Does this look like to much powder to you guys?


No, but it does looks like your too cheap to buy a drop tube.

P.S. Why is your case mouth all dinged up, did you wet tumble the cases or sprinkle glitter on the case mouth.

[earl39]

not according to how scope eye loads it ain't