I have finally reposted my terminal ballistics website to a new host server at:

http://www.mindspring.com/~ulfhere/ballistics/wounding.html

It has been completely re-edited and revised and has a few new figures.

Thanks Harald,

Unlike my friend (who is smarter than I) and who printed it out I have missed that site a lot.

To quote this friend from memory about what he wrote about Haralds site. "He clearly understands this as well as anyone and has put it on paper better than anyone that I know of".

Folks if you have not looked at this ite you are missing good work.

Harald you are to be commended.

.
Harold - Thanks for the effort to keep the site up.

And about time too.... LOL! I was getting serious withdrawal symptoms.

Thanks for maintaining the site, Harald. Dutch.

HARALD,
Thank you. I need all the help I can get.

Harald,

Interesting site thanks for putting it back into circulation.

I have a question though. How much influence on the mythical "knock down" does the bullet's frontal shape and trailing edges have?
EDIT-
From reading your website data it is obviuous that you have put forth considerable effort and knowledge in comprehending the terminal performance of the bullet. What I am asking is what effect does the bullet's geometry have on the "knock down" factor. For example I have shot somewhere in the neighborhood of 200 whitetail deer with a Foster or Brenneke style 12 gauge slug. Almost without exception if the deer was hit in well and within 50 yards he went right down. I have shot in the neighborhood of 40 deer with a 12 gauge sabot. The deer shot with the sabot almost without exception ran off without going down. The ranges and hit locations are for all practical purposes the same for both projectiles. The muzzle engergies are similar for both projectiles. Both projectiles are technically deforming i.e. soft points. The biggest single difference between the two projectiles is diameter, with the Foster/Brenneke slug measuring 0.729" and the sabot 0.45" approximately. The sabots do completely penetrate the animal while the Foster/Brenneke slugs do not.

Could there be a hydrodynamic infulence here? I am refering to the column of tissue and animal bodily fliuds which dissipate the projectiles energy. More specifically do yoy think that this "column", if it exists, contributes an additional mass to the momentum equation, which in turns provides an additional "push" to the animal. This could explain the better "knock down" with the Foster/Brenneke slug.

Todd E

[ 06-01-2002, 20:19: Message edited by: Todd E ]

guess i will have to sell my .243!!

I read Harald as saying that unless the nervous system is hit that the animal will sucumb to the loss of blood pressure.

Also I believe I read that there is no "shock" effect.

I suppose that a .729 Slug makes a bigger hole than a .45 slug and the blood pressure drop is faster.

Don,
Do you really think so? I do not know if I believe that. I shot the aorta off of a bull moose and he didn't go right down and done the same to a few deer also, only one of the deer went right down. I have seen a few other deer take aorta hits and not drop. Given, they don't seem to run as far as a lung shot deer though. I cannot imagine a quicker way to drop the blood pressure than that.

I can't argue with a central nervous system hit though, that will definitely drop 'um in their tracks.

My point is not to argue. I am only asking an expert for his opinion. As I said Harald has obviously done his homework.

Harald,

If you are reading this I do have a few more questions. It appeared that some of your posted results were taken from referenced materials. Is that the case?

If data was posted from references, how do the test conditions compare between the various references and your tests, i.e. correlation study if you will?

What test media were the projectiles fired into and from what range(s)?

Would it be fair to say that a 45-70 shooting a 400 grain soft point at 2000 fps is an equal performer to a 458 Win Mag shooting a 500 grain soft point at 2100 fps?

Thanks,
Todd E

[ 06-04-2002, 03:53: Message edited by: Todd E ]

Yes I believe it but there is an exception I think. Somehow I recall reading that it depends upon which side of the heart is damaged ie the intake or pressure side.

I wonder out loud about a knock out punch? We have all seen it in boxing and even with a body punch the wind is knocked out.

So what if a very large bullet hits a small animal with great energy. Why won't it "knock" the animal out? Then of course it will succumb to blood pressure drop at the same time.

harold great site, it really helps to put alot of homework into the bullet selections and caliber choices for the game you hunt

All,

Thanks for the compliments. I'm pleased that you all enjoy the site.

Todd E,

Sorry to get back to you so late, I have been away for a few days. I think Don is on the right track. My first surmise would be that the soft lead slugs make a substantially larger wound than the sabot projectiles (copper or hard lead?). In any case I don't think "knock down", if it exists, has much to do with killing. Momentum transfer is trivial. At worst it could barely knock down an animal that was caught off guard. It certainly isn't enough to hurt it. It might put an animal out of action long enough for mortal traumas to take over. Its the penetration that does all the meaningful harm. Momentary paralysis is a different matter altogether, but that too is not harmful.

One thing you have to remember is that even with instantaneous cardiac arrest there is enough oxygen in the blood to stay on your feet for 5 to 10 seconds, maybe longer. An animal can run a fair distance in that time. I know something of ballistic injuries and try to consult medical authorities on the subject, but I know penetration mechanics a lot better than I know wound trauma.

The test results are almost all taken from wetpacks of newsprint or phonebooks. There is certainly some scatter in the data, but I have been impressed with its consistency (compare Finn Aagaard's calibration tests of the Remington .30-06 180 gr Core-Lokt to mine). Impact ranges were generally not reported. My tests are conducted at close ranges (10 feet or so).

As far as your comparison of .458 loads, I would hesitate to make a generalization, especially not knowing what bullets were involved. But beyond that I would pose a broader question. What would constitute "equal" performance for you? I doubt if the 400 gr would penetrate as far, so it would not equal the heavier load for buffalo hunting perhaps. However, on a smaller (but still very large) animal it may be better for your purposes.

