Date: 3:48 pm  Mon Nov 27, 1995        Number : 308 of 309
From: Thomas Simpson                   Base   : JFK_ASSN
To  : All                              Refer #: None
Subj: RE: RE: RE: RE: When was Gov Con Replies: None
Stat: Unsent                           Origin : 26 Nov 95  02:35:36


MSGID: 1:376/126 30b829bf

PID: WFIDO 1.10c
>Please provide specifics as to where the original documentation 
>of teh Army study can be found for reference and review.

     For the moment, I'll offer an article by Frank T. Chamberlin, Col, Medical
Corps, US Army (ret.), which can be found in _Handbook for Shooters and
Reloaders, Vol. II_, by P.O. Ackley, Plaza Publishing, 1966. Others can perhaps
be located in time.

> TS> others: the bullet entered Kennedys skull in the upper right-hand
> TS> "corner", as it were, 
> 
> TS> yawed violently, 
> 
>What, pray tell would cause such a high velocity bullet to YAW?

     The fact that high-velocity rifle bullets have a strong tendancy to yaw
upon entering soft tissue is widely known and documented. In fact a number of
militaries have taken advantage of the effect over the last century to partial
circuvent the international treaties governing the laws of war regarding the
use of softpoint ammunition, the first perhaps being the British, who fielded
the Mk. VII .303 round in 1908. This load used a bullet fitted with an
aluminum or fiber plug near the front that shifted the bullets center of
gravity towards the rear, redering it inherantly unstable and prone to yawing
almost instantly on impact, generating massive wound channels.

     The 162gr. FMJRN used in the 6.5 Mannlicher-Carcano is extraordinarily
long for its caliber and requires an unusualy tight twist ( about 1 in 9
inches) in order for it to be stabilised in flight. This causes the bullet to
be spun at considerably higher RPMs than most other bullets, something
approaching 150,000 rpm. This, combined with the bullets long overall length,
results in a bullet that often becomes unstable upon trasitioning from air to
tissue.

> TS> broke in two at the cannelure
>
>What would be hard enough to cause this Full Metal Jacketed bullet
>to break in two?

     Again, this is an effect that one runs into quite frequently. Some FMJ
bullets under some circumstances fragment upon impact with soft tissue. Some
fameous examples are certain steel jacketed 7.62mm NATO rounds loaded in Europe
and both the 55gr. M193  and 63gr. M855 5.56mm amunition used in the US M16A1
and M16A2 rifles, respectivly. The old M193 load, at certain ranges and under
certain circumstances, would often disintegrate into small fragments, but for
our discussion the performance of the newer M855 5.56mmm NATO load is more
interesing: it has a well documented history of yawing shortly after impact,
breaking in two at the cannelure and the fragmenting further. This is a bullet
that is extraordinarily long for its caliber and has a lighter-than-lead (in
this case, steel) insert at the tip, anmd is fired from a weapon that has a
much tighter than standard twist. As reference try looking up news accounts of
the Swiss government haveing to develop a new, "humane" version of this bullet
for their troops to use because of domestic political pressure.
  
> TS> All of this is consistant with the long performance
> TS> history of bullets of this type. 
> 
>A pretty broad and sweeping statement; got any detail data? 
> 
     I offer a piece of anecdotal evidence: 

     Back around the turn of the century, a very fameous profesional ivory
hunter and writer of books on African hunting, started experimenting with a
new, state of the art hunting rifle, the Mannlicher-Schoenauer, which used a
6.5mm cartrige and bullet that was pracicaly identical to that adopted by the
Italian military a few years earlier. Being used to much bigger bore rifles, he
was intrigued to find that it worked extremly well thin-skinned game, so he
decided to put the heavy recoiling big rifles away and try it on elephant, and
discoverd that, used with extreem care, one could often penetrate an elephants
skull and kill it instanly...except for the times that it didnt. Sometimes the
bullet would penetrate like an ice pick, others it would turn to dust and leave
you very close to a very angry elephant. Later he moved up to the slightly
bigger 7mm Mauser cartrige and found that it cured the problem.

     It simply goes to show you; inconsistancy is very consistant with the
record here.

>the energy must be stored in a vessel capable of elastic recoil, 
>much like air pressure is stored in an expanded balloon. 
>
>Would you care to do the math that proves the conversion of 
>energy between so many forms, ie.: bullet velocity, to peak &
>average pressure, to expansion of the vessel, followed by the
>contraction of the vessel, to the volume and velocity of the
>escaping fluid, converting that to Foot/Lbs of thrust, compared to 
>the remaining weight of the head, quantifying the accelleration
>produced, considering the opposing effect of the direct transfer 
>of momentum from the bullet to the head?  Piece of cake, huh?

     Well, gee, not being a physisist I cant give you all the formulas chapter
-and-verse, but consider this; grey matter is nothing like %100 water and
should be somewhat compressable. 

     Also, I'm not shure that compressability is the issue here. Try thinking
in terms of shock waves rebounding around inside the skull. That is a mecanisim
that can account for storing energy. After all, the speed of sound in water is
not infinite.


     more later...

-Tom

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