quote:

"Why do you continue this blatant lie? You have been called on this lie by more members than just me. You varied the weight and the speed to artificially prove what you set out to prove". ..... Gerard

Here is your own post showing the table below:
Weight .... S365 Load .... AOL ...... Velocity ........ SD .... Penetration
175 gr ....... 38.0 gr ........ 77 mm ... 2,390 fps ... .310 ... 63.0 cm
142 gr ....... 40.5 gr ........ 75 mm ... 2,490 fps ... .252 ... 53.0 cm
108 gr ....... 43.0 gr ........ 73 mm ... 2,610 fps ... .191 ... 42.5 cm

Glenn,

Yes, do go over the figures and form an opinion. The crackpot I am refering to is to deny SD a role in terminal performance.

There is little point in keeping the lighter bullets at the same low velocity of the 175 grainer.

If we were to do that the penetration of the 2 lighter bullets would have been even worse.

The lighter bullets were loaded in a practical way, and so it is only natural that they would be propelled faster.

And since the case could house a few extra grains of powder, it also assits the velocity a bit.

Keeping the velocity the same actually requires down-loading - how dumb.

So there is no lie that is being perpetuated, it shows the value of SD - the correlation cannot be denied.

SD cannot be wished away - it works in a dynamic way whether a bullet shed petals, stay intact or tumble.

My test results correlate very well, and that's the way it is.

Let me repeat ..... HOW SILLY TO KEEP THE VELOCITY THE SAME !!!

How pathetic to say ... I artficially proved the outcome - it is all about correlation.

Warrior

quote:

by only varing the SD of a Barnes-X bullet (108 grains, 142 grains & 175 grains) and that proved to me the value of SD in a particular caliber with the same bullet, same construction and material and the same nose profile.

quote:

There is liitle point in keeping the lighter bullets at the same low velocity of the 175 grainer. If we were to do that the penetration of the 2 lighter bullets would have been even worse. The lighter bullets were loaded in a practical way, and so it is only natural that they would be propelled faster.

So, by your own admission, you lied. Now the spin to try and save the lost cause:

quote:

Keeping the velocity the same actally requires down-loading - how dumb. Let me repeat ..... HOW SILLY TO KEEP THE VELOCITY THE SAME !!!

Speaking about how dumb it is to down load, I recall you saying that down loading improves performance:

quote:

Down load and you will see a huge difference in bullet performance.

quote:

Just by dropping down to 2,500 fps, we can reduce the energy level by 1,060 Ft-lbs and so ease the stress on the bullet.

quote:

Loading your 450 Dakota down to 2,250 fps has more benefits than wanting to run it to 2,550 fps imho.

quote:

However with a down load to to 9,3x62 velocities it is not necessary.

Stupid is as stupid does, or is it Warrior speak with forked tongue.

Using a larger caliber,lower SD, heavier bullet with the same final expanded diameter as the TSX's in the test, at the same velocities, would "prove" that high SD reduce penetration.

At least as well as the cutting TSX test.

Yes Gerard, you are being profoundly stupid with your crackpot reasoning and your skew interpretation. What a farce and a pathetic reply - actually above expectation, but still way below average. You wanted the last say, but it is not helping your argument one bit - it is all there to see.

And get it into your thick skull ... THERE IS NO LIE - the results were posted in all its detail for all to see and it speaks for itself.

Just in case you are still not getting it, and I repeat myself ... SD is only indicative in a particular caliber with the very same bullet and loaded according to the bullet weight. THAT IS BEING PRACTICAL.

Over and out.
Warrior

quote:

THERE IS NO LIE - the results were posted in all its detail for all to see and it speaks for itself.

Right there is the lie. You do one thing and say another. Did you think that no one would notice? As for the smokescreen that all the bullets be loaded to the same speed; that makes you look doubly stupid.

quote:

Just in case you are still not getting it, and I repeat myself ...

You do, don't you?

quote:

SD is only indicative in a particular caliber with the very same bullet and loaded according to the bullet weight. THAT IS BEING PRACTICAL.

So you have said, also repeatedly, and therein is another lie. Why do you then make bullet/sd/penetration depth comparisons across manufacturing types? What allows you the right and no one else?

you two are going to bed with no supper.

