Bullet lethality: energy and velocity

[MTbackwoods]

I see a lot of articles and discussions on velocity vs energy. One is more important than the other, neither tells you anything, we're all idiots for pushing the envelope, blah blah blah. However, most people do not do an apples to apples comparison. One will site a .243 with a 100 grain soft point bullet vs a dangerous game rifle with a 400 grain solid. Others compare strictly calibers but not similar or even the same bullet. So what I would like to hear about is what kind of effects are people seeing on game shot right at the envelope. Meaning at or below the "recommended" energy threshold. All things being equal of course as far as velocity is concerned. Berger recommends 1,800 FPS and Hornady recommends 1,600 FPS. However, my 7mm obviously has different thresholds for the 2 ELD M's I load for it. The 180 hits 1,600 FPS and 1,034 ft/lbs at 1,500 yards and the 162 at 1,350 yards has similar velocity but 932 ft/lbs. So my question is this; at what point does velocity become moot and we have to set our limits based on energy?

 

[ATH]

Energy doesn't matter if your velocity falls below the expansion envelope of your bullet and it pencils through, unable to translate the energy into tissue damage. As an example I'm building my first 300 Blackout primarily as a home defense gun but in looking at things it's clear a lot of people are using bullets which simply will not consistently expand on flesh as they were designed for higher velocities. Other rounds can fall victim to this in both directions -- not expanding enough or expanding too violently. The energy has to translate into effective tissue damage. So both velocity and energy are important as they interact with bullet design.

 

[LaHunter]

Kinetic Energy=1/2Mass X Velocity squared. So velocity is the most significant contributor to the energy of a given bullet.

 

[MTbackwoods]

I understand the basics of velocity and energy on target. I know that velocity is necessary to cause expansion and energy is the bullets ability to displace fluids and create hydrostatic or hydraulic shock. I know the basic principles. I know this question isn't coming across quite right so I'll keep trying to word it until I can get it across correctly. As long as the bullet being used is impacting at or above the recommended velocity, at what point does the energy, or lack there of, become more important than the velocity itself? So let's pretend that the bullet is always going to expand reliably, what amount of energy is going to prove to be lethal on elk, deer, etc. For example, let's say I shoot a bull elk at 1,000 yards behind the shoulder and he drops dead in his tracks and the bullet had 1,300 ft/lbs of energy. Now let's say in a different world that same bull is at 1,100 yards and I put the same bullet in the same spot yet he walks away because the bullet only had 1,150 ft/lbs of energy. So 1,300 ft/lbs would be the threshold for ethical kills at range. Now I know every animal, bullet, situation is different. So I want to hear from people that have pushed the envelope and see if we can gather the data to draw an educated conclusion because majority rules. If guys are seeing quick deaths on elk with impacts at or above 1,300 ft/lbs, then I would feel comfortable drawing that line in the sand and saying it is unethical to shoot at an elk at a distance where I do not have a minimum of 1,300 ft/lbs. Same thing for deer. Do we need 1,000, 800 ft/lbs... what is the reliable limit?

 

[BoomFlop]

I don't think you have a valid question with the answer you are looking for.

Bullet velocity creates the expansion of given bullet.

Energy is a factor of the specific bullet at that velocity.

Sectional density would also come into play as frontal area will also have an effect

So the answer to your question has far to many variables to provide an answer.

The simple answer would be, a bullet that is traveling fast enough to initiate expansion while providing enough penetration to cause enough blood loss to kill the animal.

That is my opinion.

Steve

 

[MTbackwoods]

I'm more looking for the kind of shot where the animal doesn't have to bleed out. The transfer of energy from the bullet to the fluids and soft tissues of the animal (hydraulic or hydrostatic shock) is what puts an animal down in it's tracks. Barring a CNS hit of course. I'm just looking for experience where guys have pushed the envelope with long range projectiles like the Berger and ELD where they maintained necessary velocity but were below the "recommended" energy of 2,000-1,200 ft/lbs depending on which article you read or which professional you choose to believe. I'm after real world data. To illustrate my point, there are reports of police officers that shot a suspect in the thigh with a hollow point and the energy transfer into his blood traveled to his brain and killed him instantly. That's energy transfer. I know there is no one size fits all answer. That's why I'm trying to get real world data from people so we can try to draw our own conclusions

 

[Zen Archery]

This guy has done a lot of great work in this field from down under.

Extensive Field-Tested Rifle & Cartridge Research - BallisticStudies.com

Expert rifle & cartridge research, carefully compiled through extensive field-testing & freely offered to the firearms community.

www.ballisticstudies.com

 

[HARPERC]

....I don't think you have a valid question with the answer you are looking for..........

Destruction of vital tissue is what matters.

I know of (first hand) of a man killed instantly by a .22LR fired from so far away witnesses, and shooter were unaware of the others presence.

Both humans and animals, can be very "fragile" one moment, then appear "indestructible" in another.

