quote:

Originally posted by WAH:
That manual was from 1990 and I had it, did not copy it and it sank. I am absolutely certain it was there, but not sure which year it was. Why should liability become an issue if a hand loader has a better idea what he is doing?

Regards

WAH

I have Hodgdon #25 (1986) and #26 (1992). Not in either.

Because this is information that no powder company is going to release to the public.

Sounds like he is looking for "Bomb Calirimeter (sp)" data.

I would not doubt that powder/testing labs have their version of this.

It's a foregone conclusion that no two rifles will give the exact same pressures or velocities using the exact same load. Any handloader with any amount of experience and chronograph will confirm that. Even the books are just guidelines and often even starting loads will give excessive pressures in some rifles. That's why the people who distribute these books put these exact warnings on the first page. So calculating velocities over the length of a barrel can only realistically be done with the barrel in question and with proper pressure testing equipment. Anyone who thinks otherwise is dreaming.

I've actually seen this hundreds of times over the years. Some one does something silly and rather than admit to it they try to find some way to prove that they are not to blame. They call the manufacturers with their woes and they get the old: "listen buddy, you screwed up." Then they try other venues in hope that by some magic they can undo the error they made, or at least shift the blame. If the manufacturers thought these people had a leg to stand on they would be paying them out as fast as they could to put out the fires. Obviously in this case, they aren't.

It is very simple, I do it when I need it, but I need the powder specs of all powders so that any shooter can do it for his load and his powder. Dont you understand that?

WAH

Werner von Braun supplied the basics of your space program. And who says I am trying to design a super duper silencer? No, pressure calculations are most important for a gunsmith, so I am in the right forum.Mechanical engineers are seldom ex[posed to deal with extreme pressures as we are.
The point is, I have been ridiculed that it is not necessary and it can not be done to calculate pressure in a weapon.

WAH

See my post with winchester powder specs?
WAH

Thank you, I am sure it was on a left page, on the bottom half of the page.

Regards

WAH

Hi Louis, we are coming closer,but I did not know this name, I am learning. I know it is simple referred to it as 'bomb', but some people might suspect I am trying to blow up something. Oh, but I did deliberately blow up 5 AK/AKM. It was quite an effort to get that right. Louis if you know the name of this 'bomb', do you have a few more morsels if information please?

Regards

WAH

Oh no, you are twisting my words. I never said that pressure calculations are to b e done in my head, but referred to recoil velocity of a slide.

To do 9 calculations if you like or obtain 9 results in one go we need to measure the velocity, have the distance the bullet base travels under pressure (different to barrel length)and of course bullet weight etc and powder specs.
You will get: WCC pressure assuming all powder is burned but bullet has not moved (only of interest when developing low vel ammo and other experimental loads)
Max pressure
location of max pressure
From (land diam + groove diam)/2 you get the true barrel internal diam. Tha is (7.82+7.62)/2 you get about 7.72 assuming equal with of land and grooves.
This you need to calculate the cross section to calculate from the pressure the force applied to the bullet.
from distance of bullet travel and force (not the same as pressure)you get acceleration
From acceleration over barrel length you get barrel time or velocity.
You get muzzle pressure from gas generated into the volume of shell plus barrel.
Supplemental info you can obtain about barrel strength of the barrel profile, gas exit velocity
and gas energy of the muzzle blast.Forgot kinetic energy and the recoil impulse in g/sec.
One shot you get a complete profile of a cartridge rifle combination. That not all barrels are the same is a fact, but that reflects in the difference of velocity measured. But the core of this is, the velocity is the result of the acceleration. Losses of friction and heat do not come into it, but they do exist. Whatever they, is the result of the force. are net acceleration (might be a better term)
From velocity and twist you get revs/min or revs/s if you like (but I am sure you know that)
You also get IBE in g/mkg, efficiency (how much of the powder energy is converted to kinetic energy), kinetic energy, recoil velocity if you enter weight of weapon and recoil energy.
You can extend this to obtain penetration of mild steel and add on or predict velocity changes of a hypothetical barrel,but the latter part is not 100% accurate, but good enough for a forensic investigation and used by criminologists or arms designer. I did not look it up, but if I have not forgotten anything, there must be 9 important and accurate results.
Many years ago I wrote a basic program, I think it was 60 modules, I have transferred some of it to 25 spread sheets which I can make available to anybody, but these spreadsheets are of no use if you do not have the powder specs. Also included is a conversion table relevant for a shooter/hand-loader. Nothing special, just for convenience. HANDY TO HAVE. For a scientific explanation you can read one day one of 17 booklets, that is if I live long enough to finish them. Right now, it does not look good with my health, but I would like to pass on my knowledge before I kick the bucket.

