quote:

Originally posted by JPK:
Round nose solids do not penetrate nearly as well as flat nose solids but seem to me to hit harder. As distance grows and velocity falls, I would have to strongly favor a FN solid for anything with size to it.

quote:

Originally posted by CouchTater:

quote:

Originally posted by JPK:
Round nose solids do not penetrate nearly as well as flat nose solids but seem to me to hit harder. As distance grows and velocity falls, I would have to strongly favor a FN solid for anything with size to it.

My gut instinct, pardon the pun, is that wound channel diameter must be very proportional to velocity and meplat size. If you consider a RN to be a special case of FN with 0.0001% meplat, in some magical tissue of perfect uniformity the more meplat, the more work done on tissue by a larger meplat, and more loss of velocity as kinetic energy in the bullet is transformed into work done on tissue.

This would imply that a RN performs less work on tissue, and higher velocity through the tissue. On a smaller animal this wouldn't make much difference. On a buff or bigger, maybe a RN delivers more work on tissue deeper in the body where it counts? Versus a FP that transfers a lot of energy in the first foot or two, but is a bit tired when it reaches the off side?

As for the recommended thread, I flipped through it but it seems mostly about inches of penetration and inches of something else...

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quote:

" we noticed that the faster we drive the bullets, the more dramatic and the more frequent were the incidents of one shot knockdowns. With no bullets recovered from game in the initial testing phases, we assumed that the bullets mushroomed and had extremely high weight retention, as that was what our HP range was doing. We also noticed that the softer (easier to expand) we made the HVs, the better they worked at all distances on game. All along we were puzzled by the fact that exit holes appeared to be only slightly bigger than calibre size. Close shots produced bigger exit holes but meat damage was still less than what we expected, given the speeds we were getting.

Then, in fairly quick succession, we were confronted by some very strange facts. We recovered a number of small calibre bullets from large animals where the bullets worked extraordinarily well. All of them were the same shape. The petals were completely torn off and the bullet front was expanded to a virtually flat shape. Weight retention was around 80 to 85 %. Experimentally, we then designed some hard bullets and some soft bullets and went shooting animals.

In every instance where we had double calibre or more expansion with full weight retention, the effect on the animal was less dramatic than with the "soft" bullets that broke down to 80% or so. To add to the confusion, our FN bullets were becoming an unprecedented success. Wound channels from the FN bullets resembled those of soft nosed premium bullets that expand to double calibre and more.

Clearly something was better about the soft HV design and the FN flat nose. For someone like me with forty years worth of input that said "good mushroom, maximum weight retention" it was impossible to figure out. The results were indisputable though, and the HV concept was born. While we designed HV bullets that would go as fast as possible, completely expand in one to two inches, throw off the three petals and then carry on as an expanded cylindrical shape, we searched for an answer to explain why the effect was so dramatic.

The explanation came in the form of an excellent book by Duncan MacPherson - "Bullet Penetration". His research reveals a couple of things:
1. It removes all doubt that the most valuable wound trauma incapacitation mechanism is a single large wound channel.
2. It proves conclusively that the most reliable instrument with which to inflict the maximum amount of disruption was a vertical faced, sharp edged projectile.

The reason why a cylinder shape is so much better than all other is because of the manner in which it displaces the tissue it encounters.

A rounded shape of any description displaces tissue to the sides of the wound channel in the time it takes for the front of the shape to move forwards and be replaced by the full width of the shape, creating a primary wound channel. Although this happens very, very fast, a rounded shape therefore contains a time and distance element that translates to a level of force imparted to the tissue. This makes the tissue continue to stretch away from the bullet path, creating a temporary wound channel, until the elasticity of the tissue overcomes the force and brings it back to the original position. Some of the tissue would have been disrupted and this would add to the total size of the primary wound channel.

A cylinder shape encountering tissue, displaces the tissue to the side vastly faster on a time/distance basis than any other shape. This imparts a far higher force to the tissue, pushing it much further from the primary wound channel, disrupting more tissue beyond the limits of elasticity and ultimately contributing to a much bigger primary wound channel.

Now there was clarity about the FN bullets as well. The HV design was in fact only an HV in flight. A couple of inches after impact, it would resemble an FN bullet.

