What energies are required for clean kills?
 

What energies are required at the point of impact for clean kills on big game animals (deer, elk, moose, brown bear, caribou)?

RE: What energies are required for clean kills?
 

For deer and caribou 1000 ft/lbs is a good start. For moose and elk I would say 1800 ft/lbs and up. For the big bears I would say that biggest round you can shoot with the .300 mags as an absolute minimum.

RE: What energies are required for clean kills?
 

Personally, i don't think you can use energy as a guide!!!! There are many other factors to consider, and penetration is a big one!!

BTW, a 7mm Rem. mag with 175 Nosler partitions will easily out penetrate most all the 30 cal expanding bullets out of a 300 Win mag., and i've seen guys knock a brown bear FLAT with a 7 mag.. I just don't agree that a 300 Win mag is "ok" for brown bears, and a 7 Rem mag isn't!!!

I once flattened a "big" brown bear with a 264 Win mag my self, and i've also seen a few killed with a properly loaded 30-06!!

Drilling Man

RE: What energies are required for clean kills?
 

KE is a very very small part of the total factors in regarding clean kills on big game.

Two things that are far more important are bullet construction, and shot placement. A 100 grain .25 caliber varmint style bullet at about 3200 fps vs. a 300 grain hard cast 44 caliber bullet fired at about 1100 fps. Which is the better hunting round? Even though the 25 caliber bullet has more energy at 400+ yards thant he 44 mag does at the muzzle the 44 mag is still a far superior hunting bullet than the light varmint style bullet in the 25-06.

With the right bullets and assuming that the bullet is going where it is suppose to go you only need a couple hundred foot pounds for deer size animals and for elk and moose that figure would only jump to 800 or so.

For big bears like brown and polar bears and connsidering that they can and will bite back I agree that I would want the biggest chunk of lead traveling it the bears direction. But Thousands of foot pounds are certainly not required here either.

It takes a heck of a lot less energy than most people think or want to admit. Heck if we all agreed that a couple hundred foot pounds is plenty effective on deer then we wouldn't need to use and of the lightning fast magnums that so many people like to use on 100 pound animals.[&:]:eek:

Bottom line is if you use the right bullet and put it where you are suppose to then KE is a non issue with big game rifles.

RE: What energies are required for clean kills?
 

I agree with DM and Bigbulls.

I think alot of people put way too stock in Kinetic energy and not enough in bullet design.


I took my son to the zoo a few weeks ago and eyed up some of the 'big game' there. From the looks of things in real life, there is no reason why a properly loaded 30-06 couldn't easily take a Grizzly, though I wouldn't consider a .375 H&H to be overkill either. Ditto with the Hippos and Rhinos, though I think I would err on the high side of a .458 winchester magnum because they could stomp me into instant pudding if my shot wasn't perfect.:(

RE: What energies are required for clean kills?
 

These guys are 100% correct! KE is NOT a reliable guide to killing power! Neither are the myriad other schemes various people have invented to allow one to caluculate what is necessary for clean kills on various species. I include such theories as John Taylor's "knockout values", Elmer Keith's "pounds-feet", etc., etc. in this category. There are just too many variables involved! Bullet construction, shot placement, bullet diameter, impact velocity, bullet weight, sectional density, and even whether or not the animal is relaxed or hopped up on adrenalin when the bullet lands, and other factors as well, all influence what happens.

The only value there is to any of the calculated indexes of bullet power is that the figures allow you to compare cartridges using bullets of like construction. Once you start using these figures to decide whether a given load will reliably kill a given kind of animal or not you are enroute to a smare and delusion! For example, if you compare two different 7mm cartridges firing a Remington 175-grain Corelokt bullet, one of which produces 3000 foot-pounds of energy and the other a mere 2000 foot-pounds, one might reasonably conclude that the one carrying the higher energy level would be a better killer of, say elk or moose, than the other load. In fact, it is entirely possible that the velocity needed to get the 3000 foot-pounds is too high for adequate penetration due to bullet construction, and that the load having only 1500 foot-pounds actually performs better on the elk or moose!

There is a book by Bob Hagel called "GAME LOADS AND PRACTICAL BALLISTICS FOR THE AMERICAN HUNTER" Get one!! It will answer your questions about killing game animals with a rifle! Probably the best, "FAIR AND BALANCED" treatment of this subject ever written!

RE: What energies are required for clean kills?
 

