Bullet lethality: energy and velocity

[jpndave]

Just for sake of argument in this exercise in futility. Does the VLD really dump 2,000 foot lbs? If the VLD comes apart into smaller pieces or shrapnel can it still dump the energy as smaller projectiles versus the accubond continuing on as one solid mass. I would think mass of the object would figure in. We need a physics guru on this one.

If you don't have an exit, the entire remaining energy is dumped. Where and how that happens can certainly be different but the energy has to go somewhere. If the bullet stays so does the energy.

Nathan's write-up others previously mentioned that I linked above is really good.

 

[Calamity]

MTBackwoods-I would like to offer my opinion, for what it's worth, and some factual anecdotes to give it context. IMO, you cannot find a specific answer unless you specify caliber, bullet, point of impact, organ damage and a lot of other variables. Maybe not then. I will allow one circumstance where that is not true; i.e., if you shoot an elk anywhere in the body with a 106mm recoilless rifle, it will be a one-shot , dead in his tracks, kill! No question. But, for standard hunting rifles, I stick by the former opinion. The following anecdotes are facts: A .357 magnum handgun has about 600 ft-lbs of energy, but park rangers have killed charging grizzly bears at point-blank range with that gun. A .44 magnum handgun has a bit over 1000 ft-lbs of energy at the muzzle, and Thell Reed Jr. killed an Alaskan brown bear with one. During the Great Depression, more white-tail deer were killed with the .22 long rifle cartridge than all the other hunting rifle calibers combined. It has around 135 ft-lbs of energy. I have also seen deer gutshot at 50 yds with a 30-06 jump a fence and run for half a mile before collapsing and dying slowly. That is close to 2800 ft-lbs of energy. So, if you must have a sure thing, the Marines may be able to scare up an Ontos for you. It has six mounted 106mm recoilless rifles, and can remove the side of a mountain on a good day.I hope this helps.

 

[AlphaDogs]

My goodness ! What ever happened to: Select a bullet that will expand and hold together at the range you are shooting, makes two holes in the animal and put that bullet through both lungs ? If you do that, the animal will die.

Never seen an exception to that.

 

[MTbackwoods]

This write is the best I have seen on that particular question.

Effective Game Killing

Effective game killing- How bullets kill and where to aim to ensure a fast clean kill.

www.ballisticstudies.com

Yes! That is more of the information I was looking for. Though it doesn't quite answer my question, it certainly provides a ton of data and information that lends itself toward the effect of energy and it's ability to cause rapid death on animals. Thank you for that share.

Just for sake of argument in this exercise in futility. Does the VLD really dump 2,000 foot lbs? If the VLD comes apart into smaller pieces or shrapnel can it still dump the energy as smaller projectiles versus the accubond continuing on as one solid mass. I would think mass of the object would figure in. We need a physics guru on this one.

My understanding of that scenario would be this: if the VLD comes apart in the animal, it is effectively losing it's mass which would in turn cause it to lose momentum (velocity). In the process of doing so, it is transferring more of it's energy into the tissue of the animal through the loss of mass and subsequently velocity. Therefore, the frangible bullet would indeed transfer more of it's energy into the target vs the AccuBond that retains more of it's mass and speed

 

[MTbackwoods]

MTBackwoods-I would like to offer my opinion, for what it's worth, and some factual anecdotes to give it context. IMO, you cannot find a specific answer unless you specify caliber, bullet, point of impact, organ damage and a lot of other variables. Maybe not then. I will allow one circumstance where that is not true; i.e., if you shoot an elk anywhere in the body with a 106mm recoilless rifle, it will be a one-shot , dead in his tracks, kill! No question. But, for standard hunting rifles, I stick by the former opinion. The following anecdotes are facts: A .357 magnum handgun has about 600 ft-lbs of energy, but park rangers have killed charging grizzly bears at point-blank range with that gun. A .44 magnum handgun has a bit over 1000 ft-lbs of energy at the muzzle, and Thell Reed Jr. killed an Alaskan brown bear with one. During the Great Depression, more white-tail deer were killed with the .22 long rifle cartridge than all the other hunting rifle calibers combined. It has around 135 ft-lbs of energy. I have also seen deer gutshot at 50 yds with a 30-06 jump a fence and run for half a mile before collapsing and dying slowly. That is close to 2800 ft-lbs of energy. So, if you must have a sure thing, the Marines may be able to scare up an Ontos for you. It has six mounted 106mm recoilless rifles, and can remove the side of a mountain on a good day.I hope this helps.