Maybe you guys going to get it now.

Somewhere somebody said: At first there is violent resistance, then comes ridicule and then it is accepted as universal truth. No problem, we are nearly in stage three.

Regards

WAH

WAH, I can't help you because I do not have the pressure/temperature/energy data, nor have I ever seen it. I am not a chemist or ballistician, I am an engineer, and do not do this for a living.

I think we have somewhat of a cultural/language barrier getting in the way here. The simple answer is that nobody here so far that has replied has the pressure/temperature/energy data.

Regardless of units and calculations, the reality is that most pressure/velocity work done in the USA is done empirically with actual test barrels and cartridges. Manufacturers MIGHT do some calculations based on test lots, but I think most simply do a ballistic test and compare to the results of previous tests using that barrel and cartridge. I don't know if European manufacturers do the same, or have different methods.

I for one am not ridiculing what you're trying to do, I'm trying to point out what I think is a fallacy to it. That fallacy is that the burning of powder in a cartridge in a rifle barrel is not a simple calorimetric chemical reaction. The amount of energy and the temperature is dependent on the conditions under which the reaction takes place, and as I understand the reaction, the results are non-linear when graphed against the reaction conditions variables. That is the primary reason USA cartridge pressure data is obtained with actual test firing of the powder under controlled conditions. As I understand it, manufacturers test each lot individually, as well as random testing ammunition pulled from the assembly line at periodic intervals.

The other fallacy is that the characteristics of each powder vary lot to lot. So, there is a range of pressure/temperature/energy for each lot, even when evaluated under the same conditions.

Again, good luck in your endeavors, I indeed hope that you really do have a new and better way to do things and can develop it, articulate it in an understandable way, and pass it on to the world knowledge base.

dave

Hi Dave, yes you are reasonable. But I do not believe that in the USA powder with the same name has vastly different characteristics. If that were so, you need not even give the powders a name. I think you will agree to that.
Further, imagine you are a European gunsmith and have to build a drilling (you know these contraptions with three barrels), say in 7x57R, a .22 Hornet and a cal 16 Shot-barrel.that would cost about US$ 20 000.- or more and take two years or so to build.
The problem is that you can not make the chambers and barrels as fleshy as o a bolt action rifle, the drilling would be far too heavy. So you have to calculate the pressure and forces for the material you use to go for minimum safe dimensions in relation to the material strength you are going to use. The only way to do this is to calculate pressure in the weapon. You have to agree to that as well. And for that you need to do the pressure calculations. No powder manufacturer can help you with the loading data only.
Liability has been mentioned here as well. In fact, if a rifle blows because the manufacturer failed or refused to provide information, the manufacturer could be sued.
Dave I am not trying to do something new at all. I have consolidated ballistic formulae that needed many steps with a calculator, into a spread sheet.
I have posted some data on Winchester powders, have a look on an earlier post.
At a stage (before I retired) I had a good wire to SOMCHEM (South African Powder manufacturer, part of the ArmsKor group) and got free samples of newly developed powder types for evaluation. And I know as a fact the Somchem tested and recorded the requested powder specs to ensure uniformity. I do not believe that Somchem was more advanced the other powder manufacturers.
If you are an engineer, which I believe you are, I am prepared to send you some spread sheets and you can play with it. In the meantime, check the Winchester powders I listed whether or not they are not out dated. If they are not outdated, select one of your own loads if you have used such powder, or any one from the loading table and you can run some tests.
The material is copy right and it will not be available by itself because people would not understand what they do. It will only available as integrated part of a booklet of about 80 or so pages on internal ballistics.
After using it, you can report back here. What would be more reasonable? Just check the availability of listed win powders.
Then we correspond directly via email. I am not on social media, no spam from me and hopefully no virus either. So what can you lose? Be a man and go for it.