Fats,

Please take my rantings on the .243 Win with a healthy dose of salt. The second instance has extenuating circumstances. That doe walked out right in front of me at 20 yards or so and knew she was busted. She was terrified and we stood looking at each other for several seconds. I tried not to make it obvious that I had seen her, but she saw me alright. When she didn't run I decided to shoot her per my mandate from the landowner to kill as many I found (he had 50 doe tags and the promise of another 50 from the warden). I deliberately shot her in the heart, which is not the quickest killing wound and she was already running on endorphines. So, its somewhat unfair to criticize the cartridge for not felling her. Then, there was the rain. I needed a dog badly in that stuff. I'm sure that both of those does piled up within a few seconds. My frustration was that they high tailed it into a mess and I couldn't track them without a blood trail. A little beagle would have walked right to them.

Is there "Knock Down Power" or not?

A 750 grain bullet going at 2700 f/s will have a much MOMENTUM and with a bullet diameter of 14,7 mm(577 TYRANNOSAUR) then i think that it will stop and knock over animals up to 200 kg. What do you think Harald and Todd E...?

I will try to handle the question from overkill as I got a B in Physics. Harald can always correct me.

The "knock down" can't be any more than the recoil of the gun can it?

I hope this answers your question.

Don, hypothetically it could be more, depending on how fast the momentum was changed. Force is the time rate of change of momentum. However, the distance over which a bullet loses velocity by penetration is very similar to the distance over which it accelerates down the bore of the rifle (and remember its not going as fast either), so the recoil of the weapon is a very good approximation of the "knock down" force delivered by the bullet. Now, I have no wish to subject myself to the abuse of the Tyrannosaur, et. al., but they are not in the killing category of recoil, even so.

The real issue in my mind, Overkill, is this: So what if the bullet could knock something down? People play football and get knocked all over the place and suffer no hurt. Getting knocked down is not much of an effect. Having a 3 to 5 cm hole explosively drilled through your vital organs is a likely to get your attention a lot faster. I think the knockdown effect is wrongfully attributed to the force of impact (which is small) when it ought properly be attributed to the trauma inflicted by heavy bore weapons.

Harald,

I take issue with only one aspect of the information you present in your "Terminal Ballistics" website. Although your technical critique of the performance indices is accurate, I believe that you unfairly assumed that Taylor et al were presenting their indices as scientific formulas precisely describing or predicting performance. As a scientist to assume that you were seeing scientific analysis when you saw formulas is an understandable assumption, but these men are not scientists rather they are vastly experienced hunters. I think that their actual intent was to provide a pragmatic means to transfer the observations of their vast experience to those of us who can never hope to equal their field experience. Discounting experience of this level as "myths" is unfair.

Fireplug

But Harald...!

If a dangerous animal is attacking you at short range(20 yards) then you have to stop him. If you shoot a 4" hole he is still running at you. And if the MOMENTUM of the bullet dont stop him then he is going to run over you. And it is because that i think the old hunters in africa always had a big double rifle in calibers like caliber .500-.577-.600 to stop the animal fast not to kill the animal fast.

I am going to do a little test in this weekend. I am going to put up a barrel with 200 litreof water inside. I put this barrel on a table 1 m high from the ground and then I shoot it with my .460 Weatherby with Hornady 500 grain soft nose bullet at 2600 f/s. Then I am going to see if the bullet KNOCK DOWN the barrel fast or not.

Fireplug,

My view of the TKO is two-fold:

1) It remains to be demonstrated that Taylor's claim is valid, let alone that his calculation of how the claim applies to any load is valid. That is not an unfair criticism. Whether his approach is "scientific" or not, every premise put forth by man is subject to question by others. There are a number of experienced hunters who can offer a contrary argument to the knockout theory. I don't pretend to know the answer.

2) The TKO is incorrectly (by Taylor's own assertion) applied to killing effect.

So, in my view, the TKO may be a myth (though I think there is something to the idea, if not much), but undeniably it is a "miscalculation" as regards its use generally for hunting loads, since none of us is hunting elephants for the most part and trying to stun them with brain shots.

I am trying to be fair and I have considerable respect for the genuine understanding of the most experienced hunters. But any time someone starts multiplying physical quantities together they presume to apply scientific means to a problem.

Let me put it another way. Will you buy your medicines from the guy working as an orderly or from a pharmacist? He's seen lots of sick people and he may even have a solid grasp of what is wrong, but that doesn't qualify him to mix chemicals and offer the concoction as a remedy for what ails you. Medicines that cure need to be based on scientific knowledge, then independently tested against a placebo, prescribed by a physician who can tell you that definitely you want this one and not that combination, and finally prepared by a pharmacist. There are a lot of unproved, unregulated "medicines" on the US market that go by the name of "herbal supplements" (so that they are outside the control of the Food and Drug Administration on both counts). I very much doubt that eating shark cartilege will prevent you from getting cancer, even if it is true that sharks apparently never get it.

Everyone is entitled to develop a theory, but then we all get a crack at disputing it. If its not founded on known physical principles then we immediately must be suspicious. And where is the supporting evidence or argument? We should be permitted to examine that and weigh it against our own experience and the experience of others. We should test the theory. Call it science or something else, but this is the approach that critical thinkers apply to any information they receive; whether from politicians, the TV news report, or the commercial advertisement.

Overkill,

If you really want to make this test meaningful, suspend the drum filled with 200 l of water from a swing of two ropes. Have a friend release this drum at its full height (3 or 4 m) so that it swings down at you. Fire your rifle at the drum as it reaches the bottom of the pendulum swing and see if it "stops" the drum as it is coming at you like a charging beastie. Important safety note: Make sure you are outside the radius of the upswing!

Overkill,

Don't use a table that's any good. The force of the impact will break the table top.

I shoot a lot of paper cartons filled with water as a bullet test. I broke a bench. Now I put them on the ground.