Now play nice







SSR

quote:

Originally posted by Cross L:
you two are going to bed with no supper.

Now play nice







SSR

That's the first sensible thing said in eight pages.

Hi Gerard,

About ten threads below this one is a discussion of expected bullet performance of a GSC HV 130 grain bullet for a 7 x57.

What is the recommended velocity for the 140 grain GSC HV in a 7x 57 with the recommended 1 turn in 8" twist?

quote:

Just in case you are still not getting it, and I repeat myself ... SD is only indicative in a particular caliber with the very same bullet and loaded according to the bullet weight. THAT IS BEING PRACTICAL.

I agree to that, but I dont find it very useful. Explaining this to someone less anal than us would be easier by just saying that the heavier one will have a less violent expansion and penetrate more.

quote:

SD cannot be wished away - it works in a dynamic way whether a bullet shed petals, stay intact or tumble.

My test results correlate very well, and that's the way it is.

Let me repeat ..... HOW SILLY TO KEEP THE VELOCITY THE SAME !!!

Hi, Warrior.
I honestly wish you had tried to keep the velocity within the same range in all three cases to show once and for all whether SD is relevant to penetration or not.* But it's your time and your dime, so to speak, and I did like your tests just as they are.
(*Actually, you did this pretty well.)

I used the simple version of the momentum density (sectional density times velocity) to see how well it lines up with your tests. It turns out that all you have to do is to divide by the constant 11.75 and you'll get a really good approximation of your results.


Weight....Velocity.......MD.......Penetration
-------------------------------------(actual/predicted)
175 gr-- 2,390 fps -- 740.8 -- 63.0 cm/63.0
142 gr-- 2,490 fps -- 626.3 -- 53.0 cm/53.3
108 gr-- 2,610 fps -- 499.3 -- 42.5 cm/42.5

So the momentum density works pretty well as a predictor in this case!

Glenn,
One could also vary the speed to prove that SD has no bearing in this example:

175 gr-- 2,100 fps -- 651.0 -- 55.4
142 gr-- 2,600 fps -- 655.2 -- 55.8
108 gr-- 3,500 fps -- 668.5 -- 56.9

Where Warrior purposely used an artificially low speed for the light bullet, one could use an artificially low speed for the heavy bullet and "prove" the opposite. It all depends on what one sets out to prove. Warrior devised a test to prove that SD is the driving factor and massaged the numbers to get the effect he wanted.

Cross L,

quote:

Now play nice

Oh come on! this is Warrior we are dealing with. He does not know how.

quote:

One could also vary the speed to prove that SD has no bearing in this example:

175 gr-- 2,100 fps -- 651.0 -- 55.4
142 gr-- 2,600 fps -- 655.2 -- 55.8
108 gr-- 3,500 fps -- 668.5 -- 56.9

Gerard, are those results from actual penetration tests or are they from the formula I used? As I understand it, there's a point where increased velocity has a negative effect on penetration, and I would have thought that the lightest bullet at 3500 fps would have penetrated less and that you would have needed to tweak the constant.

Glenn,

When I set out to do the test, I had no idea how it would come out, so it was impossible to purposely get a manipulated result. I followed Somchem's guideline for the heaviest bullet available for the caliber, namely the 175 gr bullet, that is a rather longish bullet for the 7x57 mm case. I still wanted to achieve a near top velocity without experiencing a bolt that would not open from too high a pressure. I did not know what velocity my rifle would yield at this point in time, as it was a new load being shot for the very first time. So this was a stab - I am sure I could have loaded the 175 gr even higher, as I did not experience pressure problems.

I then cut 6 mm off the bullet's base each time, so I could end up with a lot of 175 grainers, 142 grainers and 108 grainers. Again it worked out this way that the lightest 108 grainer was now 12 mm's shorter, so it could still be loaded and have enough purchase in the case mouth. I could have done the shortening with 3 mm's or 4 mm's if I wished, but I wanted to get slightly bigger jumps in lowering the SD to be more indicative. The weights that I obtained was incidental, as I did not know ahead of time by how much they would drop.

