I know a guy who believes that velocity is everything when it comes to bullet penetration. Utilizing standard cup and core bullets, his assertion is that, even if a bullet comes apart, the pieces will continue doing damage and out-penetrate the same projectile launched at a slower speed.

I argue with him that velocity is the enemy of penetration, especially with cup and core bullets, and that a bullet launched at a speed that does not cause it to turn inside-out will out-penetrate a bullet that does.

For example: I believe that a standard Sierra 7mm bullet fired from a 7x57 at 2500 fps will out-penetrate the same bullet fired from a 7mm RUM at 3300 fps. In fact, I've seen research on this very subject, but I can't find it through a web search.

Anybody know where I can find this info?

Is he the sort that is immune to Physics?

I mean, will a scientific explanation suffice or are you looking for a video or photos of an experiment or something like that?

Video would be nice, however a simple magazine article on the subject would be okay.

Here's a video I found that tests a 7mm, 160-grain Woodleigh fired at two velocities: one a 7mm Rem. Mag, and the other a 7x57.

The 7x57 won.

http://www.youtube.com/watch?v=eLfDYon92n0

Obviously he hasn't outgrown the Weatherby philosophy of kinetic energy. The theory goes that if you drive a bullet fast enough, you don't need to figure distances, nor practice marksmanship since the bullet will rise out to about 300-400 yards. Any hit anywhere will blow the animals heart apart. Indeed, I have heard that stated.

You can even use a bonded bullet that doesn't come apart and most of the time the slower bullet will still outpenetrate the faster one.
This is because the faster one expand to a larger diameter and because of this slow down and stop earlier.
You can just do the test with one gun and shoot into some ballistic gel at different distances.

Looking for info:

Here is a start:

1. Wound ballistics: Basics and Aplications: Coupland Knuebeuhl and Rothchild Springer Verlag : (Currently in press and available.)

2. Wound Ballistics and the scientific method: Knuehbeuhl and Selllier ( out of print but copies are available on the second hand market) This is the gold standard !

3. Janzon B (1983): High Energy Missile Trauma – A Study of the Mechanisms of Wounding of Muscle Tissue, Doctorial Thesis, University of Göteborg, 1983

This little book is basically a short version of Knuebuehl in terms of content and context and bears the same hallmark theories promoted by the Fackler group in the USA.

4. Wound Ballistics: James Coates and James Beyer Office of the US Surgeon General. This a historical great with a lot of information.

5. Scientific Foundations of Trauma. by Cooper: Butterworth-Heinemann, Oxford 1997. This book is out of print but the gunshot chapters are by Janzon and his co- authors. This is a very good book in terms of basic science. There is a whole chapter on missile tissue interaction.
6. Janzon B, Berlin R H, No- rdstrand I, Rybeck B, Schantz B (1979): Drag and tumbling behaviour of small calibre projectiles in tissue simulant. Acta Chir. Scand., Suppl 489:57-70, 1979.

7. Dahlgren B, Berlin R H, Janzon B, Nordström G, Nylöf U, Rybeck B, Schantz B, Seeman T (1979): The extent of muscle tissue following missile trauma one, six and twelve hours after the infliction of trauma, studied by the current metrhod of debridement. Acta Chir Scand, Suppl. 489, p 177, 1979
Janzon B (1997):

The Supplement of the Acta Chir Scand, Suppl. 489, 1979 is a complete collection of very good papers on the science of gunshot wounds.

To be honest, Alf, I am not sure this guy could make it through one paragraph of and academic piece.

I was kind of looking for something more along the lines of an article from Guns and Ammo, Shooting Times or Rifle Magazine. You know, something simple, like "This 140-grain 7mm Sierra Game King was fired at 2400 fps and penetrated ballistic gel 32.43 inches: On the other hand, this 140-grain, 7mm Sierra Game King was fired at 3350 fps and penetrated ballistic gel 2.12 inches before blowing all to Hell!

Moral of the story? Speed kills (penetration, that is).

Oh ok then ?

here is the dummy version:

You dive into your pool at home and you have no problems you do the same from the Golden gate bridge and suddenly you are in a whole lot of hurt, same water, same person only difference is the impact velocity. The water became "harder", as "hard" as concrete in fact, enough to break every bone in your body ! it is the resistance to penetration that increases in exponential fashion as velocity increases. Simple enough?