It is obvious that bullet placement and bullet type are extremely important, but for comparison between reloads of a particular caliber for a particular animal, kenetic energy is an extremely important factor in the clean kill of an animal. Kenetic energy is based on the bullet velocity and weight which are both directly related to the penetration, performance, and killing power of a particular bullet.

The following was taken from www.chuckhawks.com

Kinetic energy

Energy, the ability to do work (or damage in the case of a bullet fired from a rifle) is an important component of killing power. It should be obvious to practically anyone that a bullet carrying more energy when it hits the target has the potential to do more damage than a bullet carrying less energy. Energy is what powers such important functions as penetration, bullet expansion, and tissue destruction. In the U.S. it is measured in foot pounds (ft. lbs.).

Kinetic energy is the most commonly used measure of a rifle's "power." It is the figure(s) listed, along with velocity, in practically all ballistics tables. It can be computed quite easily and is essentially the product of a bullet's mass times its velocity squared. If you want to calculate a bullet's energy at home, multiply the square of its velocity (in feet per second) by the bullet's weight (in grains) and divide by 450,400.

Energy is a pretty good rough estimate of killing power as long as you are comparing two reasonably similar rifle calibers and bullets that are not too dissimilar in sectional density. Compare a 200 grain bullet fired from a .35 Remington rifle to the same bullet fired from a .350 Remington Magnum rifle and you will find that the .350 Magnum caliber rifle is more powerful--its bullet carries more energy to the target. This squares quite nicely with reality, as the .350 Rem. Mag. has proven to have greater killing power.

Compare a 130 grain bullet from a .270 rifle with a 150 grain bullet from a .30-06 rifle, using standard factory loads, and you will find that at 100 yards the .270 bullet is carrying 2225 ft. lbs. of energy and the .30-06 bullet is carrying 2281 ft. lbs. (Remington figures for Core-Lokt Pointed Soft Point bullets). The Remington Core-Lokt bullets for the two calibers are very similar in performance, and those are very similar energy figures, so you would expect the two rifles to be essentially equal in killing power. Decades of use on big game have proven that the two calibers and loads are indeed just about equal in killing power.

Kinetic energy figures can be misleading, however, if dissimilar calibers and bullets are compared. The same Remington ballistics table that provided the energy figures for the .270 and .30-06 loads above also shows that the .30-30 factory load using a 150 grain Core-Lokt bullet carries 1296 ft. lbs. of kinetic energy at 100 yards. It also shows that the Remington .22-250 factory load using a 55 grain Power-Lokt varmint bullet carries 1257 ft. lbs. of energy at 100 yards. Does that mean that the .22-250 is approximately equal to the .30-30 as a deer and general CXP2 class big game cartridge?

Absolutely not! While the energy figures are comparable, the sectional density, frontal area, penetration, bullet performance, and consequently the killing power are completely different. Experience has proven that the .30-30 with the 150 grain Core-Lokt bullet is an excellent CXP2 class game cartridge, and the .22-250 with the 55 grain Power-Lokt bullet is woefully inadequate. The .30-30 and .22-250 are too dissimilar to compare on the basis of kinetic energy.

Energy is an important, but not the only, indicator of killing power. Cartridges that do not develop adequate energy are unlikely to place very high on any rational killing power list.

RE: What energies are required for clean kills?
 

Yes,yes kinetic energy, blah blah blah. 2000ft lbs of energy sounds pretty impressive does it not? It sounds like it would hit a a deer like a truck. In reality, the bullet doesn't hit an animal with anymore force than the stock of a rifle hits your shoulder.

There are several cartridges out there that have relatively low kinetic evergies such as the 7x57 and 6.5x55 that perform much better in real life than what the numbers suggest. There have been professional hunters in the past that have taken every type of big and dangerous game many times over with even lesser cartridges than these but of the same caliber.

RE: What energies are required for clean kills?
 

What everyone says here is somewhat true. But the energies are a guideline. Along with taylors theory and elmers. But its the only scientific one that is undisputed. Another piece of information to help make your decision. I know if I don't have over 900ftlbs of energy from a hollow point bullet from my 50 cal muzzleloader, I won't get a passthru most likely, which I want. So understanding energy helps me make a decision. I would rather hit a moose with a 180gr barnes with 2000ft lbs of energy than a bullistic tip with 2500ft lbs. Therefore understanding energy and bullet construction helps me make a decision. All things have to be considered.

RE: What energies are required for clean kills?
 

I read about some stunt somewhere where someone held a piece of steel plate in front of themselves and a friend with a 458 shot at the plate. It moved the plate a few inches and that was it. Hopefully they preshot the plate before the person stood behind it. I guess most people would have thought that man would be knocked over based on all the kinetic energy unleashed on that plate.

