All this leaves us with one question that the Sd fans do not want to answer: Why do we get more penetration with the same bullet, as speed increases?

As a matter of interest, the above statement is only true up to a point. With every bullet a speed will be reached, beyond which penetration starts dropping off again.

Sd also has some value: It is a good indicator of how much a bullet will expand if two bullets of similar construction are compared at the same speed.

quote:

Originally posted by Gerard:
All this leaves us with one question that the Sd fans do not want to answer: Why do we get more penetration with the same bullet, as speed increases?

As a matter of interest, the above statement is only true up to a point. With every bullet a speed will be reached, beyond which penetration starts dropping off again.

What about the non deforming solid FN type bullet?

You are only saying that there will be diminishing returns in increasing penetration as velocity is increased for such a solid, right?

Of course some softs will blow up and hardly penetrate at all at some point in velocity increase.

quote:

Originally posted by Gerard:
All this leaves us with one question that the Sd fans do not want to answer: Why do we get more penetration with the same bullet, as speed increases?

As a matter of interest, the above statement is only true up to a point. With every bullet a speed will be reached, beyond which penetration starts dropping off again.

.

Gerard,

You are the only person with this question. If one has a bullet, it MUST have velocity to WORK... and there's an envelope that velocity is effective in doing that work... if one takes vel. and mass, you get momentum... and any IDIOT knows that zero vel = zero momentum...

but what a minute...

we've both agreed that velocity helps penetration to a MAXIMUM point.... and then velocity actualy DECREASES penetration...


and, for the ender of this entire thread

If HIGHER MOMENTUM values alwasy mean better penetration, how can one rationalize that when the vel is too high, the bullet wont penetrate as well as a lower vel?

Answer? Why, of course, it goes back to bullet construction and SD.... with velocity being a variable and Momentum being an ARTIFACT

jeffe

.

quote:

Originally posted by ALF:
There is a point in this specturm where velocity, mass and frontal area meet and give the best penetration and that lies somewhere in the 338 - 366 (8.5mm to 9.3mm) caliber range with a bullet mass of around 250 gr and fired at maximum velocity for the pressure cieling of that bore (true frontal area ).

This can by calculated by Poncelet's equation.

Except for this quote above which could be argued in the real world as something more like .366 to .416 (possibly to .458) with some more mass; ....these seven pages have really started to evolve! (At least in a very resistive target)

At last we start to talk about the fruit stand instead of our favorite piece of fruit!!!

Even Gerald's last post concedes to more than one fruit in our stand! Pages of comments about disintergrating softs and bronze cylinders can be compared to a nice ripe bing cherry if one has enough imagination..... Propelled with a tremendous momentum value the blood-red flesh will soon "blow" away leaving the hard pit! But alas, even our hard pit can be further excelerated until it to disintergrates at a much greater speed. The pit doesn't care too much about MO/XSA; its demise is more related to structual intergrity and target resistence that increases right along with the pit's ever increased speed!

Gerald even tells us that enough speed will eventually "bend" us back to losing penetration again, even with our hard pit (bronze cylinder) and he must be commended as it isn't a favorite fruit for him!

There is no telling what we may learn if we continue to talk about the fruit stand instead of our favorite piece of fruit! Already the "fruit" frontal area is talked of more and more!

If Alf and a few others in these seven pages can just keep us on track now; who knows, we may see the additional pages add up to the greatest penetration of all!

BigRx

I tire of this discussion.

For the real world big game hunter:

Use a simply dumb SD of 0.3 or as close as possible with available bullets. The SD's significantly higher than this are more than simply dumb, they are then stupid.

Make that bullet as big in caliber and as fast as you and the sporting arm are safe, comfortable, and proficient with. This allows a spread of high velocity smaller bores for long range and smaller game, as well as a range of larger bores at lower velocity for DG and bigger game up close.

Best velocities for up close will be 2100 to 2700 fps with the biggest bullets being best around 2400 fps, for practical purposes, and best penetration. Always use a good bullet for terminal pefrormance required. >/= .375 caliber may be the minimum size bullet allowed by African Law in some situations.

Best velocities will be 2700 fps and above for the smaller calibers to be used at long range. Always use a good bullet for terminal performance required.

It is that simple.

Now you can get complicated about good bullets for the terminal performance required.