In practise we see with HV and FN bullets that soft aqueous tissue such as the lungs, liver, brain, large blood vessels and stomach contents suffer massive trauma with HV and FN bullets. Firmer tissue such as meat, heart and kidneys survive much better.

Another point MacPherson mentioned in his findings was that, when the larger temporary cavity included a vital element, such as the liver (or spine in the case of your two shots), the damage to those elements was enough to cause disruption and incapacitation.

The bottom line is that traditional bullets, that depend on a mushroom, may or may not work. In some instances they break up too much and fail to penetrate deep enough, and sometimes the forces are not high enough and they do not expand at all. With HV bullets the worst that can happen is a good mushroom, if speed falls to really low levels. At speeds over about 2600 fps, the petals part company and it turns into a totally reliable mechanism that works in the same manner with monotonous regularity."

quote:

he provides a clear and accurate explanation of why the RN which penetrates substantially less must transfer more of it's energy to an elephant's head than a deeper penetrating FN. Here is a simple example, one 500gr RN I used on a frontal brain shot was found in the neck, not too far from the skull/spine ball joint; one 450 FN used on a frontal brain shot was found a few inches from the elephant's anus. Both bullets had about 5,000lb' of energy at the muzzle and the distance was close for both shots, the difference in striking energy wouldn't have been much. The RN expanded all of that ~5,000lb' of energy in about 40" or so, almost all of that in the head, the FN expended all of the ~5,000lb' of energy over about 96" or so, about a third of that in the head.

quote:

Originally posted by CouchTater:
All this is maddening! I want a single algebraic equation that accurately predicts terminal effect, and I want it now!

At least in aerodynamics, a round nose object will disturb the air less than a flat nose object (both would be called "bluff bodies" by a theoretical aerodynamicist). So all else equal, I cannot see how a RN performs deformation work faster and loses KE faster than a FN, unless the RN is yawing more.

If a RN was precessing all the way from entry, I can see how that could generate a bigger wound channel. That might explain some of the field observations that RNs go off-course more often; a RN doing the precession dance could hit bone or a much denser flesh type and sorta change course based on the angle of the bullet when it encountered the bone or whatever.

Some extremely rich guy needs to forego a few African trips, and set up a lab with a super high speed camera and a gelatin setup with two blocks of substantially different gel. He could have the interface plane be perpendicular to the axis of bullet flight, and then repeat at say 45 degrees. 10 shots of FN, 10 shots of RN. Bound to get at least one or two good videos.

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quote:

Originally posted by 416Tanzan:

quote:

he provides a clear and accurate explanation of why the RN which penetrates substantially less must transfer more of it's energy to an elephant's head than a deeper penetrating FN. Here is a simple example, one 500gr RN I used on a frontal brain shot was found in the neck, not too far from the skull/spine ball joint; one 450 FN used on a frontal brain shot was found a few inches from the elephant's anus. Both bullets had about 5,000lb' of energy at the muzzle and the distance was close for both shots, the difference in striking energy wouldn't have been much. The RN expanded all of that ~5,000lb' of energy in about 40" or so, almost all of that in the head, the FN expended all of the ~5,000lb' of energy over about 96" or so, about a third of that in the head.

Any chance that the RoundNose in the example tumbled, veered off course, or richocheted? My understanding is that the roundnoses couldn't keep up with the flatnoses in the wetpaper medium because they veered off course and wobbled.

Also, some of the evidence in sources like Rathcoombe Shooting Holes in Wounding Theory pointed to increased damage with flatnoses, which means an increase in energy dump. Elmer Keith was pretty adamant in his day about wadcutters.

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quote:

Buff seem pretty immune to knock down, knock out or "thump" effect, or whatever you want to call it.

quote:

Originally posted by JPK:
416Tanzan,

An interesting note on a FN on a buff. I shot a buff front on with a Woodleigh solid (we encountered the bull while on elephant tracks) and he spun and was running off down hill almost directly away when I shot him with the second barrel. The bullet, a North Fork 450gr FN solid at 2,220fps, entered his back and spine above his tail and exited through his boss. He dropped like a stone.

