The term hydrostatic
seems to be a term born of ignorance and the love of many for all the extra "syllabobbables" that they can tack onto a good word. The phenomenon that it refers-to (ignoring the alleged effect for the moment) is simple hydraulics, with the applied force and pressure being dynamic rather than static.
The basic physics principle that's involved is simple and well known — pressure applied to a liquid
(incompressible) is applied by that liquid, equally and undiminished, over its entire surface
. This principle is what operates hydraulic jacks, hydraulic lifts, all hydraulic cylinders — a hydraulic piston applies a force to a small surface of the fluid, and the pressure
(force per square inch) is applied equally and undiminished to all surfaces of the fluid.
That's why a can of water, struck by a fast bullet, becomes so quickly and dramatically a mangled twist of metal and a cloud of spray. The bullet is a rapidly moving hydraulic piston, and the water — incompressible — applies the pressure of the bullet's impact to all surfaces of the water (dynamically, not statically).
A heart shot can devastate the heart if it strikes a ventricle at the moment when it's turgid with blood
but be only slowly fatal by causing an empty ventricle to leak blood slowly from a bullet hole. In a similar but unrelated way, a pin ***** pops an inflated balloon but simply makes a leak hole in a flaccid balloon.
My uncle — an Army surgeon — told me of "superficial" but fatal wounds in soldiers' thighs that must've struck the femoral arteries during one precise instant when those arteries were turgid with pulses of blood. Apparently, the essentially instantaneous hydraulic transfer of the bullet's impact pressure devastated the heart as well as the artery and was thus immediately fatal. This was — is — by no means typical of bullet wounds in the thigh, obviously, including thigh wounds that penetrate the femoral artery.
No one can time or place a shot so as to be certain to get this instantaneously fatal effect, and the concept of "-static" is nonsense anyway. I use the term hydraulic shock
for the known phenomenon of basic physics, but I've never believed it to be the magically instantaneous killer that so many theorists have claimed for it. Observations and experience are usually better witnesses to actual real-world facts and phenomena than opinion and theory are.