Somchem's advice was to load the 175-gr bullet with 38 grains of S365 and for each lower weight I increased the charge with 2.5 grains to fill the vacant space in the cartridge case. Naturally a higher charge would drive the lighter bullets faster, and so getting its momentum values up again, and the results popped as follows, having no idea what the penetration differentials would be:

Weight .... S365 Load .... AOL ...... Velocity ........ SD .... Penetration
175 gr ....... 38.0 gr ........ 77 mm ... 2,390 fps ... .310 ... 63.0 cm
142 gr ....... 40.5 gr ........ 75 mm ... 2,490 fps ... .252 ... 53.0 cm
108 gr ....... 43.0 gr ........ 73 mm ... 2,610 fps ... .191 ... 42.5 cm

All the above loads could be maxed-out with no more than 2 grains of powder, but I did not explore that, as the penny had fallen - the results correlated quite well with Mo/Xsa, and the value of SD had been demonstrated.

All bullets retained 100% of their weight and expanded to 2x diameter, not bringing other variables into the equation, so as to rip the petals off and thereby changing the cross sectional area (Xsa). That is why I chose the Barnes-X bullet in the first place, and not an unbonded thin-jacketed frangible soft bullet.

Our ballistic system favours weight over velocity, and the momentum value of the 175 grainer (high SD-bullet) cannot be made up by lighter and faster bullets in the 7x57 mm cartridge, but should it be possible somehow to do anyway, then the petals would be ripped of in short order, and so the bullet would go through the heart of the animal as a solid with a tiny hole and the value of a double expansion is lost.

The Barnes-Bullet loses its petals around 2,700 fps impact velocity, and I drove the 108 grainer to 2,610 fps still being within the threshold strength of the bullet. So picking a velocity of 3,500 fps for a 108 grainer is a not practical at all and simply a non-event in a 7x57.

And that is the way it is.

Warrior

Glenn,
I used your formula.
-------------------

Warrior,

quote:

the petals would be ripped of in short order, and so the bullet would go through the heart of the animal as a solid with a tiny hole and the value of a double expansion is lost.

Evaporating petals again. Goodness, your experience is limited.

quote:

So picking a velocity of 3,500 fps for a 108 grainer is a not practical at all and simply a non-event in a 7x57.

How would you get a 110gr bullet up to 3500fps in a 7x57? You would need about 40" of barrel. Best to use a 7mm RM for that.

As a matter of interest, a 116gr HV, from a 7.21 Lazzeroni, shoots clear through an eland broadside. It left a permanent wound channel you could get three fingers into and an exit hole the same size. The damage in the chest cavity was a sight to behold. Of course you won't know about the kind of performance one can gain from high speed monos, because you have never done it or seen it. Just like you cannot tell people about a place you have traveled to unless you have been there. Hole through the heart..... you are funny at times.

quote:

How would you get a 110gr bullet up to 3500fps in a 7x57? You would need about 40" of barrel.

40 inches of barrel is the figment of your imagination.
At some point the velocity would drop off long before it reaches the 40" mark and so deteriorate.
By this very logic one could argue that 60" would be better, hey?
It just shows your lack of understanding of internal ballistics.

The subject of discussion here is a 7x57, and not any faster 7 mm magnums for that matter.
Why mention a 7 mm Rem Mag ... you are totally off the wall.
Your arguments are getting weaker and weaker and more irrelevant.

You are so practical.
Going to the bush with a 40" barrel ???
Your pearls of wisdom is quite something.

Warrior

You miss the point so well, one would think they give rewards for point missing.

And you miss the point of SD completely, and so be it.
Read again what Norbert Hansen had to say about SD.
Read again what Karl Sellier had to say about SD.
Your rejection of the value of SD will not make it go away, nor deminish it.



Warrior

Gerard and Warrior,

Were you two seperated at birth or what. Either of you would crawl a hundred miles just to piss in the others soup.
Agree to disagree and get over it.

Gerard,

quote:

quote: 465H&H
I am always interested in the results that other hunters find in the use of bullets in elephants. Please give us the following info on these to reports. When, where, what species sex, age, bullet make, weight and caliber, velocity, entry point and where the bullet was found.