One bullet to do it all is a 300 grain .375 at 2700 fps.

This is called the "Keep It Simple Stupid" principle.

RIP,
I think the statement holds water regardless of bullet shape or method of construction. Across the spectrum, from pure cast lead bullets to tungsten darts, a speed is reached where the opposing force on impact will cause the bullet material to yield. When that happens, the projectile Mo/XSA decreases and penetration reduces in relative terms to the absolutes applied. (Doubling the speed will not double the penetration and neither will doubling the weight.)

Jeffe,
Your post is interesting as it is sort of on the right track. You say:
"You are the only person with this question." And this is the question you cannot bring yourself to answer although you know what the answer is.
"If one has a bullet, it MUST have velocity to WORK... and there's an envelope that velocity is effective in doing that work... if one takes vel. and mass, you get momentum... and any IDIOT knows that zero vel = zero momentum... " This is part of the answer and you are getting there in a roundabout way, no speed = no momentum.

"but what a minute..." Ok. I am waiting.....

"we've both agreed that velocity helps penetration to a MAXIMUM point" There we go, I cannot find where we agreed but it is accepted. Now why was that so difficult?

".... and then velocity actualy DECREASES penetration..." There you go falling out of the bus again. Velocity seems to be the causative factor in decreasing penetration, but I actually gave you a clue above. It is really Mo/XSA (or Sd x V, loosly put), that is the cause of reduced penetration in a given combination of circumstances.

"and, for the ender of this entire thread

If HIGHER MOMENTUM values alwasy mean better penetration, how can one rationalize that when the vel is too high, the bullet wont penetrate as well as a lower vel?

Answer? Why, of course, it goes back to bullet construction and SD.... with velocity being a variable and Momentum being an ARTIFACT" And just when I thought you truly do not grasp the concept, you actually reason it out for yourself.

Alf,
"I fail to understand how Gerard can claim it does not exist as he did 7 pages ago but has just a few posts ago now conceded that there is such a thing as true SD ?" I have never claimed that Sd does not exist. I have said all along that it has little to do with penetration and I thought my post above mentioning Sd was quite clear. Comparing two bullets of similar construction and similar speed fired into a similar medium, the one with the higher Sd will deform more than the other. That is the only place where Sd can be applied as a rule.

BigRx and RIP,

Do not dispair. I think the vast amount of nitpicking over single issues has served a purpose in clarifying some issues, at least for some.

The reality of diminishing returns as speed increases, is something that is closely coupled to how a bullet behaves upon impact. Looking at a particular cartridge in isolation (any cartridge), no one can deny the advantages of more retained speed in the external ballistics phase, providing that terminal ballistics do not diminish.

Ultimately we turn to bullet construction and design to ensure that terminal ballistics are what we desire and again no one can deny that the designs and construction methods today are superior to those of the past. What we have today are bullets that will increase the versatility of most cartridges, allowing each to be applied over a wider spectrum of game (bigger and smaller) and distances (further and closer) than before.

The success of a hunt rests on two aspects: 1. The ability to hit the spot. 2. The bullet must not fail in the specific application.

quote:

Originally posted by Gerard:
This is part of the answer and you are getting there in a roundabout way, no speed = no momentum.

.

quote:

Originally posted by Gerard:
As a matter of interest, the above statement is only true up to a point. With every bullet a speed will be reached, beyond which penetration starts dropping off again.

quote:

Originally posted by Gerard:
Velocity seems to be the causative factor in decreasing penetration, but I actually gave you a clue above. It is really Mo/XSA (or Sd x V, loosly put that is the cause of reduced penetration in a given combination of circumstances.

any more questions? I give up agruing that SD changes things.. Gerard makes that point perfectly and clearly

jeffe

Gerard,
wow, i just had a DUH! moment...

and I now realize why you are so dead set against SD being the starting point for penetration.


Since you make monmetal bullets, with a specific gravity lower than conventional bullets and monometal bullets are longer for weight (too long for "high" sd) then it is incumbant upon you to support ANYTHING other than SD for that measurement.

To put it another way... a 500 gr .458 bullet is FAR longer than a 500gr conventional bullet, which either would lead to an unusual shape, a loaded round that it too long, or a reduced case capacity (compared to a conv. bullet at the same OAL), and in all events, changes what a reloader would have to do to get performance.