Here's a photo, you can see the blood where the bullet entered and see the exit hole in the right boss as you look at the photo. The exit hole is the dark spot on the boss, laterally about 1/2 way between his eye and the center of the boss between the halves.


The bull was aggressive, and we discovered why. His nuts were full of maggots from a wound probably inflicted by another buff hooking him.

JPK

quote:

Originally posted by JPK:

The bull was aggressive, and we discovered why. His nuts were full of maggots from a wound probably inflicted by another buff hooking him.

JPK

quote:

Originally posted by Nakihunter:
What about the dimpled nose of the Woodleigh Hydrostatic? The CEB FN also has the bands which should result in considerable drag compared to a Woodleigh solid that only has the canelure.

I wonder what Michael458 would have to say on the subject.

quote:

Originally posted by CouchTater:
Cape buffalo bull with aching balls? Man, that's the stuff of nightmares.

----

So let me try to summarize;

rank order of real world penetration:
1- FN solid
2- RN solid
3- spitzer solid
this is ignoring the possibility of extreme spin rates or fin stabilization.

rank order of real world early wound channel diameter (lets say entrance side of body):
1- RN solid
2- FN solid
3- spitzer solid

rank order of real world late wound channel diameter (lets say exit side of body):
1- FN solid
2- RN solid
3- spitzer solid

So if you're shooting smaller or softer game, say lions, with a caliber in the 40s, you might go with a RN-FMJ for faster wobbling/tumbling and maximum wound channel on the near side.

If you're head-shooting elephants with a caliber in the 40s, you might go with a FN-FMJ to ensure more than enough penetration and no surprises due to bullet track veering off into an oddball direction.

Everyone agree? (I crack myself up sometimes)

There is the question of why folks who luv the cast bullets generally prefer FN designs. I can make a coffeeshop argument on that. Most cast bullet hunters use slower big bores. Usually a short, fat FN, so bullet aspect ratio is relatively low and thus a RN of equal weight will be terminally stable and not produce enough wound channel (not to mention really excessive penetration).

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quote:

Originally posted by Santa Claus:

quote:

Originally posted by Nakihunter:
What about the dimpled nose of the Woodleigh Hydrostatic? The CEB FN also has the bands which should result in considerable drag compared to a Woodleigh solid that only has the canelure.

I wonder what Michael458 would have to say on the subject.

Your My ignorance is showing.

Santa Claus

quote:

Originally posted by CouchTater:
Cape buffalo bull with aching balls? Man, that's the stuff of nightmares.

----

So let me try to summarize;

rank order of real world penetration:
1- FN solid
2- RN solid
3- spitzer solid
this is ignoring the possibility of extreme spin rates or fin stabilization.

quote:

rank order of real world early wound channel diameter (lets say entrance side of body):
1- RN solid
2- FN solid
3- spitzer solid

quote:

rank order of real world late wound channel diameter (lets say exit side of body):
1- FN solid
2- RN solid
3- spitzer solid

quote:

...
If you're head-shooting elephants with a caliber in the 40s, you might go with a FN-FMJ to ensure more than enough penetration and no surprises due to bullet track veering off into an oddball direction.

...

There is the question of why folks who luv the cast bullets generally prefer FN designs. I can make a coffeeshop argument on that. Most cast bullet hunters use slower big bores. Usually a short, fat FN, so bullet aspect ratio is relatively low and thus a RN of equal weight will be terminally stable and not produce enough wound channel (not to mention really excessive penetration).

quote:

Originally posted by JPK:

A RN will penetrate more than adequately to reach the brain or the skull/spine joint before it turns to travel base first. When it does turn, it does it begins in or near the skull, dumping all of the energy for maximum effect on the elephants if the brain is missed. This often results in knocking down the ele or even knocking it unconcious, buying time to make a killing second shot. RN's do not veer in elephant heads, and their incidence of veering in elephant bodies appears to be no worse than FN's. (Though they do turn to travel base first.) What holds true for the 458wm, also hold true for the 416's, 404J and the 450/400's, and also seems to hold true for the 375H&H.

A FN will penetrate more than adequately but expends its energy over a greater distance and time, not much expended in the skull or near. But the penetration may be needed for a second or subsequent shot, and it is preferred for its penetration for those shots.

