Fort Scott TUI Ammo For Hunting?

[Double Naught Spy]

grayfox, hydrostatic shock and hydraulic shock are terms that are defined, but not necessarily recognized by everyone as being distinct. I like this guy's definitions and this article is a pretty read...

https://www.ballisticstudies.com/Knowled...lling.html
Hydraulic shock is the civil engineers term also known as water hammer but in terminal ballistics context refers to the pressure of accelerated fluid particles that create the temporary wound channel.

Hydrostatic shock transfer refers to the effect when shock waves travel through flesh to distant nerve centers, disrupting their ability to emit electrical impulses.

From what FS is describing of nearby organs, it sounds like hydraulic shock, but that is being pedantic on my part, but hydraulic shock and temporary wound cavities happen with all penetrating projectiles from firearms (for this discussion), but not all produce hydrostatic shock that shuts down the nervous system from a wound located nowhere near the nervous system.

Michael Courtney (you can google his name for his articles) seems more inclined to mix the two meanings (as many do) from what I recall and did some pistol rounds testing on raccoons and claimed they were killed by hydrostatic shock, even via firing into the water next to a raccoon. That is very interesting and I don't know that he is wrong. However, you have a relatively low velocity projectile (as compared to rifles) producing a kill via a shock wave in the water that transferred to the animal. Note, this is a small animal.

This is a quote from the abstract or summary of a foreign dissertation that seems to explain the means of death via hydrostatic shock (to the brain centers)... https://is.muni.cz/th/132384/lf_d/annota...nglish.txt

https://is.muni.cz/th/132384/lf_d/ (original link)

Cufflike pattern haemorrhages around small brain vessels were found in all specimens. These haemorrhages are caused by sudden changes of the intravascular blood pressure as a result of a compression of intrathoracic great vessels by a shock wave caused by a penetrating bullet. At the end of work are outlined clinical problems of these types of injuries. It is highlighted in particular the potential impact on the early development of degenerative changes in the brain.

In other words, a sudden increase in blood pressure caused micro bleeds in the brain. My guess is that they occurred elsewhere too. Such as might happen when hit in the body with a baseball or punch to the chest. Obviously, the health of the victim comes into play with factors such as advanced age, smoking, and drinking that can all put people at risk for microbleeds even without sudden impacts.

So it seems to me that there are multiple factors at play. You must take the size/weight/volume of the target into account, shot placement, and the size, weight, velocity, energy at impact of the bullet. For example, a .223 55 gr. bullet impacting at 3050 fps may produce the desired effect in a goat, but not in an elephant. Courtney claims to get it at ~1000-1100 fps in a raccoon from a pistol round, but I would not expect he would get a comparable result on a 300 lb boar with similar shot placement.

Every time one of us shoots an animal in a non-CNS location, where the bullet does not pass close by CNS structures, yet the animal falls over dead, that is going to be hydrostatic shock. It does happen with Grendel rounds at various velocities. I think we have all seen it happen. We have all probably made a very similar shot on a similar size/weight animal and had it not die in place. That is where all this gets weird.

I have read and heard suggested that facts such as direction of bullet travel relative to the brain matters. So a quartering away shot should be more lethal than a quartering toward shot because quartering away, the impact energy sends a pulse in the brain's direction and quartering toward would send the pulse away from the brain. Also, whether or not the animal has a lungful of air matters. I have seen no information on this to suggest either one of these theories is valid or invalid. I really like the first theory because it is more testable than the second, at least with my abilities and opportunities.

I know a lot of folks that shoot "behind the ear" and that it kills every time. As I have noted several times, where you shoot behind the ear really can matter. Shooting behind the ear on a hog places the bullet behind the skull. In a head up position, behind the ear places the bullet above the spine. Sometimes they will drop dead and sometimes they will survive and heal up long enough to be killed months or years later, the hydraulic and hydrostatic forces failing to work their magic despite being very close to both the spine and the brain, the bullet simply having passed through muscle, fat, and skin.

Anyway, I am sure somebody could derive a formula to come up with when hydrostatic shock is more likely to result given various factors. However, the target's attributes are ever bit as critical as the projectiles attributes and it is not simply a matter of simple velocity or energy of the projectile to determine when hydrostatic shock may occur. There is always going to be shock waves, but there isn't always going to be hydrostatic shock.