We're currently living in an absurd majority rules situation.

 

[MTbackwoods]

This guy has done a lot of great work in this field from down under.

Extensive Field-Tested Rifle & Cartridge Research - BallisticStudies.com

Expert rifle & cartridge research, carefully compiled through extensive field-testing & freely offered to the firearms community.

www.ballisticstudies.com

Yes I agree. I've watched and read a fair bit of his stuff. I like the cut of his jib. I thought of Broz but didn't even think about Nathan. Do you know of any of his articles or videos that speak more directly towards the thought I'm having?

 

[bigngreen]

The line between killing reliably with an energy dump or by bleeding out is relatively close if it indeed exists, I've seen very, very few elk just totally disrupted and dropped from a behind the shoulder mid body hit even with 3k of energy, I've seen antelope take a full round hows 300 Berger in a RUM and literally destroy everything inside them and they hold their feed and run 50 yards. Reliably killing with just energy I just have never seen possible, bleeding out from massive permanent wound channels are reliable, I've watched multiple elk wobble like 5 steps after taking a broad head with little energy, permanent bleeding wound channels are reliable!! I've kill a lot of elk well below 1000 foot lbs fast with no issues.

 

[MTbackwoods]

I don't have a true opinion on the matter so please forgive me if I pry. What kind of bullets were used that dropped the elk vs the bullets used that did not? If it was the same bullet, were there exit wounds on the animals that did not drop vs the ones that did? My thought process is that if 2 bullets have identical energy of 2,000 ft/lbs, one being say an AccuBond and the other a Berger VLD. The AccuBond passes through the animal and exits the other side with 800 ft/lbs of energy left. The Berger dumps all 2,000 ft/lbs into the soft tissues and organs of the animal. Shouldn't the Berger create more temporary wound cavitation and hydrostatic shock resulting in a more likely "drop" situation? And if that were the case, at what energy level do animals tend to stop dropping on impact?

 

[MagnumManiac]

Energy doesn't kill, tissue destruction caused by the velocity is what kills.
Let's say a 1lb lead ball is thrown and hits you with the SAME energy as a 200gr 30 cal bullet @ 3000fps in the chest. One you may survive, the other is very, very unlikely.

Do you see my point, energy alone imparts an impact, nothing more.
Without velocity, bullets do little damage.

Cheers.

 

[LaHunter]

I understand the basics of velocity and energy on target. I know that velocity is necessary to cause expansion and energy is the bullets ability to displace fluids and create hydrostatic or hydraulic shock. I know the basic principles. I know this question isn't coming across quite right so I'll keep trying to word it until I can get it across correctly. As long as the bullet being used is impacting at or above the recommended velocity, at what point does the energy, or lack there of, become more important than the velocity itself? So let's pretend that the bullet is always going to expand reliably, what amount of energy is going to prove to be lethal on elk, deer, etc. For example, let's say I shoot a bull elk at 1,000 yards behind the shoulder and he drops dead in his tracks and the bullet had 1,300 ft/lbs of energy. Now let's say in a different world that same bull is at 1,100 yards and I put the same bullet in the same spot yet he walks away because the bullet only had 1,150 ft/lbs of energy. So 1,300 ft/lbs would be the threshold for *Rule 1 Violation*al kills at range. Now I know every animal, bullet, situation is different. So I want to hear from people that have pushed the envelope and see if we can gather the data to draw an educated conclusion because majority rules. If guys are seeing quick deaths on elk with impacts at or above 1,300 ft/lbs, then I would feel comfortable drawing that line in the sand and saying it is unethical to shoot at an elk at a distance where I do not have a minimum of 1,300 ft/lbs. Same thing for deer. Do we need 1,000, 800 ft/lbs... what is the reliable limit?

In my opinion, there is not a clear 'line' of enough or too little. My rule of thumb is to have more than enough cartridge for the job. There are way too many variable involved to give you an answer. Not really sure why this is even of interest. When it comes to killing animals effectively, quickly, & humanely, it comes to shot placement and using enough cartridge and knowing the limits of your skill and your cartridge. If you are concerned about killing effect of your cartridge, you may need to get a 'bigger gun', assuming your skill level is adequate.

 

[JASmith]

Think of the difference in response of a pint water bottle when center punched by a .223 versus a 5-gallon water jug. The pint bottle literally explodes while the jug tends to grunt.

The apparent massive disruption depends on the relationship of the bullet's energy, the size of the animal, and how close the hit is to being a grazing shot. This last refer to the shot path being close to the skin, which allows expansion, stretch, and rupture.

These things tend to scale with size. So, a 550 gr bullet traveling at 2700 fps should have about the same effect on a 10 gallon can as does a 55 gr 2700 fps bullet hitting a 1 gallon jug assuming both are jhittingthe center. BUT, that lighter bullet hitting so it slides within a couple of inches along the sde will give an apperently explosive effect.

Things get more complicated when live animals are involved.