JPK

quote:

Originally posted by ALF:
ledvm:

But then I have it on very good authority that the elephant skull in the living animal is far from a homogenous solid structure.

(Source: The skull and mandible of the African elephant (Loxodonta africana).
van der Merwe NJ, Bezuidenhout AJ, Seegers CD.
Onderstepoort J Vet Res. 1995 Dec;62(4):245-60.)

Depending on the path chosen for your projectile it will after initially passing through the muscle of the upper trunk encounter in terms of penetration depth mostly air interspaced by relatively thin barriers of diploe lamellar bone lined with serous respiratory epithelium, until it encounters the brain. In terms of density the biggest barrier is not the bone but the trunk muscle. That has the greatest potential to induce enough drag to act as a unbalanced force on the bullet.



The point I wish to make is that if we look at the behaviour of a ogived projectile in a dense homogenous target such as gelatine or pure muscle the wound profile would have it that there is an initial narrow channel phase of penetration of varying distance dependent on the shape of the projectile, the distribution of mass of the projectile, the sectional density of the projectile.

In this phase the dimension of the PC will be dependent on and will have an equivalence to the amount of form drag that the projectile induces.

The RN will by virtue of its smaller Cd induce less drag than the cylinder with its larger Cd.
until the angle of attack starts growing for the RN, once this process is initiated the Rn will rapidly overturn.

So in effect a RN may for a variable distance do very little damage, penetrate straight until drag and unbalanced forces overturn it.

J Hand Surg Am. 1992 Sep;17(5):971-5.
Hand and forearm injuries from penetrating projectiles.
Fackler ML, Burkhalter WE.

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In the context of thses discussions...I think we trying to figure out the projectile with the least amount of variance in highly variable situations ("the elephant skull in the living animal is far from a homogenous solid structure").

quote:

Originally posted by ALF:
Yes Lane! Variable based on the configuration of RN you are shooting. Not all RN's are created equal!

First off you could go from a true hemispherical RN all the way down to a very long slim ogived RN and then to add there is the after body length. Add to that whether the after body has a Flatbase or a boat tail and when selecting the boat tail the angle of the boat tail and its shape. All contribute to Drag and ultimately how the RN is going to behave in the target.

There is ample proof of this fact when looking a high speed water entry behaviours of projectiles fired into water, gelatine or ballistic soap.

If the model we choose to describe the behaviour of our bullet to is based on hydrodynamics then this is what is important.

What I cannot understand is that all seem to have some grasp of why we shave to spin bullets ( or perhaps they do not really understand why? ) to get them to the target pointing forward and in the same place but sadly once the bullet transitions from air to target suddenly all this wisdom gets discarded.

The only thing that changes when the bullet transitions from air to say a fluid or a gel like Gelatine is that the density of the target in which the bullet finds itself changes and with it the magnitude and type of drag based on the design characteristics of the bullet. Why this is so difficult to understand I cannot fathom or why for some or other reason folks try and assign behaviours to the bullet that simply have no physical basis.

To give you an example: There is this insistence and belief that somehow barrel angle of twist has anything to do with projectile effectiveness in a dense target, other than getting it to the target point forward. There is no basis for this because the premise to which gyroscopic stabilization works is negated by the high density of the target.

An insistence that somehow the relationship between mass and the projected surface area as expressed by the concept of sectional density suddenly is no longer applicable when using so called modern bullets.

GS custom went so far as to actually publish a whole article on their website claiming this ! What they did was to deny the very laws of Newton and Euler. This is pseudoscience at its worst !

If you have a body where mass is distributed within a form and having volume that body interacts with other bodies through a representative surface area.

This concept is integral to our understanding of how the projectile is going to interact with the target. This is central to our ballistics system, whether the projectile is a FN cylinder, a sphere and RN or ogived projectile or even a chunky body deriving from the break up of the projectile before or after target entry.

Then off course we have the target itself, somehow everyone claims the validity of results of those so called tests and no one but no one has actually questioned the impact of the choice of target and what influence it may have on the outcomes of the tests.