That was great!

Well done Alf. That is the perfect analogy -- painful to think about -- but perfect!

By "his" theory, a hollow point/varmit bullet would also perform the same as a cup-and-core bullet or a premium bullet. By the same logic a FMJ bullet would also suffice for varmits.

I think he needs to test his theory on himself -- that would help remove some recessive genes out of the human gene pool.

Barstooler

This will require reading of the first two paragraphs for the opinion. Then comes the explanation.
http://www.rathcoombe.net/sci-...allistics/myths.html

quote:

Originally posted by GAHUNTER:
Here's a video I found that tests a 7mm, 160-grain Woodleigh fired at two velocities: one a 7mm Rem. Mag, and the other a 7x57.

The 7x57 won.

http://www.youtube.com/watch?v=eLfDYon92n0

Be nice to know at what distance they shot into test media, was it 10yd?,100yd?,150yd??
Impact velocity interests me more than muzzle velocity.

If those tests were done near the muzzle, then 7mmMag160WL 2900mv could prove to be the better penetrator when attempting to bust an Elk or Kudu at 200yd[2500fps impact vel.]

or are we led to assume the lower velocity/lower momentum 7x57 will still penetrate better all the way out to 200yd?

Maybe he should have done some comparative tests for different distances,

Oh shit here we go again:

So you want to test penetration as a function of velocity: no more no less, just these two factors, velocity vs penetration.

( important to the validity of the test the target has to be of visco-elastic mechanical property)

The test:

You take a standard projectile, round ball made of steel, ( round because that negates tumbling, steel because under 4000 fps it should not deform or fragment ) and you fire that into the test medium at varying velocities and you measure.

Two things happen, as the velocity goes up the penetration depth gets less and less, and secondly the size of the temporary cavity increases.

As the Temporary cavity is a direct function of drag the size of the cavity increases ( drag being a measure of resistance the projectile experiences)

So this test proves two related facts, as the velocity increases the projectile experiences more drag and thus the penetration depth decreases.

Think you need to contact Larry the cable guy.

Alf,
your non-deforming steel ball relates how to a 7mm 160wl soft that will exhibit variation in deformation at different impact velocities?

NorthFork softs apparently reach max. expanded dia. at 2100fps impact velocity,
now,the same bullet with same expanded dia. & same retained weight, but impacting with more speed and momentum[anywhere between say 2200-2500fps?] ...will penetrate less than the 2100fps impacting bullet?

Alf,
You are right. The test is absolutely true for bullets that do not deform and have round shapes presented to the direction of travel.

Different shape bullets that do not change shape also react differently, one from the other. though. Bullets that expand in haphazard fashion are unpredictable and unreliable.

One thing is sure, this is not a simple subject and one that cannot be explained simply. If the inquiring mind is not prepared to listen to the technicalities, that inquiring mind must accept the facts as presented by those who are prepared to explain.

Here is a video I made of a 7mm penetration test.

The left projectile:
160 Woodleigh PPSN muzzle velocity 2,374

the centre:
154 Hornady Spt muzzle velocity 2,461

and the right:
160 Woodleigh PPSN from a 7mmRM 2,908fps

Impact was at 100 yards.

http://www.youtube.com/user/Tophet1?feature=mhee

quote:

Originally posted by Code4:
Here is a video I made of a 7mm penetration test.

The left projectile:
160 Woodleigh PPSN muzzle velocity 2,374

the centre:
154 Hornady Spt muzzle velocity 2,461

and the right:
160 Woodleigh PPSN from a 7mmRM 2,908fps

Impact was at 100 yards.

http://www.youtube.com/user/Tophet1?feature=mhee

Code,

Your viedo is already linked in this thread. Good job, BTW.

Trax:

How does it relate: Principle !

You have established the Principle, now expand by adding the variability of a deforming projectile and see what happens.

There are numerous bullet advertisements showing the degree of deformation of the projectile as a function of impact velocity.

From this then valid predictive calculation formulae such as the universal penetration formula of Young whereby penetration of a solid target by projectile can be calculated.

This includes eroding, deforming or non deforming projectiles.

But you cannot blame this fellow for thinking this.

After all one of the fathers of modern ballistics Benjamin Robins the Gentleman who gave us the Ballistic pendulum which solved one of the original questions of classic ballistics namely the prediction of velocity also believed as he did.

