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 Post subject: Re: Burn rates
PostPosted: Tue Jan 12, 2021 10:19 am 
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Joined: Tue Jun 15, 2004 11:55 am
Posts: 5513
Location: Hemingway, S.C. 29554
So there!! If burn rate was the only thing involved, we wouldn't need to do load testing but it is much more complicated than that. I find burn rates interesting but I pick my loads from published, tested data except as proven safe by testing & established ballistic principles. Trying to understand what makes things tick is never a bad thing but ignoring safety standards is never intelligent! Put a different way, the intelligent use of knowledge is rarely counterproductive.




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 Post subject: Re: Burn rates
PostPosted: Tue Jan 12, 2021 10:41 am 
Crown Grade

Joined: Sun Mar 03, 2013 11:01 am
Posts: 6315
Location: Newton Kansas
B.L.E. wrote:
OldStufferA5#1911 wrote:
if you double the size of that fixed volume, the pressure will drop by 1/2.
Thus, every time that a bullet base (straight-wall cartridge) or wad gas seal doubles the distance from it to the inside base of a cartridge, pressure drops by half.


That relationship between volume and pressure only holds true if the gas is maintained at the same temperature during the expansion. The rapid expansion of the red-hot gasses behind the bullet essentially undergo adiabatic expansion and the pressure not only drops due to the increase in volume, but also due to the decrease in temperature so the pressure will be significantly lower than 1/2 when the volume doubles. Your gun is a heat engine and it converts heat into energy via gas expansion.

Yes, it does, BUT, I was deliberately ignoring Thermal Change (Heat Loss) for the sake of K.I.S.S.
Keeping It Simple.

BTW, gasses are very poor conductors of heat (solids and liquids work far better) AND, the conduction of heat requires time.

Care to quantify the amount of heat lost to that gun barrel in 0.008 seconds, AND, while at it, care to quantify the Thermal Change (cooling) simply caused by the expansion of the gas?
I'm not going to.

_________________
I don't always venture out into the sub-freezing darkness, but when I do, it is hunting season, and I carry a Browning. Stay hungry my friends.


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 Post subject: Re: Burn rates
PostPosted: Tue Jan 12, 2021 10:58 am 
Crown Grade

Joined: Sun Mar 03, 2013 11:01 am
Posts: 6315
Location: Newton Kansas
geometric wrote:
So there!! If burn rate was the only thing involved, we wouldn't need to do load testing but it is much more complicated than that. I find burn rates interesting but I pick my loads from published, tested data except as proven safe by testing & established ballistic principles. Trying to understand what makes things tick is never a bad thing but ignoring safety standards is never intelligent! Put a different way, the intelligent use of knowledge is rarely counterproductive.


When did anyone proclaim that Burn Rate "was the ONLY thing involved"?

And, while I'm asking, When did ANYONE, including moi, advise NOT using "published tested data"?
If I did, please be so kind as so show me where I did?


"Burn Rate" does a great deal at explaining TWO things.

WHY that "published tested data" exists.

And

WHY a lot of data people seem to foolishly look for, DOESN'T EXIST.

"Can I use CFE223 in my .300 Blackout? I can't find any data for that?"
Answer: No, you can't, which is WHY you don't find it, and WHY is it is vastly wrong Powder Burn Rate.

"Can I use H110 in my .45 Auto" I can't find any data for it?"
Same answer.

"Can I use 700X in my 7.62 Soviet? I can't find any data for it?"
Same answer.

On and On and On and On, how many more do you want? I can just hit Sage's Reloading Supplies on Facebook for dozens......... without even hitting The Net At Large.


"Can I use IMR4350 in my .308W?"
THIS one actually has SOME data, but it's a lousy fit, like trying to make 1000fps traploads out of Longshot.
You can, literally (seriously), FILL the .308W case brim full, tamp it down, THEN cram a bullet in there, packing it further (they are called Compressed Loads), and the TESTED LOAD, won't even get within 10,000psi of the cartridge MAP.
50,000psi in a 62,000psi cartridge, and velocity is marginal.
Why?
Because the BURN RATE is just too slow for the use.
Choke the bore diameter back to .243" instead of .308", and that powder now makes sense, because the pressure drop from the bullet expanding the burn chamber, is slower, because the bore is smaller in relation to the case volume.



Since you don't think I can claim Boyles Law, go ahead and do me the educational favor of explaining which ACTUAL branch of physics gas law explains the pressure trace behavior we see correctly, since Boyles "doesn't apply".

I'll check back tonight.
Thanks.

_________________
I don't always venture out into the sub-freezing darkness, but when I do, it is hunting season, and I carry a Browning. Stay hungry my friends.