Gerard Quote:
This is the tactic I follow when sidestepping speed fines. I ask the issuer for all the relevant paperwork and keep them tied up with correspondence until they decide that the bit of money is not worth all that trouble. So, to you I say: Continue to believe that RN lead core solids are better than FN monos. Continue to "test" and "prove" your opinion using antiquated and incorrect methodology. Continue to use bullets contrary to recommendation, after all, what do the manufacturers know? They have no clue what an ele looks like and thumbsuck their bullet designs and just hope they work. You are not worth the trouble of continuing the discussion because you do not pay attention.

465H&H,

I asked this question in an effort to learn just as I posted. You made the statement on what three PHs told you and I have every right to ask for details. Do you even have them or are these PH statements simply a figment of your imagination? It would take you only a medium sized paragraph to give us the details which is much shorter than your usual posts. Quit putting up a smoke screen by accusing me of sidestepping the issue. It is you that sidestepped the question. Your veracity and honesty are on the line here.

quote:465H&H
I can recommend any or all three of these bullets for elephant with the caveat that the next elephant taken may change my opinion.


There we go. Confirmation that you have not explored all the variables and you know it.

465H&H: That is an absolutely true statement, but unlike you with your closed mind, I keep an open mind. I know I don't have all of the answers as no two bullets encounter the same amount of bone or tissue on their passage through an elephant. Once you close your mind you lose the capacity to learn.

Explain to me why the 550 grain .458 Woodleigh RN bullet at 2,150 fps will exit on quartering from top of head down cow and bull heads while the NFFN 480 grain .465, 500 grain .475,500 grain .475 FN CEB#13 or 500 grain .458 Hornady DGS all at 2,150 fps will not exit on similar shot placement? In this case a RN solid out penetrated several FN solids. Maybe it has to do with the extra 50 to 70 grains of bullet weight.

465H&H

Cross L,

Welcome to the discussion bud. I am sure you found Gerard's latest comment hilarious and must admit that you had some fun reading the various posts - it's all for entertainment.

Just to enjoy it once more, this is the kind of logic and reasoning pattern ... Gerard is honestly and seriously suggesting that 3500 fps can be obtained with a 40" barrel in a 7x57. This must be an all time classic to make lost momentum up with velocity. Hell, this is original.

And on this high note, we are set to start the day with a smile, if not with hysterical laughter.

Warrior

I posted:

quote:

How would you get a 110gr bullet up to 3500fps in a 7x57? You would need about 40" of barrel. Best to use a 7mm RM for that.

Warrior reads this into it:

quote:

40 inches of barrel is the figment of your imagination. By this very logic one could argue that 60" would be better, hey? It just shows your lack of understanding of internal ballistics.

As I said, you miss the point so well. But your rabid lack of comprehension does not stop there, you continue with:

quote:

Just to enjoy it once more, this is the kind of logic and reasoning pattern ... Gerard is honestly and seriously suggesting that 3500 fps can be obtained with a 40" barrel in a 7x57. This must be an all time classic to make lost momentum up with velocity. Hell, this is original.

You should have attended a school where reading and comprehension was on the curriculum.

quote:

quote:
How would you get a 110gr bullet up to 3500fps in a 7x57? You would need about 40" of barrel
Best to use a 7mm RM for that.

You offered the above as a solution to get the momentum value up - how idiotic !!!
Totally removed from reality.
And then you throw in a 7 mm Rem Mag in that is not even the point of discussion.
Another irrelevant red herring.
Situation hopeless.

Warrior

In summary then, an increase in SD leads to less energy transfer to the target per unit distance penetrated, and thus deeper penetration. The lower the SD the shallower the penetration, but the bigger the energy dump cause a bigger temporary cavity.

In our current ballistic system, a higher SD value comes with more MOMENTUM and less ENERGY, and this is the point that Karl Sellier makes, and the important point being that we cannot make up lost momentum with more velocity and achieve the same terminal result.

Could it be that Karl Sellier has lost all his marbles?
Professor Karl Sellier, University of Bonn.

Warrior

PS: One of his publications:
Wound ballistics and the scientific background
Karl G. Sellier and Beat P. Kneubuehl.
Published 1994
A reference work used by forensic scientists.

quote:

Originally posted by Warrior:
In summary then, ...

quote:

Originally posted by Hot Core:

quote:

Originally posted by Warrior:
In summary then, ...

what's this?....sixteen pages of summary?