Of COURSE you would support momentum (it's easier to drive a shorter/ligher bullet faster) over SD, because of the construction of your product.


And I have to say, I can fully understand your marketing.

I also feel that adding a nominal .02 to SD for monometal bullets is probably warrented...

if someone would do a one to one test of the same bullet shape and length compared to penetration of monometals vs conventionals, we could back into that effective "addition" to SD.

and now, back to gerard's marketing compaign.

jeffe

Jeffe,
You are slow on the uptake. Chris tried this angle two years ago as well as Pieter earlier in this thread. It is a sad excuse when you are backed into a corner and have been proven wrong

If you had followed the thread from the top you would have seen on page four that I answered this silly argument with:
"We make high Sd bullets but our thinking and technology has advanced beyond the point where we worship at the altar of a false Sd. We actually make a number of bullets in excess of 0.3 and all the way up to 0.486 but we do not tout that as a feature, because we know it is not. We also have a bullet with a Sd of 0.069 and it is more fun than a bag of dried mopani worms in Port Elizabeth."

Try something else as a distraction this one is too transparent. Would you like me to explain again about Sd and reduced penetration in clearer terms?

quote:

Originally posted by Gerard:
Jeffe,
Chris tried this angle two years ago as well as Pieter earlier in this thread. ?

if the shoe fits..

i guess keeping it layed on, thicker and deeper was thought in your customer service classes

You are so predictable.

I geuss you never noticed our high Sd bullets, hence the embarrasment and effort at diverting from a technical discussion to name calling again. Talk about if the shoe fits.

.

quote:

Originally posted by Gerard:
You are so predictable.

I geuss you never noticed our high Sd bullets, hence the embarrasment and effort at diverting from a technical discussion to name calling again. Talk about if the shoe fits.

Gerard,
You don't have to get your back up.. we all understand that a man has to eat. In fact, G, i would say you've been taken to task and failed every techincal point brought up. Interesting that you would infer *I* was name calling, when you are AGAIN brought to task over a fact you can't explain away.

So, to phrase this correctly, the "joe schmoe" who thinks of bullets and performance thinks of three things (hint, it aint SD or Mo)..

1: caliber
2: Muzzle energy
3: velocity

he doesn't KNOW to care about bullet weight, as this guy will somehow tell you that a 444 marlin is "better" than a 338 winmag for huntin

So, just to let us all know where YOU are coming from, i have ONE question.

1;what's the LENGTH of you 500 gr 458 bullet?


Just answer this one little question..



jeffe

Which one?

BFaucett,
Have a heart. Look at Jeffe's post above. He strings together three unrelated and incomplete trains of thought preceded by an unfounded statement and then you hold me to ransom. You know I like dogs and I have not seen your face so I cannot ID you in a line up..... Can't we negotiate about this....please don't shoot the dog. Pretend you did not read the following.

Chris,
One thing has emerged from this thread and that is that Mo/XSA is only a comparative indicator of penetration if both bullets strike similar media and react to the retardation in similar manner. Mo/XSA cannot be used to indicate lethality. It cannot be used to determine what size animal could be taken successfully. In a moment of absurdity someone suggested that my 22 x 64 would not be much use on an elephant despite a quite respectable Mo/XSA number. Ultimately the size of the animal will dictate what level of force we apply and then, some tools with similar numbers will work better than others because they are more effective in delivering the force to the target.

Mo/XSA also does not = Momentum Density. Momentum density is is the amount of momentum per unit volume expressed as kilograms per second per meter^2.

Posting for Chris Bekker:

RIP's new system - simply dumb or stupid?

Rip,

"Use a simply dumb SD of 0.3 or as close as possible with available bullets. The SD's significantly higher than this are more than simply dumb, they are then stupid." ... Quote


I respectfully disagree with your new system, Sir. Let me explain why:

Example: Going to the 500 Jeffery we get an SD of only .294 for a 535 grainer (stubby bullet 29.5 mm), which is 'good' per your system and when we move the SD up to .313 for a 570 grainer (better proportioned bullet) your system classifies the result as just over the top, ie simply 'dumb'', but not quite stupid as yet. But when we go to 400 grain and 500 grain bullets in .416 and .458 caliber respectively, they are completely 'stupid' according to your system, as they feature high-SD's of .330 and .341. Stupidly too high? What am I trying to say -

a) Bullet length to diameter ratio's are not the same for all calibers for a specific SD (say .300). The common .308 180-gr Nosler Partition bullet (31.75 mm long) gives us a multiple of 4.06 times its diameter, the .423" 400 gr Woodleigh SN bullet ( 31.83 mm) gives us only a multiple of 2.96 times, whereas the .510 535-gr Woodleigh SN bullet (29.5 mm) gives us only a multiple of 2.27 times. Proportions are very different in deed! Rip, I am writing this to you just before you struck off most of the old Big Bores or at best make their owners feel stupid.

b) Some cartridges were designed with longer free-bores than others, allowing the use of longer bullets, such as the 7 mm Mauser (173 grainers) in contrast with short free-bores such as 7mm-08 (140 grainers).

c) Some cartridges have short case dimentions (case, shoulder & neck) pointing to the use of shorter bullets.

d) A long-cased cartridge like the 300 H&H can take longer bullets by comparison than a short-cased cartridge such as the 300 WSM.

e) Shooting a short and light bullet (350 grainer, SD = .279) in a 404 Jeffery is stupid - you still won't make it a long-range cartridge with the marginal velocity that is gained. The 400 grainer is much more sensible (SD = .319).

f) In some calibers though an SD of near .300 look just right on the eye - for example a 286 grainer in a 9.3 caliber for an Sd of .305 and the same could be said of the 375 H&H (300 gr, SD = .305). Even the fabulous 250 grainer (SD = .313) in .338 caliber looks perfect to me, but also falls pray to your new reference sytem, as it boders on stupidity. Is the 250 grainer in the 338 Lapua not your favourite? Does that also make you stupid or do you shoot lighter bullets to fall in the SANE category of below .300?

g) With your new system you won't be making new friends with the Swedes, who love their 6.5 x 55 mm's - still the most popular cartridge today in Scandinavia. They have a legal requirement to use 156 grainers on elk - these bullets feature an SD of .320. This puts all Swedish hunters in the STUPID category. Why do these high-SD bullets give such excellent performance with modest velocity? Their better weight retention conserves the momentum far better as opposed to lighter and faster bullets that shed more weight. Simple.

h) If mass is not mentioned together with SD, it becomes meaningless and then SD is used stupidly as I hinted in my article. The entry point on buffalo is a 286 grainer in 9,3 caliber. Pushing velocity to 2,400 fps in the big bores (.416 and up) is simply unnecessary and only adds to higher recoil and pressure - that is stupid! My contention is the rule of thumb must stand ... SD should preferably be more than .300 and velocity around 2,250 fps - just like the 404 Jeff gives it to us.

i) So it all depends. Could it be that your system is actually more stupid (irrelevant & non descriptive) than the user that opts for higher SD bullets where appropriate? Is it really that dumb to put more weight behind a bullet's XSA when we go after large animals like buffalo? Look at Katte Katzke's (PH) favourite - the 430-gr Rhino Sold shank bullet at 2,220 fps in the 416 Rigby - it works like the hammer of Thor on buffalo - incidentally the SD is equal to .355 ! Would it be correct to say SD is a figure of merit (FOM), meaning there is some merit in the figure?

In closing, I think every cartridge (small to big), based on its design criteria and pressure limitation has a 'best' combination between mass and velocity for its bore size. The dichotomy we have is that 'ballistic balance' is not always the same as what gives us terminally the best result, especially when we are not shooting mono-metals exclusively.

Ballistics is a journey of discovery.
Chris Bekker

quote:

Originally posted by Gerard:
Which one?

any.. it's immaterial which one you choose...

customer service king!!
jeffe

37.7mm

quote:

Originally posted by Gerard:

BFaucett,
Have a heart. Look at Jeffe's post above. He strings together three unrelated and incomplete trains of thought preceded by an unfounded statement and then you hold me to ransom. You know I like dogs and I have not seen your face so I cannot ID you in a line up..... Can't we negotiate about this....please don't shoot the dog. Pretend you did not read the following.

MD = Mighty Dick
Units of momentum density = Jerk

Where are we going with this?


I am trying to stay out of this CIRCLE JERK!!!

.

So what was the conclusion?