In reply to your question most experts pick (big stick for deer):D or 1000lbs and that holds true for CAribou and probably 2000 at the target for Bear,Elk and Moose. I am positive all three have been killed by lesser cartridges bearing less energy . I think its all related to the speed which a bullet transfers energy to internal organs on its way through the animal that makes the difference.

RE: What energies are required for clean kills?
 

Problem with energy is alot of gunwriters don't know what it is. I read in G&A once that energy is false and if it was true, then hitting a deer would be like hitting something with a car and make the deer fly in the air. What was was mistaken about is energy of the car. If the steel plate was hardest material in the universe and did not deform any at all. And the bullet was indestructable and did not change shape in any way when hit, then at that moment when it hit the target, there would be 2000ft-lbs of energy at that instance. But the change in bullet shape uses up alot of energy. The decelleration when entering the deer uses up considerable amount of energy.

RE: What energies are required for clean kills?
 

I have that book by Bob Hagel. Great reading!

RE: What energies are required for clean kills?
 

if you want to rate your bullet by its energy fine, But a .223 is the smallest centerfire allowed for deer in most states also has a low bullet energy a 60 grain 223 only has about 1200 ft lbs at the muzzle and only about 900 ft lbs at 100 yards. But if that .223 is placed right it will kill a deer just as good as a 30-06, Basically what I am saying bullet energy doesnt matter when your shot is placed right. A friends grandfather that I used to hunt with uses a 25-20 in a old winchester model 94 at 100 yards the bullet has only about 300 ft lbs of energy I watched that old man cleanly kill many deer with that 25-20 over the 4 years I've hunted with him and his grandson.

RE: What energies are required for clean kills?
 

The thing you have to remember about energy is that it doesn't mean anything BY ITS SELF! 3000 ft/lbs is alot of energy if its in a 250gr .338 bullet, its not if its in a 200lb cannon ball. Another misconception is that caliber doesnt matter. if you put 3000 ft/lbs of energy into a projectile that is ,say 1/100 the size of a sewing needle weight and caliber both(assumeing it's unbreakable). it could pass through your forhead and not drop you. Thats exactly what radiation is, it only hurts you when you get billions of them at once and get a "shotgun" effect. Energy means alot when coupled w/ 1)bullet diameter 2)bullet construction. DM - First I'm not hacking on your 7mag, its a fine caliber, but you need to compare apples to apples. You cant compare 300win-180gr- $12/box factory loads to 7mmrem mag w/ 175gr nosler partitions. 1) bullet weights - 180gr is avg weight for 300, 175 is heavy for caliber in 7mm 2)also nosler partitions are a premium bullet, designed for big game. For a real comparisn you should have partitions in both and about 225 gr bullet in the 300(heavy for caliber). I gaurantee with ALL things being equal the 300win will out penetrate the 7mag. Having said that, If you have handloaded your 7mag as we mentioned before you may be right that your as gunned up as the guy who goes out w cheapo factory ammo in a 300, but that guy does have more gun than if he had a 7mag w/ cheapo ammo. As for 7mm and griz... I dont shoot em , so I'd ask some guides who see dozens of em shot each year.

RE: What energies are required for clean kills?
 

The excerpt from Chuck Hawkes essentially stated that KE is only useful when comparing similar things, and that it is misleading when comparing dissimilar things.

So then, there is no answer to the original question on what KE is required to produce clean kills. More info. is required. You neeed to know bullet caliber and design (weight, construction, etc.).

I have shot deer with a 45/70, loaded with rem. 300 gr JHP bullets driven to roughly 2000 fps. One smallish 6 pointer trotted on past while I unloaded on him, and only fell down because my last shot was a neck shot as he was going straight away. I hit the deer 4 times in all, twice in the ribs. There is no way that deer should have soaked up all that KE. But the bullets basically failed, as the jackets were not constructed heavily enough for that velocity. I didn't get one pass-through. KE is in fact the bullet's potential to do work, but other things contribute to it's actual ability to do the work correctly.

RE: What energies are required for clean kills?
 

One of the things one should note, as pointed out by oldelkhunter here in his story about the guy holding the plate that was shot with the .458, is that these "foot-pounds of energy" ("ONE FOOT-POUND MOVES A POUND OF MATTER ONE FOOT") aren't REALLY really foot-pounds at all! If it were, "5000 foot pounds" would move a 100-pound animal 50 feet from where it was when hit! It doesn't.