Just for the general hell of it, I tossed through some of my old "academic" physics books and a few others that have been collecting dust since my days in college. I even stumbled upon one I've been meaning to read but lost it. A great read if anyone is interested in quantum theories it's called Quantum Enigma by Bruce Rosenblum (08). In any event, I was trying to show earlier in this thread that SD in no way plays any significant role in "penetration". And some-where along my posts I took the long way around the barn explaining why and when all things are equal than perhaps it may apply. But the chances of all things being the same is as remote as "impossible". So here is a direct quote of the "base law" defining what I suggested earlier. Sr:;New England Journal of Physical Principles. MW 1989

"A study commissioned by the United States Army regarding anti-personnel bullets shows that besides sectional density several other parameters determine bullet penetration. However, and only if all other factors are equal, the projectile with the greatest amount of sectional density will penetrate the deepest."

So I hope one will regard cross section, and non-directional density (in whole or part) along with "retained energy" to provide more detailed penetration of any given mass.

For those who continue to believe, think or otherwise insist that SD plays a significant role in substratum/mass penetration, needs to stop spewing bull-snot all over these boards and shimmy down Yuma way for a spell and tell the worlds finest munitions engineers they are all full of B.S., then explain to them as you have on these boards how they are wrong!

Put a damn fork in this thing. SD is beyond the understanding of most and it doesn't help to quote others, pretend you know what you're talking about and drag solutions in from off the street and other boards. It simply doesn't work, it never has, probably never will. Talk about something you know about, something interesting and something you can teach others.

quote:

So I hope one will regard cross section, and non-directional density (in whole or part) along with "retained energy" to provide more detailed penetration of any given mass.

For those who continue to believe, think or otherwise insist that SD plays a significant role in substratum/mass penetration, needs to stop spewing bull-snot all over these boards and shimmy down Yuma way for a spell and tell the worlds finest munitions engineers they are all full of B.S., then explain to them as you have on these boards how they are wrong!

Put a damn fork in this thing. SD is beyond the understanding of most and it doesn't help to quote others, pretend you know what you're talking about and drag solutions in from off the street and other boards. It simply doesn't work, it never has, probably never will. Talk about something you know about, something interesting and something you can teach others.

Point taken.

Strange that we get the following from another physicist:-

"Sectional density has to do a lot with penetration. Multiplying with velocity it gives a figure of momentum density, the basic number for all penetration research. To overcome the drawback of the greater length of pure copper bullets, manufacturers recommend the use of lighter bullets, the greater muzzle velocity would compensate for the lower mass. This can accepted for normal hunting conditions, but applied to non-deforming bullets (solids) for dangerous game hunting it can become a disaster. The lower sectional density results in less penetration (see Penetration Index), because less weight normally can not compensated by more muzzle velocity in safe pressure limits.

There is another, very important reason to use bullets with a SD greater than 0.3: We don´t know exactly the drag function in animals and it must be very complicated. But one fact is for sure: The heavier bullets are less decelerated than the lighter ones. Heavier bullets loose less velocity during their travel through the target. That means: heavier bullets keep their momentum, lighter bullets loose more momentum on their travel through the body. And keeping momentum results in deeper penetration." ..... Norbert Hansen.

Also very strange what my own tests revealed.

Warrior

Here we have a concise and logical summary of SD in the "internal ballistics" realm:-

"Do not be confused as to my point of view or my position on Sectional density, I simply stand on the science of ballistics.

Our ballistics system in terms of shoulder fired small arms has limits as imposed by mainly the pressure cieling of the cartridge case.

This limitation has far reaching consequences for the inernal ballistics event.

The first and most obvious is a limitation on the maximum possible velocity attainable in any cartridge as determined by Sectional density.

As you make the bullet mass smaller and smaller for a given caliber and a given combustion volume, ie reduce the SD you reach a point where velocity increase actually reaches a maximum and then starts going down.

If you increase the SD for a given caliber and combustion volume you find that velocity drops off untill the maximum pressure limit is reached.

