I used to use the term hydrostatic shock until this past year when I learned in another forum in a discussion of the same topic that hydrostatic shock is a misnomer.
From Wiki, the definiton of hydrostatice...
Fluid statics (also called hydrostatics) is the science of fluids at rest, and is a sub-field within fluid mechanics. The term usually refers to the mathematical treatment of the subject. It embraces the study of the conditions under which fluids are at rest in stable equilibrium. The use of fluid to do work is called hydraulics, and the science of fluids in motion is fluid dynamics.
Note the last sentence regarding hydraulics.
Here is a definiton of static...
- of bodies, masses, or forces at rest or in equilibrium
- not moving or progressing; at rest; inactive; stationary
So the more correct term is hydraulic shock.
Now that we have that out of the way, let's look at the safe experiment. What's different about a safe and animal flesh? Elasticity or the lack of it. Materials that dont bend or flex wiil break more readily tham materials that are elastic or flexible. So the safe experiment does not apply to hunting. It does show that that liquid transmits pressure better than air because it does not compress.
Animal tissue is is elastic and it will stretch and return to it's former state if it's not stretched beyond it's elastic point. This aspect of terminal balisitics is know as temporary wound channel. Most "shock energy" transmitted through an animal's body is absorbed. If there is enough hydraulic shock to exceed the the elastictic limits of the tissue then it will not return to its former state and we have permanent wound channel. More fragile tissue such as lungs and liver would be more suspetible to permanant damage then lets say the heart, flesh, etc.
Here is where a bullets design is important. The shape and velocity of the bullet as it passes through an animal will detremine how much permanant damage is done. The more flat/square the frontal area is and the faster it is moving, the more it will deystroy tissue by exceeding the tissues elastic limits. This in turn cause hemoraging, which in turn causes low blood pressure, which in turn causes a lack of oxygen to the brain, which in turn causes death. the more flat/square surfaces of monmetal bullets and blunt hard cast bullets do more damage than rounded front mushroomed jacketed bullets which do more damage than spitzer shaped non-expanding bullets. The later doing very little damage at all unless it directly strikes a critcal organ such as the heart or spine, etc.
You will often hear or read arbitrary minimum KE numbers needed to kill a particular species of animal. These minimum energy numbers have nowhere near the required energy to deystroy organs or inject any letahal hydraulic shock to the animals system. What they better represent is the "momentum" the bullet has to penetrate the animal which is based on the bullet's velocity, mass and shape. The bullets shape as it impacts and passes through is dependant on its design and construction. The more flat and greater the frontal area, the more momentum it will need to penetrate and the more permenant damage it will do. The bullet will also loose some energy when it is deformened on impact which means it will loose some velocity/momentum.
In the final analysis, hydraulic shock *usually* does not do much signifacant damage to the animal other than the permenat wound channel created by the bullet, because of the elasticity of the animals tisssue that absorbs the hydraulic shock and returns to it form. The best strategy for killing animals quickly, other than destroying the CNS, is to put a hole through it where it will loose the most blood the quickest and the larger the better. Animals are not "shocked" to death. They die as a result of lack of oxygen to the brain period. In some rare cases it might be possible for hydraulic shock to cuase the heart to fail which in turn stops oxygen to the brain. But that's all complex and difficult to quantify.