Robins in 1742 published New Principles in Gunnery and on page 152 he states that the penetration depths of a projectile into a dense target is proportional to the velocity and further that the resistance afforded by the target is uniform?

This after firing lead balls at varying velocity into solid elm.

Was Robins right or wrong?

After all he was obvsiously a very astute observer and his theory on this was actually seen as correct for almost 200 years.

Well he was actually both right and wrong !

Right because his observation related to the elm only. The wood ( we must assume dry wood) showed mechanical properties exactly what we would espect from a "dry solid" ie resistance to penetration unrelated to the impact velocity.

Wrong in that if Robins's test were to include a target with primarily visco-elastic properties he would not have been able to come to this conclusion.

I play with this in the off season...

what I found as simple logic would also tell you...

what you have 1 item hitting a second item, both have X amount of integrity...

it is going depend on how much integrity Item A has ( the bullet), vs how much its velocity and the integrity of what it hits offers in resistance...

hence why premium bullets are needed for fast stepping magnums...

hence why ballistic tips open up better at lower speeds...

hence why sectional density plays a big part in regular bullets vs faster and lighter sectional density...

for example, I have fired a 175 grain Partition at high speed ( 3000 fps), from a 7 Mag into a test media... and then fired a 175 grain Hornady RN at an MV of 1800 fps.. the test media was shot at 100 yds....

which one do you think penetrated further?

If I can remember it all correctly, and you want to boil it all down to its most simplistic form all else being equal....

The faster you push an object through any medium, the faster it slows down due to friction. Greater velocity equals greater friction which in turn increases rate of change.

ALf's steel ball test does exactly that. It measures penetration as a function of velocity.

When you start talking about terminal performance there are many more factors to consider such as bullet construction and impact velocity/ location.

As far as picking a bullet to hunt with....Greater friction = greater bullet deformation. Adjust your projectile selection accordingly.

Here's the statement made on another forum that began this conversation. The writer is responding to my assertion that the higher a rifle's velocity, the more the need to use premium, controlled expansion bullets(like the triple shock).

"...First off, velocity is not the enemy of penetration, that's a myth....sorry, but that's the first myth. Velocity is a key and necessary component to penetration. Loss of mass and weight is the enemy of penetration. It depends entirely upon bullet construction and the density of the target. In ballistic gel, I guarantee you that with equal bullets, the one travelling the fastest will penetrate furthest. At the same velocity, with two bullets of the same design and construction and different weight, the heavier one will penetrate furthest. Simple physics. More speed, more momentum, more penetration. Same speed, more weight= more penetration. When you start throwing bone and that sort of thing into the equation, then you start running into the possibility of bullets coming apart and bullet deflection, BUT NOT NECESSARILY. A whole bunch of factors come into play. If it doesn't hit a big bone and fragment, a good cup/core bullet will finish it's expansion within 3 or 4 inches of penetration and then continue to drive through dumping energy (and weight) as it sheds velocity. The more velocity it has and the more weight it can retain, the further it can drive through if it doesn't come completely apart. A monolothic bullet has a much, much better chance in that respect...."

GAHUNTER:

Perhaps a short discourse in drag mechanics would be in order at this point.

Velocity is definitely the "enemy" of penetration when it comes to target materials of primary visco-elastic mechanical property, in fact it's contribution to drag stands in a exponential relationship.

Double the impact velocity and the force of retardation on the presenting part of the projectile quadruples , treble the velocity and the force of retardation goes up 9 fold. This concept of drag actually infers how much energy the projectile is shedding to the target per unit of distance penetrated. if the drag is low the transfer of energy is low, if drag is high the transfer is high.

Of the oldest tests done in terms of terminal ballistics it that of comparison of penetration as a function of varying velocity.

Benjamin Robins did it in 1742, not to determine penetration in living tissue per se but as a determination of the effects of drag in air so as to calculate range of a projectile and more importantly as a method of determining what manner of shot need to be used to breach fortifications.

Euler the great German mathematician translated Robins's work into German, added his own notes and this rendition was then later translated back to english. The Eularion method still used today in calculations concerning penetration.

French and Callender two US Military Surgeons conducted exhaustive testing on missiles of varying shape and form to establish principles regarding penetration and the nature of wounds produced by penetrating missiles and projectiles.

The relationship between drag and velocity outweighs any other single factor hence the fact that drag is directly proportional to the value of impact velocity squared.