It is fact that of all the factors that determine maximum velocity of a bullet in the bore, or pressure for that matter SD is the largest contributer or determinant.

It forms the basis to which we choose loads for all the catridges we shoot. Any load recipe ever devised hinges on this principle.

In oposition to this we have the external ballistics problem. Here we find that for a given caliber bullet, shape and construction the higher the SD the greater the efficiency of the bullet in terms of it's ability to retain velocity over distance and to overcome attempts at change in direction of motion.

But here to we have a limit in maximum allowable SD as determined by the stability theorem.

For a given caliber bullet, shape and contruction increasing SD means the bullet has to be longer, the stability theorem limits the maximum length of the bullet thus ultimately the maximum SD possible for a bullet." ..... Alf

Warrior

Penetration in flesh (terminal ballistic realm):-

Penetration is dependent on drag in flesh.

So why would a heavier bullet be better off than a lighter one?

Because in penetration of visco-elastic soft solids the resistance to penetration is related to the square of the velocity, and dependent of representative area (Xsa), and so bullet weight makes a bigger contribution to penetration than velocity. Less drag on the bullet makes for better penetration.

Furthermore, the high-SD bullet invariably hits the target with more terminal momentum, as our current ballistic system favours weight over velocity by virtue of the pressure ceiling in internal ballistics.

The heavier bullet translates to the principle that you want more weight behind the frontal area (Xsa).

SD is one of the fundamental and integral building blocks.

Warrior

"I just need to clarify something for the speed over mass freaks:

In 1982 Karl Sellier published in his book Shusswaffen und Shusswerkungen, Second edition: his tests on the effect of increasing velocity in lieu of mass in non deforming stable projectiles specifically with regards to the issue of SD and penetration. (updated edition published in 1994)

They also validated this by means of experimentation and a valid mathematical derivation that would explain at the hand of energy transfer to target what happens when you speed the projectile up by trimming weight as Gerard suggests with his FN bullets.

The results of the tests show the following:

1. An increase in SD leads to less energy transfer to target per unit distance penetrated and thus deeper penetration. The lower the SD the shallower the penetration, the bigger the energy dump to target and the bigger the TC." ... Alf

Warrior

quote:

Originally posted by someoldguy:

quote:

So I hope one will regard cross section, and non-directional density (in whole or part) along with "retained energy" to provide more detailed penetration of any given mass.

For those who continue to believe, think or otherwise insist that SD plays a significant role in substratum/mass penetration, needs to stop spewing bull-snot all over these boards and shimmy down Yuma way for a spell and tell the worlds finest munitions engineers they are all full of B.S., then explain to them as you have on these boards how they are wrong!

Put a damn fork in this thing. SD is beyond the understanding of most and it doesn't help to quote others, pretend you know what you're talking about and drag solutions in from off the street and other boards. It simply doesn't work, it never has, probably never will. Talk about something you know about, something interesting and something you can teach others.

Point taken.

I've been on a slow burn ever since I made this post. No, "point" isn't exactly "taken" at all. I have a right to my opinions, and my observations, and by God I'm going to express them within the confines of decency. I was just sick of the arguing and having to defend my position against those who seem to just half-ass read what I wrote. Or didn't understand it to begin with, I don't know. And against those who think I just don't know what I'm talking about. But if you don't read what I wrote, I'm under no obligation to read what YOU wrote, regardless of how many animal carcasses you show or what counterpoints you make. If I've made any errors in my own observations, then I'm sure I'll have the intelligence to see them and correct them in my own time.

I don't need for you to worry that I'm making mistakes or misleading anyone. I never said that I was here to educate anyone or teach anything. I'm pretty sure that I've made the proper caveats whenever I post things. I've said "The way I see it is..." "From my understanding..." "I estimate..." You know, these aren't little buzzwords. They do have meaning. These indicate that I'm expressing my opinion, my position at the time. I'm not telling or asking anyone to accept.

Regarding the specific topic of sectional density. This isn't my creation. This has been used over the ages by such scientists as Poncelet and by the more contemporary Karl Sellier. These guys weren't idiots. They weren't advancing some flat-earth theory because Sellier, in particular, made a pretty extensive study. He likely knew what he was talking about. But the only reason I bring this topic up about sectional density is, not because Sellier or Poncelet said it, is because it makes sense to me. And I'm likely not the only one.