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 Post subject: Re: Burn rates
PostPosted: Tue Jan 12, 2021 11:18 am 
Crown Grade

Joined: Sun Mar 03, 2013 11:01 am
Posts: 6315
Location: Newton Kansas
geometric wrote:
we wouldn't need to do load testing

YOU, don't "need to do load testing".

Someone else did it for you.

You don't "need" to test anything, you WANT to, don't misdirect it to some universal "need" requirement.

YOU, to put a fine point on it, "feel" the "need" to go do your own load testing, because you won't take someone else's word for what THEY got, on their day, in their gun.

And the funny thing is, the Load Testing YOU have done, STILL isn't done in your gun anyhow, so you still, at the end of the day, are STILL taking someone else's word for it.


There is 10,000 times more "secondary load testing" on this site, by people here, than I have seen anywhere else, by anyone, anyplace, across the entire internet, across the entire hobby of Home Ammunition Manufacturing.
In 2 decades across the internet, in 4 decades of making ammo, the number of people I have seen ELSEWHERE to have handload ammo tested, by a commercial entity, wouldn't occupy both hands (and I do have all 10 fingers).
Here, it's a constant.

Yep, people loading Metallic blow guns up.
Know why?
99% of them double-charge a low-volume, FAST BURN RATE, gunpowder, 2x as much inside a case as they should have, against a mere 30% Proof Load safety factor.
THEY screw up, by all the numbers.
They don't blow guns up because the load data was "wrong" until they mail 10 or 20 off to a lab to have them tested, and THEN, it STILL wouldn't apply, to THEIR gun.......... :mrgreen:


I think maybe I'll go shoot some "untested" ammo today, nice, calm day, and warming up.
I need to see if a scope is failing (I believe so) on 1 rifle.
I need to test a couple other loads in a different rifle than original to.
Want to see how the Blackhawk likes those 170's atop the casefull of 300MP. BOOM!!!! :mrgreen:

_________________
I don't always venture out into the sub-freezing darkness, but when I do, it is hunting season, and I carry a Browning. Stay hungry my friends.


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 Post subject: Re: Burn rates
PostPosted: Wed Jan 13, 2021 10:32 am 
Crown Grade

Joined: Tue Jun 15, 2004 11:55 am
Posts: 5513
Location: Hemingway, S.C. 29554
I think you missed the point. No, of course you don't have to do testing if you use reliable published data. It is very desirable to have good data, ie: test data, if you change things. You can roll the dice if you like & I wish you luck but personally, I don't depend on luck! Also, all published data is not reliable. I don't know if it is true or not & I'm not calling any names but it has been alleged that certain sources have been pumping out volumes of data that has been computer generated.


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 Post subject: Re: Burn rates
PostPosted: Wed Jan 13, 2021 12:28 pm 
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Joined: Thu Mar 05, 2009 10:56 pm
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Location: Central ND
The companies that produce tested data following SAAMI guidelines, to the best of my knowledge are:

Hodgdon, Alliant, Lyman, Precision Reloading LLC, Downrange Wads, and Reloading Specialties. Claybuster, I believe has someone else test their data as well as Hodgdon, Alliant & Lyman include data for Claybuster wads. Tom Roster has(had) his data tested by a lab, the last I knew it was H.P. White, but that could have changed. (H.P. White Laboratories closed down in March 2020)

I may have missed a smaller outfit or two.

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Mark

aka Mr. Tactful. Common sense no longer appears to be common.
NSCA#544066


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 Post subject: Re: Burn rates
PostPosted: Wed Jan 13, 2021 1:23 pm 
Crown Grade

Joined: Tue Jun 15, 2004 11:55 am
Posts: 5513
Location: Hemingway, S.C. 29554
"The companies that produce tested data following SAAMI guidelines ----"
I agree, at least I have no reason doubt what you say! I am sorry to hear H.P. White is closed. They were testing loads for about $1 a pop back in the late 50's & early 60's. I talked to one of their people sometime near the year 2000. That was when I was told their motto was, "One good test is worth a thousand expert opinions."


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 Post subject: Re: Burn rates
PostPosted: Wed Jan 13, 2021 1:48 pm 
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Location: Central ND
Yup way back around 1987 or so I had a conversation with H.P. White.....it wasn't $1.00 a shot any longer. If I remember correctly, they wouldn't check less than a 10 shot string and it was pricey. The fellow there suggested that I just use published data, which I did.

Tom Armbrust and Precision Reloading testing for $5.00 a shot is a BARGAIN.

