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Question by dbell. Uploaded on January 22, 2011
it is the force the bullet makes on impact to the the target
it's the kinectic energy of the bullet - or how hard it hits you - it is based on both the velocity and the weight of the bullet - so a lighter bullet traveling very quick can have the same kinetic energy as a heavier bullet traveling slower - it is an important but not the only factor in determining what damage the bullet will do when it hits.
I took the following explanation from http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUNBLST.html
The external ballistics of a bullet's path can be determined by several formulae, the simplest of which is:
Kinetic Energy (KE) = 1/2 MV2
Velocity (V) is usually given in feet/second (fps) and mass (M) is given in pounds, derived from the weight (W) of the bullet in grains, divided by 7000 grains per pound times the acceleration of gravity (32 ft/sec) so that:
Kinetic Energy (KE) = W(V)2 / (450,435) ft/lb
This is the bullet's energy as it leaves the muzzle, but the ballistic coefficient (BC) will determine the amount of KE delivered to the target as air resistance is encountered.
As my physics teacher says, "Obey the laws of physics, everything else is optional."
that was a good question j4huntfish, i knew what it ment but wasnt quite sure how it work out in mathmatical terms, sounds like the same way to find the ke for archer. thanks gentlemen
It's kinda like a Woman standing on your foot with high keel shoes. Her slap may not effect you much, but her husband with those size 17 1/2 EEEEEEEE size boots will!
foot pounds of energy is kinetic energy, minus wound channel and hydrostatic shock.
hahaha clay now that was funny!!!!
Good one crusty.
Clay, where do you come up with this stuff? Sounds like the voice of experience!
It also depends on the bullet, which Clay kind of brought up.
A 5.56x45mm NATO ball round traveling at 3000 fps, at 62 grains, will have over 1200 ft/lbs. of kinetic energy.
A .45 ACP Hydrashock traveling at 850 fps, at 230 grains, will have just over 360 ft/lbs. of kinetic energy.
Logic would suggest that a 5.56x45mm NATO ball round would carry more kinetic energy, and the math shows this to be theoretically true. But you put that small of a round through someone, and the bullet isn't meant to expand, then you blow a VERY small wound channel through that individual.
Now, .45 ACP Hydrashock traveling less than a third of the velocity, but weighing 3.7 times as much and twice the diameter, will create a much bigger wound channel, because it is designed to do just that. It will also dump more kinetic energy out into the target, creating a bigger effect, such as that hydrostatic shock that Clay brought up. This "dump" of kinetic energy into the target can create a shockwave through the target, incapacitating it rather effectively.
This principle of hydrostatic shock or hydraulic shock also applies to double taps. Multiple shock waves of bullets hitting soft tissue create a incapacitating effect, which is why LE agents, and military are trained to fire two shots center mass.
There is a science behind killing people, although it is a shame that we even have to study this at all in the military or LE community.
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