No other single factor ie mass or the cross sectional reference area of the presenting part of the projectile in direction of motion carries this much weight in the dermination of the force of retardation.

Not only is the contribution of velocity important to drag it is central to our understanding of how a wound is created.

The ability the try and calculate, predict and explain how wounds are created has at it's root the assumption that drag force is directly proportional to the square of the impact velocity, direcly proportional to the mass of the projectile and inversely proportiional to the surface area of the presenting part of the projectile. Of these 3 factors velocity carries the biggest contribution in the drag equation.

And as a subject the concept of drag and energy transfer and how it relates to the phenomenon of the temporary cavity is the must studied entity in the formation of a wound.

Many here proclaim that wounds are not created by a bullet's kinetic energy but by some other manner, they are flat wrong!

It is all about energy and nothing else.... when all is said and done it comes down to two inter-related factors, how much potential energy did the projectile have at the time of impact and what happened to that energy in the penetration proccess;

Or put another way what did the target do with the energy it recieved from the projectile in it's passage. E = 1/2 mV>2

The wound, its behaviour, size, depth and biology is all determined by the reaction of the target to the reciept of mechanical, heat and noise energy. ( heat and noise being negligible in magnitude)

Its not how much it recieved per se but how did it react to that gift of energy. ie it comes down to the biomechanical properties of the target.

And just to add a hair to that...

As mass doubles, energy doubles. As velocity doubles, energy quadruples.

quote:

Originally posted by Trax:

Maybe he should have done some comparative tests for different distances,

If I had the time I would love to do that test and it would be very interesting to see the results at say 50, 150 and 200 yards.. Impact velocitys can be determined with a simple balistics program now I have supplied the MV. I ran that test to confirm or deny observations in the field. I can share some facts I have learnt in the field.

7x57
175 Woodleigh PPSN mv 2,340 fps range 250 paces did not expand on camels.
175 Woodleigh PPSN mv 2,340 fps range 30 paces one was observed to take out a 6" section of off side rib.
140 Sierra SptBt mv 2,780 fps range 120 yards classic side on presentation. Expanded violently and blew apart inside a Red Stag.

7mmRM
160 Woodleigh PPSN mv 2,908 fps range 130 and <130 paces expanded V. quickly on camels and did not exit or reach vital organs on rear raking shots. Neck shots then needed. (Hence the test on medium to confirm or deny)

quote:

Originally posted by Code4:
7x57
175 Woodleigh PPSN mv 2,340 fps range 250 paces did not expand on camels.

7mmRM
160 Woodleigh PPSN mv 2,908 fps range 130 and <130 paces expanded V. quickly on camels and did not exit or reach vital organs on rear raking shots. Neck shots then needed. (Hence the test on medium to confirm or deny)

Ok ,lets work with what info you do have:

Did the unexpanded 175wl exit at 250 paces?

How did the penetration of the two above compare on broadside or raking/angled shots?

Show me the Car Trax....is more a troll than anything else.. and deserves the like wise attention one gives a troll...

Seafire/B17G:


Out of respect for the hunting-shooting parts of AR, most members on this forum have the maturity and sensibility to keep what goes on in the ARPF in the ARPF. Maybe you will learnt to do the same some day.

quote:

Originally posted by seafire/B17G:
Show me the Car Trax....is more a troll than anything else.. and deserves the like wise attention one gives a troll...

Already worked that out but thx anyway mate.

If a bullet has the same weight and frontal diameter it will penetrate more at higher velocity. Something like a nosler or barnes will generally penetrate more at higher velocity while a sierra probably will not.

Lou

quote:

You take a standard projectile......... you fire that into the test medium at varying velocities and you measure..... as the velocity goes up the penetration depth gets less and less

quote:

If a bullet has the same weight and frontal diameter it will penetrate more at higher velocity.

Both cannot be right, they are direct opposites.

I think the difference is previous poster said with standard projectiles penetration may be less as velocity goes up, which I agree. I am referring to bullets that have a similar final shape over their velocity envelope. A nosler's final shape will look pretty similar whether impacting at 2400 fps or 3000 fps. A standard bullet most likely will not. Hence, my comment should have been so long as terminal mass & diameter are the similar... The caveat is if you start one of these expanding bullets so slow they do not expand they many penetrate more than higher velocity where expansion starts since there is small frontal diameter/resistance.