_________________
Mark

aka Mr. Tactful. Common sense no longer appears to be common.
NSCA#544066


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 Post subject: Re: Burn rates
PostPosted: Wed Jan 13, 2021 4:31 pm 
Crown Grade

Joined: Sun Mar 03, 2013 11:01 am
Posts: 6315
Location: Newton Kansas
geometric wrote:
I think you missed the point. No, of course you don't have to do testing if you use reliable published data. It is very desirable to have good data, ie: test data, if you change things. You can roll the dice if you like & I wish you luck but personally, I don't depend on luck! Also, all published data is not reliable. I don't know if it is true or not & I'm not calling any names but it has been alleged that certain sources have been pumping out volumes of data that has been computer generated.

Allegations are not "evidence", are they.

I could "allege" a great many things, were I to do you,,, you would THEN immediately demand "evidence" (unless you were a complete idiot).


That noted, there is A LOT of "computer generated" data out there in the handloading world.

A very popular, and apparently successful, piece of software out there is called Quickload.

https://www.neconos.com/quickload-balli ... -software/

$160 and a copy of it could be yours.

I don't use it, but, from decades of discussions on various other werbsites, I could whip up hundreds of users, just within the tiny, microscopic, portion of The Internet that I frequent.

Quote:
New CD-ROM version 3.9 requires Windows XP, Vista, W-7, W-8 or W-10. You can import information from the QuickDESIGN program into for QuickLOAD for ballistic analysis-exterior and interior! NEW FEATURE!! Schematic and/or photos of most cartridges in library are available at the click of a button. Scaled photos of the selected propellants.

More than 1200 cartridges
More than 250 powders
More than 2500 bullets
Abundance of Useful Outputs
Customize cartridge selection for your firearms
Dimensioned drawings and photos of many cartridges at the click of a button
Interfaces with the PVM-21 and PVM-08 Chronograph
QuickLOAD/QuickTARGET $152.95
Fast, accurate and easy!


However, we handloaders all know, WE are the "last line developer" of that ammo in our guns. All QL does, like any book, is give us parameters to work within, to find out what our rifle or handgun shoots best with.

Those users, don't blow up guns from Quickload data.

They blow up guns when they misread gunpowder canister labels (wanting RL17 and getting RL7, 4198 instead of 4350), or they screw up by double-charging (10gr of Bullseye in a .45 Auto, 46gr of 4227 in a .308W). They don't blow up because QL said the "maximum" was 1-grain too high.


This isn't just "library database" that is full of other sources tested loads, it is a calculation program, that calculates internal ballistics behaviors using a myriad of variables, case volume, bullet weight and bore size, gunpowder Burn Rate, and on and on.

Quote:
Q: I have .223 necked down to a .0076 wildcat need boomer – is that in there?

A: If there is a round that you have that is NOT in the database – YOU CAN ADD IT IN. As long as you read the manual and have good measurements, play around with cartridge dimensions all you like. The program is completely user-editable.


That is, I believe (I could be wrong, again, I don't use it, never have, never read the manual) only a program for metallic cartridges, a bit more "straight-forward" loading, AND YET, a loading task with far less "fudge", far less "flexibility", and far easier to "blow up" in your face, that shotshells have ever been.

_________________
I don't always venture out into the sub-freezing darkness, but when I do, it is hunting season, and I carry a Browning. Stay hungry my friends.


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 Post subject: Re: Burn rates
PostPosted: Thu Jan 14, 2021 11:52 am 
Crown Grade

Joined: Tue Jun 15, 2004 11:55 am
Posts: 5513
Location: Hemingway, S.C. 29554
"The fellow there suggested that I use published data, which I did."

Me too! That's definitely the path of least resistance. However, that sometimes leaves a few cracks unfilled, particularly with some non toxic shot types that don't have much published data & vintage guns that nobody loads ammo for or publishes a lot of data for any longer.


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 Post subject: Re: Burn rates
PostPosted: Thu Jan 14, 2021 4:12 pm 
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Joined: Sun Mar 03, 2013 11:01 am
Posts: 6315
Location: Newton Kansas
Yep, at times, in some corners, whether it is for OLD powders or Brand New, or some old, or new, projectile, SOME oddball combination that has either been long forgotten, or has not yet been tried (literally, hundreds of millions of possible combinations, only 24 hours in a day and 365.25 days in a year, with new things being created regularly), there's just no way to expect with any reasonableness that everything possible will ever get tested before it gets displaced by The Next Great Thing.

And when you find yourself in that corner,,,, what does one do?

Just forget it and walk away, or try to figure out, with whatever information IS available, how to make safe and effective use of something.......



_________________
I don't always venture out into the sub-freezing darkness, but when I do, it is hunting season, and I carry a Browning. Stay hungry my friends.


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