But really, this is about decency. I don't care if you disagree with what I say. That's not what bothers me. What bugs me is HOW you disagree with me. If you'd like to point out some errors in logic, math, physics or whatever, then I'll listen to you. But if I feel that you don't have anything to contribute other than arguing or telling me I'm wrong without showing why and how, or making snide little references, then I'll assume you really don't know. Gerard doesn't agree with sectional density, but he has class and is a gentleman (despite what the equally classy and gentlemanly Warrior might tell us) and I'll listen to what he has to say.

More about decency: what really bothers me about what one person did wasn't even a comment. I halfway ignored it at first, but it began to gnaw at me. (Again, the slow burn.) It was a photo of a young man obviously with Down's syndrome posing with some kind of superhero cape with something like "Sectional Duncity" on the front of it. For various reasons I won't get into, I found that extremely offensive and uncalled-for. Really downright indecent. (I didn't even have the stomach to go back and look at the photo to see what the caption was.) Immediately I put that member on ignore. But shortly afterwards I recanted briefly. Big mistake, I see. Whatever comments he makes from now on, just like those of another member, are of entirely no interest to me any longer.

But if I have an opinion or observation to share, you can damn well rest assured that I'm going to share it, regardless of whether anyone thinks that I "know what I'm talking about" or not. If I'm troubling you by my point of view or I'm getting out of your comfort zone for your own pet theories, then you probably need to put me on ignore too.

quote:

In 1982 Karl Sellier published in his book Shusswaffen und Shusswerkungen, Second edition: his tests on the effect of increasing velocity in lieu of mass in non deforming stable projectiles specifically with regards to the issue of SD and penetration. (updated edition published in 1994)

I'm familiar with Sellier's work and would sure like to get my hands on a copy of that book, but it's hard to find here in the US. I'd even be willing to get the German version. My German is pretty rusty because I haven't used it in a long time, but I suppose I can relearn.

"Ich lerne, du lernst, er lernt..."

Glenn,

I feel the same way as you about some of these pictures that were posted by the one 'gentleman' that kicked off a with a steaming hot turd picture, which is even more offensive than the retard picture. If we take the sum total of the time that this man spent here on this thread then I am sure he could have written and laid-out his knowledge pretty well ... but he opted not to do so ... his objective was to derail rather than to share ... to impress without giving clear guidlines and to be pompous from his elevated throne.

Then back to Prof Karl Sellier - interesting to know that Prof Bo Janzon studied under Prof Karl Sellier. The CV for Professor Bo Janzon can be seen at this link, and his educational background is as follows:

Master of Science, Engineering Physics, Royal Institute of Technology, Stockholm (1968)

Doctor of Medical Science (Ph.D.), Göteborg University (1983), at Dept. of Surgery, on a thesis on "High Energy Missile Trauma - A Study of the Mechanisms of Wounding of Muscle Tissue". Faculty Opponent was Professor Karl Sellier, University of Bonn.

National Defence College, Institute of Higher Total Defence Education. Basic and Extension courses (1999-2001)

His experience is even more impressive.

http://www.secrab.eu/CVBJz.htm

He was also a past chairman of the International Ballistics Society and Research Director, Scientist at FOI, Swedish Defence Research Agency.

http://www.ballistics.org/news_manager.php?page=6584

Retired in 2007 after distinguished and extensive experience within Security and Defence Science and Technology, with 39 years at FOI (Swedish Defence Research Agency) and its predecessor FOA, as a scientist, project manager, and as a Section Head and Division Director for 19 years.

This man is arguably the best arbitrator in this discussion and his published papers may well be worth a read, but we may have to go back to university for a 5 year course in mathematics.

Warrior

Dr. Janzon is the author of more than 100 unclassified scientific and user reports and articles, plus many classified reports not listed here. He has also made hundreds of presentations on widely varying topics.

http://www.secrab.eu/Publications.htm

Warrior

quote:

I feel the same way as you about some of these pictures that were posted by the one 'gentleman' that kicked off a with a steaming hot turd picture, which is even more offensive than the retard picture. If we take the sum total of the time that this man spent here on this thread then I am sure he could have written and laid-out his knowledge pretty well ... but he opted not to do so ... his objective was to derail rather than to share ... to impress without giving clear guidlines and to be pompous from his elevated throne.

