Home Forums Hunting & Shooting Hunting Rifles Speed vs Energy?

Not shocked.

But 😂

According to some in the modern archery hunting fraternity, you can deliver hydrostatic shock via the humble speed of an arrow.

SLASH product brand marketing states:

"Hydrostatic shock or shock pressure occurs when an arrow’s kinetic energy is converted into a lethal, fluid pressure wave inside an animal
The more hydrostatic shock, the quicker the kill."

RIPPER product brand marketing states:

"The “Ripper” is different from other expandables in that the blades are totally recessed during flight and initial impact. The delayed opening
of the blades allows the broadhead to save kinetic energy and deliver the most hydrostatic shock when cutting through skin, flesh and bone".

I will call B S on this. blood pressure lost is what kills .no blood pressure is no oxygen to the vital organs = your dead don't matter what you are

I remember Dutch/Arnie in Predator saying; " If it bleeds we can kill it". ..

is braining elephants with solids less effective[slower killers] than same calibre expanding mono-metals
that can also adequately reach the brain?




The material bullet did the work and spent non-substance kinetic energy in the process.

( the bullet gained that energy because 'work' was done on it by a charge of propellant)

I think most of us can agree there's certainly a bit of BS going on here. However, anyone who's had a game animal drop in it's tracks should realize that lost blood pressure isn't the only thing that puts an animal down; they may not be dead instantly but they can obviously go down, which is where the shock discussions come into play. As I'm sure you and most others know it's damage to the nervous system that drops them in their tracks, regardless whether that damage is caused by bullet/bone impact or by another mechanism.

It sounds like you're calling BS on the "hydrostatic shock" thing, whereby a shockwave supposedly travels through arteries to the vital organs and shuts them down? I think that's hogwash as well. I do believe though that a shock wave traveling through the body (as it travels through any other medium, at varying speeds) can cause enough temporary damage to the nervous system (I'm guessing mostly the spine) to basically knock them out, akin to a punch in the jaw or back of the head. I also believe through experience that mechanism is unreliable and not to be counted on.

I'm pretty sure the spine doesn't get electrocuted through the rib cage though...

I'm one of those who think that the idea that a shock wave can be propagated along the arteries or veins to the brain from a distance away is BS. It seems to me from a hydraulic point of view that a bullet which severs an artery, far from causing an overpressure along the line, actually has the opposite effect, as the medium - blood - exits the system. If the artery's big enough, and the damage great, the sudden drop in blood pressure may cause rapid unconsciousness, but that isn't "hydrostatic shock"

As far as the "shock wave" affecting the spine, IME you can have cases where this occurs, but the bullet has to be very close to the spinal column - close enough to do actual damage to it, even if the spinal cord itself is not directly hit. A bullet which hits the bony processes above the spine can put an animal on the ground, for example, though it may soon recover and get up again. Another thing that can occur is that the bullet damages a nerve junction which is connected to the spinal cord, such as the axillary plexus, and that in turn does enough damage to put the animal down on the spot. As well, there are those arteries and veins which run close to the spine which, if perforated, will see the animal off even if the spine itself is not hit. I myself rather favour a shot aimed to hit the shoulderblade on deer from side on(where available), aiming to damage as many of these as I can - axillary plexus, spinal cord, arteries - both by the direct action of the bullet and by secondary projectiles (bone fragments). It has resulted in quite a number of animals DRT.

enough science all`s i can say is if you shoot a deer thru the lung area with my handload that shoots 3800fps out of a 100 grain bullet i will turn that deer`s insides to red icky jelly even at 200 yards and that deer won`t be walkin away . and my 30-06 with a 165 grain bullet shootin around 2800 fps won`t do that ever and i will have to blood trail that dang deer again.

Let’s start with the fact that your understanding of physics is not very good and your ‘facts’ above regarding energy transfer are completely wrong.

Let’s do the math correctly:

5,996.8 ft-lbs = 300g @ 3000 fps (impact)
4,164.4 ft-lbs = 300g @ 2500 fps (exit)
==========================
1,8324.4 ft-lbs = Energy transferred (NOT 500 ft-lbs as you stated)

1998.9 ft-lbs = 100g @ 3000 fps (your 257 WBY example)

There are too many variables regarding differences in bullet construction, initial diameter, final diameter, expansion rate, initial weight, weight retained and other factors to make very meaningful predictions regarding what each bullet will do in any particular case. That said, tissue destruction requires work, which requires energy transfer. No energy transfer, no tissue destruction.

All you can say with authority is the .257 WBY load, which transfers ALL its energy to the animal has the potential to do more destruction than the 300g bullet that transfers less energy.




You make my argument for me – two bullets with the same velocity, one which deforms and transfers significant energy to the target and one which does not. Since the impact velocity is the same it is clearly not the only factor. It is the energy transferred that determines how much destruction is possible or done. The more energy transferred, the greater the destruction.



Exactly. Speed is not irrelevant, as it partially determines energy. But it is not the only determinant and has far less to do with how available energy is transferred than does bullet construction.



You just argued above that, if speed was the determinant, two very different bullets at the same speed would make comparable wound channels but “It Doesn’t”. Now you want to argue the opposite?