Lou

quote:

Originally posted by marshmandan:

The faster you push an object through any medium, the faster it slows down due to friction. Greater velocity equals greater friction which in turn increases rate of change.
ALf's steel ball test does exactly that. It measures penetration as a function of velocity.

That does not necessarily mean higher impact vel. results in less penetration.

I watched a physics show where there dropped a metal ball/sphere from a certain height into plasticine, exhibiting a certain amount of indentation/penetration.

When they increased impact vel. of the ball by doubling the height of drop[ from 12" to 24" IIRC], penetration did not double,
...it actually near quadrupled.

No, plasticine, is not a great simulator of the biomechanical properties of living tissue/bone, but neither is a stack of cardboard,plywood,ballistic gel, wet phone books or water jugs.
- and neither is a non-deforming ball anything like your typical irregularly deforming hunting bullet.

However, people will continue to use such artificial test mediums to determine[for purposes of hunting] such things as penetration,mythical notions like 'hydrostatic shock", stopping power and lethality of a projectile.

If the actual results on game were not enough to convince me of a bullets behaviour/performance/effects on game,..I don't see value in then going back to the lab to prove or confirm anything in an inferior artificial test medium.
Its a bit like releasing a drug on humans and after your findings, getting the bright idea to see if you get the same results in lab rats.

Trax:

Not to call you out on this ball dropping experiment but:

Assuming the target material was in fact Plasticine the result of your observation suggests that Plasticine exhibits shear thinning behaviour ..... as you have observed, i.e. a quadruple increase in penetration relative to an increase in impact velocity.

I question this because true plasticine is not shear thinning it actually is the opposite but for all intents and purposes one can say resistance to penetration in plasticine is unrelated to penetration velocity.

The important missed factor is the mechanical behaviour of the target and it's resistance to penetration. The old two way street jig !

Many shooters make the common mistake of looking at one way of the traffic only i.e. that of the projectile when comparing behaviour such as penetration, they fail to account for the effects of the behaviours of the target to the penetration.

Alf,
the experiment was real,but maybe it was infact not real plasticine.

however the post I quoted/responded to, stated any test medium.

Clearly an increased speed-faster moving projectile will penetrate further in a shear-thinning medium than it will into a shear-thickening medium, yes?

and your correct,
an important and often ignored factor is the bio-mechanical nature/behaviour of a particular target and it's resistance to penetration.

Plasticine is often used in the testing of specific ballistics effects such as non penetrating munitions or the testing of body armour.

Non penetrating munitions are baggies, rubber bullets and munitions used in crowd control.

The plasticine indentation is used to measure the effects of such munitions, the same applies to the testing of ballistic defeating materials.

As such the indentation behaviour of plasticine has been studied to validate it's use.

quote:

Originally posted by Trax:

quote:

Originally posted by marshmandan:

The faster you push an object through any medium, the faster it slows down due to friction. Greater velocity equals greater friction which in turn increases rate of change.
ALf's steel ball test does exactly that. It measures penetration as a function of velocity.

That does not necessarily mean higher impact vel. results in less penetration.

I watched a physics show where there dropped a metal ball/sphere from a certain height into plasticine, exhibiting a certain amount of indentation/penetration.

When they increased impact vel. of the ball by doubling the height of drop[ from 12" to 24" IIRC], penetration did not double,
...it actually near quadrupled.

No, plasticine, is not a great simulator of the biomechanical properties of living tissue/bone, but neither is a stack of cardboard,plywood,ballistic gel, wet phone books or water jugs.
- and neither is a non-deforming ball anything like your typical irregularly deforming hunting bullet.

However, people will continue to use such artificial test mediums to determine[for purposes of hunting] such things as penetration,mythical notions like 'hydrostatic shock", stopping power and lethality of a projectile.

If the actual results on game were not enough to convince me of a bullets behaviour/performance/effects on game,..I don't see value in then going back to the lab to prove or confirm anything in an inferior artificial test medium.
Its a bit like releasing a drug on humans and after your findings, getting the bright idea to see if you get the same results in lab rats.

You're right, it does not necessarily mean less penetration, and its been well over a decade since I had any fluid mechanics in school but based on what I remember I believe my statement to be valid. That said Alf uses the term drag in a more correct manner than I did the word friction while trying to keep it simple.