Regards

WAH

Hi Dave one more. Irrespective of friction (a negative), additional heat of the primer (a positive), chamber and barrel sizes (pos or neg)and ambient temperature, the velocity is the result of an acceleration which is an exact value and can be expressed exactly and internal chemistry does not even come in to the equation, but is only a process that reflects in the acceleration, but we need not be concerned about that at all. Think of this very carefully, that is most important.
I have spent enough time to unsuccessfully try to obtain the powder specs. But it has confirmed to me, that due to the imperial system, there is much understanding lacking indication to me on some points I have to emphasize. I have asked for a definition of slug-foot. What an awful thing it is.
So I am waiting for a pm from you, but notify me here, I only reply, I do not creep aroudn the forum.

Regards

WAH

This is the data QuickLoad uses to calculate internal ballistics:

Hi Thank you. I believed so, but a gunsmith and friend of mie assured me that only the chemical energy of the powder is given in quickload and that alone did not make sense to me. So I shall go into it. Because if a powder manufacturer gives the one value, he has to have the other two as well.
He is a German engineer and I shall get onto him.

Thank you so much.

WAH

Hi Dane, I did not have much time earlier on. There is no way I can ever get quickload at my location.
Question, can one actually see these values or are the hidden? I have only heard good about quickload and that German engineer surely knows what he is doing if he is using this data.

But I believe my spreadsheets allow for unknown factors, such as developing a load for a hypothetical .17 BMG and get velocity and anything you like.
Your co-operation would be most appreciated.

Regards

WAH

"But I do not for one second believe that powder manufacturer first make a ton of powder, then load some cartridges and compare it to the last batch and see what is happening?"

That is exactly how it is done.

They make the powder based on their best guess, try it, blend it, ajust the load, then when happy they then load it. They do not have the ability to make powders that are exact in burn rate. Burn rate is mostly controlled by grain size and shape. Canister powders for re-loaders are blended to a spec. Bulk powder used for factory loading are loaded to a achieve a result. They are not the same as what you can buy.

Calculating pressures is not possible. You need a strain gauge to measure what is actually happening.

Calculating pressure has been done for the last 100 years but if you can not do it, it does not mean somebody else can not do it. Qickload calculates presser successfully., but that is not done by guesswork engineering, but in the metric system.
Here nobody seems to be able to any of the simplest calculations such a slide velocity. So forget it, you have no clue what you are talking about. One day you can buy one of my 17 books (if I live long enough) and learn about Ballistics. Unless some information I asked for is forthcoming, I shall no longer argue with people who deny that 2x2=4 (in the decimal system that is)

WAH

You have mentioned your books several times. Could you provide a title or two?

And I get 23.26 ft/s. I presume you used 400 grams for the slide, 350 m/s for the bullet velocity and 8 grams for the bullet. With round numbers it's easy to do the calculation in your head and come up with 7 m/s.

Sorry, no use, I am far behind, but if you are very interested, you can help proofreading.
WAH

JohnD, you are 100% correct, but I doubt that you could have done that in your head in grains, ounces and ft/s. It needs a wunderkind to do that. And that is the argument against the imperial system, But in metric as you figured it our correctly it is:

slide weight/bullet weight = 400/8= 50 ratio

Then 350m/s / 50 ratio = 7m/s . Although you are right I could prove you wrong if the Vo of 350m/s was obtained from a (stationary) test barrel, then relatively to the ground the Vo of the bullet would be only 343m/s from a pistol with a moving slide going to the rear with 7m/s slide Vel. But that was not asked for.
I appreciate that you are the only one to make an effort.
I have written to Ferlach, but no reply yet. I have also to Germany BUNDESVERSUCHSANSTALT in Ulm who does the proofing of Firearms. They replied positively. but wanted my CV so to speak which is reasonable considering the topic.
I have a suspicion, that given all world small arms powder specs, I find some with identical burning rate which they will not include (because from a scientific point are of no interest) but with vast differences of flame temp / gas gen and chem energy.

It seems to me you would like some spread sheets (in metric of course :-))
Keep it up