Originally Posted by muscogee
You have made an inductive argument based on anecdotal evidence and no data. I assume you're familiar with David Hume's argument about inductive reasoning. Is it possible that the 9mm is as effective than the .40S&W or 357SIG? Is there a point where additional velocity, diameter, weight produce no appreciable gain in stopping an attack? Notice that very few people use a 44 Magnum for personal defense.
The data I've seen is too flawed to draw a reliable conclusion. It fails to consider too many variables. For example, it fails to consider distance. Were the shots taken at arm's length, 10 feet, 25 feet, 50 feet, or longer? Is a 380 as effective at arm's length as a 9mm at 25 feet? The data also leaves out shot placement. Is a 380 to the heart at arm's length as effective as a 9mm to the heart at the same range? Does that effectiveness decrease with range? Without considering these factors, a good guess isn't possible so we're back to personal opinion.
The hydrodynamic pressure idea was popular years ago, but the latest I've seen indicates that the stretch cavity it forms has little effect on stopping an attack. The stretch cavity simply snaps back after the bullet passes.
I'm not familiar with Courtney. Do you have a link?
David Hume's argument about inductive reasoning is related to the unknowability of nature. That is, although, in all our experience, A follows B, we cannot be sure that A will always follow B in the future. He points out that this is not saying that there can be a effect without an cause. We can see that this formulation implies that the causal connection or mechanism between A and B is unknown and that we are considering no more than a relationship in time between A and B.
Another way of putting this is that inductive reasoning links what we know and observe of the behavior of objects in the past persists in the behavior of those objects in the future and in the unobserved present. As we cannot be certain that nature will remain the same in the future as it has in the past, such reasoning must be open to doubt.
As such it might well be said that I am making a multifaceted
inductive argument about the behavior of different loadings of different cartridges. The argument against that view is that I am relying on an underlying explanation about how bullets damage tissue. If we ignore that explanation or theory for now then the remaining multifaceted argument shows that several different aspect of the observed behavior of bullet wounding all point in the same direction relative to the expected effects of the .380 relative to other cartridges.
The difference between science and philosophy is that science looks for the underlying principles that provide causal links between apparently causal behavior observed as a relationship in time. When dealing with those principles discovered by scientific process we move into a different realm of understanding. That is, we must always be aware that any given principle is false, but our uncertainty otherwise about the consistency of nature is very much reduced. Although there might be parts of the universe where some particular principle is false though it is true here, we can have a very high certainty that it will remain true in this region of the universe.
So, relative to the ability of a bullet wound to act towards preventing further aggressive activity I am claiming that
A) Simple physics tells us how moving solids interact with fluids.
B) Wounding effects are produced by the dynamic pressure wave of (A).
C) Those wounding effects can be enumerated and explained in terms of dynamic pressure waves in a way that relates the kinetic energy and the speed and mass of the bullet to the nature and severity of the wounds produced.
D) Greater wounding effects can be expected to have a greater contribution towards the prevention of further aggressive activity.
It is clear that the variability of individuals in terms of fitness size, thickness of fat and muscle layers at least will produce considerable variation with respect to the end result of a bullet fired along a particular track. Further to that, in the real world the variations of the wound track, the variations of clothing, cartridge loading and bullet design will produce much extra variability. The practice of continuing to shoot until the assailant is clearly unable to continue the fight will introduce still more variability since the last few shot can be fired when the assailant is actually incapacitated but that this is no sufficiently obvious to the defender. The combination of these factors will make it extremely difficult to extract meaningful data from real world shooting events.
With regard to (A) we can say that any solid moving through a fluid medium must create a dynamic pressure wave which is approximately proportional to its frontal area and the square of its speed. In other words, if we, for example halve the speed and quadruple the frontal area, the pressure wave configuration remains much the same. Quite simple, the moving body or projectile has to do work against the fluid to move it out of its path. In doing so there is a necessary transfer of energy from projectile to fluid produced by the product of the retarding force on the front of the projectile and the distance it moves per brief interval.
This retarding force is the sum of the pressures across the front of the projectile in the direction of its movement. It is worth noting that for a streamlined or semi streamlined shape, such as a spire point or round nose bullet, much of the pressure is at an angle to the direction of movement and so only a component of those various pressures provides a retarding force. As a result, such bullets transfer their energy more slowly and so produce a less intense pressure wave than flat fronted bullets.
This pressure wave is a matter of simple physics and not uninformed conjecture. It is strongest in the middle of the front of the bullet but as we are dealing with hydrodynamic pressure it will decrease with distance from the source as it pushes the fluid medium ahead and to the sides. We can think of the main part of the pressure field as isopressure surfaces rather like as series of partial spherical surfaces extending and widening in front of the bullet as their pressure becomes less.
It is easy to see the effect of this on cellular tissue. Along directions perpendicular to the isopressure surfaces cells are compressed and flattened. As cell membranes have limited elasticity, those that exceed their elasticity burst. This happens, in general, before the bullet makes contact with them. Only in the earliest depth after impact before the pressure has grown does the bullet contact intact cells. As this dynamic pressure forces tissue to the side of track it is stretched along circles about the axis of the bullet track. A little simple mathematics shows that the stretching is greatest closest to the bullet track and decreases with increasing distance from it.
Depending on the pressures this results in pureed cells in front of and to some distance to the side of track when the bullet has enough speed so that the permanent cavity is slightly or considerably greater than expanded bullet diameter. Only when the speed falls low enough will the bullet again contact whole cells and will then stretch and tear tissue as it passes through. This section of track will have a diameter less than expanded bullet diameter.