It does not take a rocket scientist to realize that stacked paper albeit wet poses a huge problem for any tester or test. The simple fact that you can poke your finger into the surface of gelatine and cannot do it to a telephone book is ample evidence of the problem at hand.

A simple web search into the physics and mechanics of a field of engineering called paper science will yield enough information to show exactly how special this medium would be as a target.

The very use of a simple desk edition of a hole punch used to punch holes in paper is a perfect example of the problems facing anyone wanting to perforate a whole stack of this stuff.

And yet in all of this everyone raves about the so called results and how these are indicative of anything other than shooting at paper ? The tests do not even address the problems that arise from the "internal " behaviours of the medium itself let alone give us information she the results are to be used a comparison to other totally dissimilar target mediums.

I attend a lot of lectures and seminars on injury and trauma and deliberately seek out symposia on gun shot trauma.

They typically would start off with some dude standing up and showing statistical data on gun shot injury in the US, this is the common theme, and then to follow some conclusion that guns need to be banned as counter to the problem of gunshot injury.

This is off course a flagrant "Perversion of Science" just as claiming that spoons are the cause of obesity.

We as shooters take exception to this premise and if not we should because it is simply not true, guns do not kill, people, there is no scientific basis for to prove the contrary.

In the same spirit then if we as shooters and hunters put forth opinion of how projectiles work to put down or targets why would we propose or believe in pseudoscience.

Personally I take no sides on whether this or that bullet is better, I take no sides in claiming this product or that product line is better. If you want to shoot a elephant with a RN or a FN it matter little to me. Wether its Michaels bullet, or Gerhards bullet, Woodleigh, NF or even a lead slug

All I'm am interested in is that when a claim is made it be done to sound scientific argument and that is what i am prepared to debate.

quote:

Originally posted by ALF:
Lane:

This is exactly my point!

Simulation testing is a science in itself and anyone who publishes results on this clearly understands that they are simulating projectile parameters and behaviours. So if you were using paper you could claim this is what my bullet does in paper, however there is a catch, if you specify for a parameter tested then you have to test for that parameter and you have to be cognizant of whether the simulant is appropriate for testing for that parameter.

Paper in terms of behaviour is complex because it is, and behaves like a composite stacked woven material..... look at it as the poor man's Kevlar ! This is not the appropriate medium to make any assumptions on regarding basic premises and rules.

For one this stuff does something that tissue does, it stacks in front of the penetrator and the stack or plug becomes a missile in itself. As a tester you are now faced with the virtually unsolvable task of dealing with a stack of compressed paper that gets pushed ahead of your penetrating bullet. Not only that if the bullet is a hollow point paper may plug the cavity and alter the behaviour of the projectile.

Gelatine is a colloidal gel, it is not tissue not by a long shot, it shares some common mechanical properties of some tissues but not all. So as long as the tester and test design acknowledges this difference.

The most studied shape in penetration mechanics and wound ballistics is the smooth steel sphere for any number of very obvious reasons.

The problem is that because of the complex nature of fluid and solid mechanics as well as the list of variables that significantly impact any test, home or hobby testing is virtually useless.

Whilst we all are what I like call "bullet diggers" those dudes who are more interested in finding the bullet and looking at the gory part of the carcass once shot than the actual trophy
Our observations are likely no more than anecdotal musings and ponderings of what really went down.

As to 456H&H's question regarding the "best nose shape" and why the RN may out penetrate the FN in a elephant skull.

The most efficient rigid penetrator shape is the ellipsoid ogived RN projectile shape . There are any number of sources to prove this.

having said that I can see it now: ! "yes but Micheal's testing shows otherwise ! " yes it does, but fact is that in terms of rigid body penetration in all manner of targets this shape has been proven to be the most efficient shape for depth of penetration. So why then Micheal's valid observation regarding the FN?

There is one provision though that is unaccounted for and this is very important, critical in fact. The RN projectile has to remain nose forward, no angle of attack ! And this is why the FN wins !

The RN does not necessarily need to overturn, just the fact that its posture may not be spot on true to direction of travel will change and add drag to the equation.

quote:

Originally posted by ledvm:
Alf,

I will add though that every thing I have shot with the flat nose monolithic solids...they have performed similar to what Michael has hypothesized.