We have our answer ladies and gentlemen! Lol. Fair enough. As for a specific caliber, I don't really want to restrict the conversation in that way. Some guys use 6.5 or 7mm and others .308 or .338. If you were to use a Berger VLD in all of those calibers, at an impact velocity of say 2,000 FPS, you are going to see pretty similar results. Given that the projectile is in the same class as far as weight by caliber. Now granted, the larger diameter bullet should have an advantage to a degree because of mass. However, the actual physical performance of the bullets should be pretty similar in the soft tissue. The .338 should have a larger damage field because of more physical mass to shed, but let's assume sectional density is near identical for all 4 bullets. On game performance should be reasonably similar. Not identical, but similar. Where my interest comes in, is where each of those bullets at the same velocity would have different levels of energy. The .338 is going to have substantially more energy to dump due to mass. Therefore one could be safe in assuming the .338 would have a higher probability of a "dropped" animal than the 6.5 with identical velocities and shot placement. And let's say high shoulder for shot placement. So rather than saying "use the largest caliber possible". I want to know where the cutoff point COULD be for any caliber with similar bullets depending on energy. Obviously if a bullet has 2,000 ft/lbs of energy but only 1,400 FPS when it needs 1,800 FPS to open reliably, one must make his cutoff point where the bullet reaches 1,800 FPS. But on the flip side, the smaller bullet could still have 2,000 FPS but only be carrying 800 ft/lbs of energy. Would we then need to make the cutoff point where the bullet had 1,000 ft/lbs or 1,200 for/lbs?

 

[MTbackwoods]

My goodness ! What ever happened to: Select a bullet that will expand and hold together at the range you are shooting, makes two holes in the animal and put that bullet through both lungs ? If you do that, the animal will die.

Never seen an exception to that.

Dead is dead as far as the hunter is concerned. However dead is not dead as far as the animal is concerned. I am seeking a near instantaneous and painless death. If you read the article shared earlier by jpndave, it talks about the effects of energy on game. It's worth a read for anyone and everyone. And if we don't strive to learn and make things better, we end up never improving on anything and we might as well go back to spears and living out of caves. Good enough is not good enough for some. The pursuit of perfection should drive us all to be better

 

[Quintus]

Here is a try at it. First there can only be a recommended minimum in impact velocity and energy due to the variables in any given shot.
1. Point of impact - There are variables within the same "POI" ie Did you hit a rib or go between, was the muscle encountered relaxed or contracted, musculature of the individual, body fat % of the individual, bone density of the individual.
2. I can't prove this one, but I think it maters if the animal has just inhaled or exhaled and if the heart is drawing or pumping. We shot a lot of like sized pigs at same distances with same loads with seemingly same POIs with essentially same penetrations angles. Some would run like hell and some would crumble dead stiff legged. Most of these animals were mildly agitated but not wound too tight and were always shot standing.
3. Expansion depth/bullet construction - This one is directly tied to impact velocity, but there are also variations lot to lot in lead purity, jacket thickness, skiving, nose formation, and the exterior factors imposed on the bullet from variable one above.
Most animals regardless of the velocity/energy numbers will not drop at the shot unless there is either a direct CNS hit or the hydrolic shock is close enough to the spine to disrupt the CNS. Ultimately it is the hole, ensuing loss of blood, and lack of oxygen to the brain that kills.
Essentially, you are asking how to calculate what is actually "too far" for a given bullet. Since all the bullets, and all the animals, and all the atmospheric conditions, and all shot angles, etc. etc. will never be the same, it simply can't be accurately calculated. Thus you get safe published minimums for components that in most cases will be adequate plus.

 

[Orange Dust]

Here is a try at it. First there can only be a recommended minimum in impact velocity and energy due to the variables in any given shot.
1. Point of impact - There are variables within the same "POI" ie Did you hit a rib or go between, was the muscle encountered relaxed or contracted, musculature of the individual, body fat % of the individual, bone density of the individual.
2. I can't prove this one, but I think it maters if the animal has just inhaled or exhaled and if the heart is drawing or pumping. We shot a lot of like sized pigs at same distances with same loads with seemingly same POIs with essentially same penetrations angles. Some would run like hell and some would crumble dead stiff legged. Most of these animals were mildly agitated but not wound too tight and were always shot standing.
3. Expansion depth/bullet construction - This one is directly tied to impact velocity, but there are also variations lot to lot in lead purity, jacket thickness, skiving, nose formation, and the exterior factors imposed on the bullet from variable one above.
Most animals regardless of the velocity/energy numbers will not drop at the shot unless there is either a direct CNS hit or the hydrolic shock is close enough to the spine to disrupt the CNS. Ultimately it is the hole, ensuing loss of blood, and lack of oxygen to the brain that kills.
Essentially, you are asking how to calculate what is actually "too far" for a given bullet. Since all the bullets, and all the animals, and all the atmospheric conditions, and all shot angles, etc. etc. will never be the same, it simply can't be accurately calculated. Thus you get safe published minimums for components that in most cases will be adequate plus.