Posting for Chris Bekker:

Which is the most practical measure?

Gerard,

Gerard said ... "One thing has emerged from this thread and that is that Mo/XSA is only a comparative indicator of penetration if both bullets strike similar media and react to the retardation in similar manner. Mo/XSA cannot be used to indicate lethality. It cannot be used to determine what size animal could be taken successfully. In a moment of absurdity someone suggested that my 22 x 64 would not be much use on an elephant despite a quite respectable Mo/XSA number. Ultimately the size of the animal will dictate what level of force we apply and then, some tools with similar numbers will work better than others because they are more effective in delivering the force to the target."

Mr. Bekker said all along that Mo/Xsa is useful measure for penetration, but far from the ultimate measure as penetration ability is but one parameter. That means the search continues for another more comprehensive or better yardstick. To this end you hinted ... "some tools with similar numbers will work better than others " I am curious to know which tools you have in mind? We know it cannot be the very scientific energy formula, for sure. Another formula or index?

Regards

Mehul,
In this case "tools" are the bullets. I do not believe it is possible to put together a formula that will predict with accuracy which one of out of several different bullet/cartridge combinations will be most effective on game. Some things are self evident: I would choose my 375H&H for cape buff rather than the 22x64. With my 22x64 I would not use a jacketed hollow point match bullet for antelope up to 200lbs. We do not need formulae for making these choices.

Debating whether a 404 or a 416 Rigby is best for dangerous game, makes for pleasant banter around the campfire and the outcome of such a debate is really of no consequence.

Where comparisons and formulae are most useful, is when bullet choices confined to a specific calibre is made. The objective would be to optimise the performance of a given cartridge with a specific task at hand. This is where bullets (tools) with similar numbers (Mo/XSA, energy and momentum) could perform in very different ways. A lot depends on how they are constructed and what specific use the manufacturer had in mind. In such comparisons formulae are useful and should always be tempered with the reality of bullet construction.

All jacketed lead core bullets are not created equal and all monometal bullets are not created equal. Stating that Brand X will perform in similar fashion to Brand Y, just because both are monometal bullets or bonded core jacketed bullets, is a mistaken assumption. There is also no need for new formulae to be invented. Everything we need to make the choices already exist.

Just came in on this.

Who is Chris Bekker.........and why do we care?

Never heard of him.

I believe he writes articles for a gun mag or something like that. What amazes me is that this thread is still going, and none of them have ran out of piss for their pissing match! Too funny. Sooner or later they might come to some sense of agreement, or agree to disagree...

quote:

Originally posted by gixxer:
I believe he writes articles for a gun mag or something like that. What amazes me is that this thread is still going, and none of them have ran out of piss for their pissing match! Too funny. Sooner or later they might come to some sense of agreement, or agree to disagree...

Still going gixxer, and a part 2 offspring as well has spawned off farther down........

BigRx

I wish I paid more attention in math in High School because for the most part, they are explaining their equations, but I am still somewhat lost. Not that I really care, but maybe understanding exactly what was on the plate might help me pick a side.

That's o.k, I will stick to using my 375 RUM on Florida deer. I could practically load it with cotton balls and get knockdown power on them.

I wonder what the Taylor K.O. value would be for that. Oh wait, I forgot that somewhere in this thread we disproved the K.O. theory on the basis that a 458 Winmag might out penetrate a 550 magnum, or whatever... Based on sectional density, bullet construction, and velocity(not over 2500fps though).

.

Gentlemen,
For those who came in late, there is some history here. Several years ago Chris Bekker wrote an article published in Sporting Rifles. In mentioning our products, he made several gross errors and I requested corrections of these errors. A protracted debate ensued, during which he continued to make errors and I continued to point them out. Since then he has been sniping at our products and, every time he makes technical errors regarding our products, I have taken him to task for it. I would be perfectly happy if he would ignore our products entirely and refrain from mentioning them ever again.

I welcome criticism and input regarding our products, how else would we grow and improve? I do draw the line when incorrect statements are made that stem from ignorance and/or sloppy journalism. If one ventures into technical writing on a professional basis, the first requirement is accuracy. I warned Mr. Bekker to get his facts straight or get used to my reaction when he does not. I am sorry that some members find this tedious and boring but, with respect, it is your choice to read the thread or pass it by.