Dropping a ball two feet is a very poor comparison to a bullet at best. It barely demonstrates free fall acceleration. Did it even break the surface or merely dent it?

I agree that a non-deforming projectile is not the same as a deforming one, but its really hard to test more than one variable at a time and draw any kind of statistically valid conclusion.

The biggest problem I see trying to find a bullet that performs over a wide variety of velocities. Too high a velocity and things tend to come apart, too low and not enough expansion occurs.

[QUOTE]Originally posted by marshmandan:


Dropping a ball two feet is a very poor comparison to a bullet at best. It barely demonstrates free fall acceleration. Did it even break the surface or merely dent it?

I don't view it as a comparison, I see it as a simple demonstration of a principle. But if you feel it does not really count for anything on this subject, then please tell me,what is the minimum[or correct] impact velocity required to correctly demonstrate the principle?

I agree that a non-deforming projectile is not the same as a deforming one, but its really hard to test more than one variable at a time and draw any kind of statistically valid conclusion.

We can go about attempting to demonstrate/prove all sorts of principles,laws of physics,artificial test medium and/or projectile impact reactions,....but what matters to me most is how the hunting bullet I may choose to use will perform in game.

The biggest problem I see trying to find a bullet that performs over a wide variety of velocities. Too high a velocity and things tend to come apart, too low and not enough expansion occurs.

Lets use the NP as a bench mark. Bonded A-Frames of same cal. initial weight and higher retained weight [and larger expanded cross sectional dia] have proven themselves to penetrate less than the NP when fired into the same animal from the same rifle.
Both bullets went through the vitals but the NP made it further toward the undersurface of the skin on the far side. Less bullet actually travelled further.

Other bullets, like GS-Custom, will after shedding its front section [at HV] typically retain more weight than a NP of equal cal. and initial weight, and may also have a smaller cross sectional area....the GSC will also reliably expand at lower vel. than the NP.

Guess it all depends what kind of performance one desires/requires.

As we are discussing drag as a phenomenon in penetration mechanics I stand directly opposed to some assertions made here on AR on the topic of FN solid projectile behaviour.... I will explain why:

The proponents of the use of FN projectiles claim two behaviours:

First they proclaim bigger trauma per unit distance penetrated in target than an equivalent RN bullet and secondly they promote the idea of deeper penetration than the equivalent RN bullet.

The two sadly are mutually exclusive when comparions are made to ogived projectiles.


The reason I state this lies in this concept of drag and the gift of energy to the target as consequence of the drag.

When comparing the coefficient of drag of projectile shapes we see that the FN cilinder has the highest CD followed by the round balls, then the RN bullet and finally the ogived bullet untill we get to the really low drag Haack type ogives which exhibit the lowest CD values.

That means de facto that if all these shapes keep their posture of nose first in a dense target and all impact at the same velocity and impact energy, the FN would shed the most energy per unit distance penetrated and the Haack the least hence then that the FN would in fact have the shallowest penetration and the Haack the deepest penetration.

This off course does not happen. In fact just the ossposite happens in the target;

and the reason it does is the oblong projectile with an ogived nose shape will be subject to overturning in target with a massive increase in drag.

Now this is where I depart from the proponents of the FN in terms of their theories and observations.


By blunting the nose of a truncated cone into a flat meplat one is applying the concept of drag reduction, this is currently in practice used and validated in the RAAMICS program ! The US marines use bullets fired from standard caliber machine guns for this very purpose to defeat sea mines that threaten landing craft in shallow waters.

This is the only way one can in fact reduce drag of a oblong projectile in a dense medium. ( we are referring to projectiles that are passive cavitating projectiles such as bullets fired from guns)

By this action we achieve two things, the projectile remains stable and drag is reduced so that the projectile exhibits superior penetration........ but this then means by definition that less energy is shed per unit distance penetrated than the oblong ogived projectile that turns in the target.

So simply put if it penetreates deep and straight it has to be definition have less trauma per unit distance travelled than a RN bullet that turns and evokes huge drag and huge trauma during the turning process.

A factor directly employed by the British in their design of the MK 7 303 bullet after soft nosed and expanding bullets were banned for warfare.

But there is a caveat;

Because all the energy shed per unit distance penetrated does not necessarily translate to actual trauma the total wound volume of a deeper penetrating projectile may be greater than a shallow overturning projectile.