Agree completely especially #2. And NO, I can't prove it either, but I have seen enough critters die to be completely convinced you are right.

 

[vancewalker007]

The 2 longest shots on game I've been personal witness to were a 934 yard shot on a Coues deer and a 1092 yard shot on a cow elk. Both with a 7mm LRM. The deer was shot with a 175gr ELDx running about 3000fps. The elk was shot with a Berger 180gr VLD hunting. Technically they were both killed by the G7 I was using to range them with. Both shots were made by my son (he's grown), so I just had to get the range and wind call ;-).

The deer experienced a bullet traveling about 1930 fps with about 1400 ft lbs. The bullet performed (as far as killing) perfectly. It entered near the last rib on the right side and travelled in a straight line across the heart lung area at slight angle exiting the front of the left shoulder. I don't think it struck any major bone. The deer dropped on contact, DRT. We could see the deer with our glasses the entire time.

The elk was angling slightly head-to-the left. The bullet hit directly in the middle of a rib in the middle of the heart lung expanded a lot, disappeared, and the elk tipped over rolling down the steep hill she was on DRT. We could see her with our glasses. The VLD hit at about 1830 fps carrying about 1310 ft lbs.

In both cases the bullets were very similar carrying plenty of velocity to expand as designed and kill even though the ft lbs were not super high. Of course these are anecdotal, but I think the message is shoot a good bullet that will still have enough velocity at your personal max hunting range to expand properly into the heart lung area and you're likely going to have plenty of energy to get to vitals for a kill.

 

[fiftybmg]

I don't really think that emphasis should be placed solely on how much energy the bullet is carrying at a certain distance to make it a factor for choosing that particular round for hunting per se. I believe that you only need enough energy to carry the round the desired distance and than still have enough momentum to penetrate the target or prey in this instance. I believe this to be true , but if you do not, than explain why so many deer, elk , bears, and buffalo have been take with an arrow?

It cannot be compared to a bullet.

If you launch a bullet of equivalent weight to the arrow at the arrow velocity, penetration is minimal.

Hunting arrows are able to pass completely through. I've seen this on warthog.

 

[fiftybmg]

Every hunting bullet has it's minimum impact velocity for expansion as per the manufacturer, it's usually around 1850 fps.

The muzzle velocity is not the correct velocity to use to determine suitablility of a bullet.

The velocity of the bullet at the distance you are hunting is the right velocity to use.

There are calculators that can give you how fast a bullet is still travelling when it is a certain distance from the muzzle.

Calculate how far the bullet is from the muzzle when it is at the minimum velocity for expansion, and you have your practical hunting range limit.

 

[MTbackwoods]

Thank you vancewalker007 for the data and experience. That's what I'm after here. Field proven data. And I agree with Quintus. Especially on #2. The research conducted by Nathan Foster that was shared earlier by jpndave speaks to that. More or less. If muscles are tense, the animal is less likely to be dropped than one that is completely relaxed. And I think we can all agree that if you have an animal skittish at long range, you're probably doing it wrong lol. But what is long range any way? For some it's 400 yards. For others it might be 1,400 or more. My personal soft limit is 800 yards while my hard limit would probably be 1,000. All my rifles are capable of cleanly taking any game animal I pursue in Montana at those ranges and then some. But what if that perfect animal walks out into the perfect opening with the perfect conditions? We should all be prepared for that moment and I just wonder where I should draw the line for myself. And without going out and shooting tons of animals myself, I'm left gathering others data in order to try to draw a reasonable conclusion. Keep it coming though. No one is right or wrong on any of this. We all have different beliefs

 

[Quintus]

It cannot be compared to a bullet.

If you launch a bullet of equivalent weight to the arrow at the arrow velocity, penetration is minimal.

Hunting arrows are able to pass completely through. I've seen this on warthog.

Actually depending on the shape of the bullet you will still get deep penatration. What does the average hunting arrow with broadhead weigh? 500 to 700 grains? Shoot a 600 grain .416 pointed FMJ at 325FPS and impact a deer or pig at 20-30 yards I bet you get complete penetration even without cutting edges. Broadheads make huge wound channels, and blood sprays.

 

[FEENIX]

I don't really think that emphasis should be placed solely on how much energy the bullet is carrying at a certain distance to make it a factor for choosing that particular round for hunting per se. I believe that you only need enough energy to carry the round the desired distance and than still have enough momentum to penetrate the target or prey in this instance. I believe this to be true , but if you do not, than explain why so many deer, elk , bears, and buffalo have been take with an arrow?

Arrow kill with hemorrhagic shock while bullet kill with hydrostatic shock. Animal will expire differently.