Immediately outside the pureed zone the stretching will be enough to produce approximately radial tears. Beyond that it will produce damage to capilliaries and small nerves which will be seen as bloodshot flesh. Beyond that there will be temporary damage to small nerves which will result in temporary paralysis or numbing. There is a frequently repeated claim that tissue is elastic but in fact its elasticity varies and also varies with rapidity of stretching. The connective tissue along the direction of a muscle is necessarily non stretchy because otherwise it would waste energy. Across the muscle the connective tissue is weak because that is not the direction in which it applies load. Nerve and blood vessel have enough stretch to withstand normal activities, but, as many of us know from experience, a punch on the arm can make it unusable to some extent for more than a few seconds. A sufficiently powerful bullet passing close to the heart but not structurally damaging it could stop it functioning for long enough to end the fight or kill the individual before associated blood loss could do so.
What we can see from this is that the zones of damage around a bullet track, apart from it last two or three inches, result in permanent loss of function, loss of function which will heal to recover only partial function, loss of function which will heal completely and temporary loss of function. All of this will reduce the ability to fight as damage is done to skeletal muscles, vital organs and blood pressure.
We can also see that outside the pureed zone large blood vessels will be squashed and stretched but often not ruptured. This will inevitably produce a high pressure pulse of blood through those vessels into zones which have not been squashed. The larger the blood vessel the less the pulse will be dissipated and so blood vessels to the heart and brain will carry significant energy. From consistent findings of bleding in, if I remember correctly, the medulla oblongata of suicide victims who had shot themselves in the chest it seems that this is the mechanism behind the Courtneys' findings on rapid collapse.
It is obvious that even with a bullet of sufficient speed and optimum penetration its position relative to blood vessels which will achieve this effect is effectively random so that small differences in placement can have a big difference in outcome. Also clear from the Courtneys' work is that more powerful pressure waves reduce the randomness of the outcome.
If you are firing an appropriate cartridge you will have some probability of such a rapid collapse. Without that good fortune, your effectiveness will go up in much the same way that the probability of rapid collapse goes up. The larger the zone of damage the greater the fighting ability or the attacker is likely to be degraded. With each hit that ability is further degraded, provided you are not good enough to shoot through the same hole. Each hit will cause physical and mental disturbance which will delay the next controlled shot. The one who produces enough degradation fastest will be the winner.
It has long been said by famous authorities that death from gunshot wounds comes in only from two causes - blood pressure loss and a direct hit to the brain or upper spine. For the purpose of self defense that is irrelevant. Death might be a desirable result but our principle concern is not being shot before the attacker is incapacitated. That can be achieved with a shot to the brain or upper spine but that is too difficult a target to be a good strategy. It can also be achieved by remote damage to the brain as demonstrated by the Courtneys' work on deer, but that is not certain. What is left is the physical and mental disturbance caused by good powerful hits slowing the opponent's rate of controlled fire to the extent, if possible and fortunate, that you can make the next hit before he can recover control. In that respect bear in mind also that with part of his musculature out of action his body will not work as his mind anticipates and so that too will delay his return to aim.
All of this, short of a brain or spine shot, depends either on a bullet producing a wide temporary cavity and moderate or optimum penetration or that power being compensated for by multiple bullets in the same time interval. Since the time to the first shot is very little influenced by the cartridge fired, the less powerful rounds suffer an immediate disadvantage. After that the more powerful rounds will usually have longer delays between shots but that difference is much less than the difference in damage produced.
None of this is reason not to use a .380, but it is reason not to use one unless you have no other reasonable choice. If you have that choice, part of which is the ability to shoot it competently, then shoot a 357SIG, hot 10mm or hot 45ACP.
To answer specific questions, there is probably little difference between a shot to the heart at close range from a .380 relative to a 9mm unless the individual is very fat or has on very obstructive clothing.
From the arguments above a .40S&W or 357SIG is always more effective, on average, than a 9mm. Relative to the Courtney effect there is little point going above the hot 10mms and and .45ACP, but they both do better than the 357SIG.
The .44 Magnum with light fast self defense bullets will better the 10 and 45 but the gains become marginal. Most loads for the .44 Magnum are intended for hunting and are engineered for greater penetration than is optimum for self defense and so are unsuitable for this purpose. When the weight and bulk of the pistol are brought into the equation, I think the .44 Magnum is not a serious contender.
A 90 or 100gn .380 bullet at arms length will be as effective as a 9mm of the same weight at the distance when its speed has fallen to the same level. Ballistic tables will tell you when that is, but it is a long way.
It is unfortunate that there is not and is unlikely to be data that will substantiate all these issues, but I think the arguments above are a long way from simple opinion. They are science based and are open to counter argument and examples.
By the way, the hydrodynamic idea of some decades ago was called hydrostatic shock. Just the fact that the originators did not understand enough to know the difference between hydrodynamic and hydrostatic effect is enough to make you doubt its validity. The fact that it came, as far as I know, with no further explanation but the mystery of its scientific sounding name should really finish it off. It should not be confused with my explanation of hydrodynamics or ballistic pressure wave or with the Courtneys' work.
Incidentally the Courtneys did not set out to show how the rapid collapse came about but simply to compare its probability to the peak pressure of the ballistic pressure wave. Since such rapid collapse can come into effect only via the brain, the only reasonable explanations are some effect coming from nerve damage or an effect on the brain via a pressure pulse. Later work in the Czech Republic makes it very likely that the pressure pulse is the mechanism, but we have to remember that relatively light slaps and punches to areas away from the head can produce rapid collapse.
Sincere thanks to uz2bUSMC for the Courtney references.