Berger claims their bullets “dump their energy where it is most effective, inside the animal.” This from their “Lines and Designs” page regarding their hunting bullets. https://bergerbullets.com/information/line-and-designs/

No mention of “speed”…

The only mention of “velocity” on that page is “impact velocity and animal size will effect expansion results” with regard to their varmint bullets. Expansion characteristics have an obvious impact on energy transfer, as you point out when you discuss FMJ and ELD-M bullets and again when you point out in your statement above: “…the full metal jacket bullets that deposit the least amount of energy in an animal are the slowest killing bullets”. Once again you are arguing that speed is not the primary determinant .

You flip-flop so many times a guy would get dizzy trying to follow your changing logic.

Shoots 3800 fps out of a 100-grain bullet? What kind of rifle are you shootin' out of that bullet?

+1

I'd agree with all this.

LOL, that's ironic



Impact speed and bullet construction both play a large combined role in how much energy gets used to destroy and displace tissue. The bullet has to impact within the velocity window for which it is designed to operate for it to maximize the energy that gets used for tissue destruction. And again, it's not just about energy transfer, it's about the energy that gets used to destroy tissue. A FMJ can transfer all its energy by penetrating length-wise from stem to stern and leaving a wound with the cross-section of a pencil, and a bullet of similar mass and velocity can transfer all its energy by creating a balloon of destruction on a broadside shot that doesn't exit the far side of the rib cage. The difference is that one bullet uses its energy to part tissue as it passes by (creating mainly a temporary wound cavity), and the other bullet uses its energy to destroy tissue (permanent wound cavity). Both will kill, but the time it takes on average for the animal to die from such shot placement favours the greater destruction of vital organ tissue.

On a side note, obviously killing power has more to do with destroying the "right" tissue in the right location than just the sheer magnitude of tissue destroyed. A long, narrow wound channel in the wrong location is not going to kill as quickly as a wide, shallow wound in the right place, and visa versa.

Shoot-em in the head and they are Roy dead! 😎

so be it muzzle loader or ultramag, you will always get hydraulic shock effect?

you do realise that hydraulic shock [or 'water hammer' effect] applies to excess line pressure situations with non-compressible fluids?

Shot creatures are not like (water or hydraulic oil) rigid pipe closed systems,

Arteries are elastic/can expand, [abillity to distend and increase volume with pressure increases]
Blood has a compressible fluid {gas} component.

Jordan -

I agree 100% that placement counts.

A .22LR that expends all its energy in a hoof isn't likely to be an immediate or direct cause of death (death by infection at a later date maybe). By contrast, a .22LR behind the ear can dispatch fairly large animals rather quickly.

Both bullets have the same initial nominal velocity, mass, and energy. One fails to disrupt vital function due to placement, but both initially have identical potential. If speed was the determining factor, both would kill equally well. My discussion in the posts above assume good placement when i talk about energy transfer and the resulting disruption of vital function (or lack thereof).

Placement matters, but so does bullet construction, as you point out. I tried using FMJs on coyotes but they were slow killers and I wasn't interested in the hides or torturing the coyotes - went back to cup-and core soft points and tipped, same velocity but much better. (To, I assume, no one's surprise.)

Fixt Beav !

Non +P velocity 115 Partitions launched from a 257 Roberts involving vitals and front leg bone or shoulder joint have been the best DRT load for me.

The good news is that most experienced hunters have selected a weapon-package that will be lethal to the targeted-game-animal as long as we make good shot placement and stay within reasonable parameters for that selected cartridge.

(We use different rules for the 30-30 versus the 375hh, but both are very deadly within their confines)

Glad I don't have to calculate much as long as I stay within those rules!!

I really cannot find a logical reason for why, but the comparatively lower speed/lower energy Roberts with the 115 Partition just turns lights out. It get's full penetration on our smaller coastal deer even when it breaks bone. I typically hunt in fading light after sunset when there is very little remaining light. I hunt in areas where the vegetation can me miserably thick. The temps are normally warm. A deer that runs and goes unrecovered will be waste by morning. For that reason I like to anchor them even if it does trash a lot of shoulder meat. In this shot I was elevated in a stand about 20 feet off the ground and this deer was about 80 yards away. I was shooting to break the offside shoulder/leg. But I am not perfect at guessing just where the joint is going to be on the off side. In this case I didn't get it, but this deer never budged after it was hit. For a woods rifle I will never have any need for anything other than the 77 UL chambered in the mild Roberts pushing Partitions at a rather pedestrian pace.

how do you upload a photo

That 115-grain Partition is a winner no matter the velocity. I don't know what fps you are getting in your Ruger 77 UL with 20" bbl, but in my twin 77s with 22" bbls I get 2845 - 2860 fps (oh, forgot new batch of H4350 - 2875 fps). 43-44 grains H4350. I noted a load from John Barsness some time ago 45 grains H4350 2900 fps plus don't remember what his barrel length was.

I have hit Whitetail and Mule deer shoulders and ribs with that bullet at ranges from 25 yards to 300 yards and result is all the same....dead animal.

The largest White tail I have shot dressed out at 270 lbs. The lasered distance was 280 yards and took out both shoulders. I posted it indicating the 115 grain was the culprit and I got a compliment from Big Stick (Boxer), but looking back not sure it was the deer or the cartridge or the bullet he was referring to. Wished I would have saved that post.



Velocity, bullet construction, bullet placement.