Well, the only thing I'm sure of is that he did demonstrate a knowledge of using clip-art. But enough said about that.

I first heard about Sellier in Edoardo Mori's Italian-language ballistics website. He has a lot of information.

http://www.earmi.it/balistica/default.htm

You could probably translate it with Google, but sometimes Google's technical vocabulary is lacking.

quote:

Originally posted by vapodog:

quote:

Originally posted by Hot Core:

quote:

Originally posted by Warrior:
In summary then, ...

what's this?....sixteen pages of summary?

Looks like the "In Summary then" was just the warm-up on a few practice laps.

Hot Core,

If you cannot make a positive contribution here, there is no need for your snide remarks; just skip the thread instead, as it requires far less effort from you. However, if you can share some pertinent information with us on the subject at hand, it would be greatly appreciated, even if you do not agree with any poster here on this thread. That is life and so we learn.

By the way we are only at page number 8 now.
But as I say, your posting did not bring anything new to the table.
It was a just stifling comment with no value attached to it.
It is up to you how you want to play it.

Warrior

WhatThe,

Your following quote.

quote:

"A study commissioned by the United States Army regarding anti-personnel bullets shows that besides sectional density several other parameters determine bullet penetration. However, and only if all other factors are equal, the projectile with the greatest amount of sectional density will penetrate the deepest."

So I hope one will regard cross section, and non-directional density (in whole or part) along with "retained energy" to provide more detailed penetration of any given mass.

For those who continue to believe, think or otherwise insist that SD plays a significant role in substratum/mass penetration, needs to stop spewing bull-snot all over these boards and shimmy down Yuma way for a spell and tell the worlds finest munitions engineers they are all full of B.S., then explain to them as you have on these boards how they are wrong!

With all due respect it appears that you are carrying their results beyond what they said and making determinations that they never made.
The way I read their results, is that SD does play an important role in penetration but that there are several other factors that also determine penetration depth. A non-inclusive list would include velocity, bullet weight, bullet construction, nose shape and caliber. None of these act alone but work together to produce a result in penetration depth. Another factor that has not received adequate consideration here is the type of media that the bullet penetrates. Whether it is simulated media or live animal tissue and bones.

465H&H

Warrior's corrected post, from the Energy/Momentum thread, which proves that BC is determined by form factor not SD:
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Only two factors drive trajectory and wind deflection, and they are:

* the launch velocity, and
* the BC, which is derived from SD and the form factor of the bullet.

A higher SD in a given caliber can move the BC up or down. A higher form factor in a given caliber always increases BC.
Therefore, BC follows form factor and does not follow SD.

With sniping today in the 300 Win Mag, with a twist rate of 1-in-10", the longer bullet of 190 grains is preferred over shorter bullets (lower form factor) such as the 168 & 175 grain bullets.

The 190 gr Sierra Matchking bullet has a BC of .533

By comparison:
The 190gr Berger has a BC of .583 - SD is the same as the 190gr SMK but form factor is higher and BC is higher than the 190gr SMK.
The 175gr Berger has a BC of .537 - SD is lower than the 190gr SMK but form factor is higher and BC is higher than the 190gr SMK.
The 175 gr SMK has a BC of .505 - SD is lower than the 190gr SMK, the same as the 175gr Berger but form factor is lower than either and BC is lower than either.
The 210gr Berger has a BC of .631 - SD is higher, form factor is higher and BC is higher than the 190gr SMK.
The 210gr SMK has a BC of .645 - SD is the same as the 210gr Berger but form factor is higher and BC is higher than the 210gr Berger.
The 220gr Hornady has a BC of .271 - SD is highest of all these bullets but form factor is lowest and BC is lowest.

So, in the sniping world, with the 300 Win Mag, the bullet with the higher form factor is the preferred bullet.

I have not modeled the trajectory as yet nor the wind deflection, but the military has opted for the higher form factor bullet and I take it that it was for a good reason.
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