As pointed out by Briman, "In reality, the bullet doesn't hit an animal with anymore force than the stock of a rifle hits your shoulder." So what does this figure do for us? It allows a kind of comparison between calibers which are using bullets of identical construction that are travelling at comparable velocities. When the velocities of calibers being compared differ significantly, such a comparison becomes invalid, because projectile behavior changes so much. For example, a shotgun slug or ML bullet travelling in the range of 1000 to 1500 FPS kills by hemorrhage, just like a broadhead arrow, and has little shock effect. Hence an animal shot with one will keep travelling until it bleeds out, unless some critical structure like a leg, shoulder, or spine is destroyed, preventing it from travelling. When velocity moves into the 2500+ FPS range, things seem to change, and animals shot with bullets going much faster than 2500 FPS usually travel a lot shorter distance from where they are hit, if the hit is anywhere near a vital spot.

I get a kick out of people who maintain "you must have a minimum of X number of foot pounds to kill a Y animal," etc., because such statemewnts are patently ridiculous. They totally ignore all the other significant variables in the killing power equation!

RE: What energies are required for clean kills?
 

Brimans assertion that the bullet only hits as hard as the stock hits your shoulder is as wrong as opening a brothel in a church. There are alot of ways that the energy you get hit w/ differs from what the animal gets hit w/. Gases vent preasure, muzzle flip, heat, noise, brass forming, all of these plus probably a thousand more all disipate energy in different ways, it also ignores the main point, surface area over which the force is applied. If you dont believe me take 22lr bolt or single shot, it wont kick at all right? drill the stock and insert a 1/4 dowl(slightly smaller than a pencil), put the dowl up to your nose, put the gun on a rest so that nothing but your nose(through the dowl) recieves the recoil. Tell me what happens. Name and address withheld to protect my hide after you try this.:D

RE: What energies are required for clean kills?
 

You can have a stock that is only a 1/4" dowel or even a needle- it will still hit you just as hard as a regular stock, though penetration will me much greater.

I'll reword my stance- a bullet hits with LESS force than the stock of a gun as it will loose momentum from heat, friction, wind resistance, etc, not to mention that some of the recoil you feel is nothing more than the mass of the gasses created by the burnt powder ejecting from the gun which do not hit the target at all.

RE: What energies are required for clean kills?
 

Mike, in response to your colorful assertion, let me refer you to Newton's Third Law of Motion.

RE: What energies are required for clean kills?
 

Eldeguello in responce to your post, let me point you to Newtons laws also. Equal and opposite reaction is used to a point here too. Not true that 5000ft-lbs would they a deer 50ft. For that assertion, no energy would be used or lost with the crushing of the bullet. No energy would be lost entering or penetrating the deer. The deer would have to be infinately hard and so would the bullet. Misusing physics just a tad here. You won't believe how much energy is lost just from the deformation of the bullet. Try a test. Get two pool balls, and smack one against another at rest. See the distance moved. Now put a 1/4 cotton on the one to smack it, do the same thing. Enormous amount of energy lost. Also pool balls are close to ideal as a person can reasonably get. If they were infinately hard, the effect would be ten fold as they deform also.

RE: What energies are required for clean kills?
 

if you use the right size rifle for what your shooting at your shot placement is what you need to be concerned about not the ft/lbs.

RE: What energies are required for clean kills?
 

eldguello - opposite and equal is exactly what I was getting at. the bullet does not contain 100% of the energy, and the very nature of a firearm, deflects the energy in MANY directions not just straight back and straight forward, give me the vector resolutions on ALL the different vectors that the energy takes and add them up ,then you have opposite and equal. the biggest change is in the recoil pad , this absorbes alot of energy that is sent in your direction when shooting.

RE: What energies are required for clean kills?
 

Briman - you have me on a technicality there;) you are correct, the size of the stock does NOT change the force you get hit w/. Let ME refrase my stance : the stock the size of the dowl WILL strike the point of impact MUCH harder than a normal stock, changing a harmless nudge into a $#%^&@* whack in the nose.

RE: What energies are required for clean kills?
 

You are right, of course! The factors you mention are all involved. That's why the "foot-pounds" business is so meaningless in determining killing power! It's HOW THE ENERGY IS USED that determines what happens when a living thing is shot, rather than HOW MUCH ENERGY THERE IS, as calculated by some arcane formula.!!

RE: What energies are required for clean kills?
 

True! But MOST of the energy is moving fore and aft in the form of the weapon (to the rear) and the bullet plus propellant gases to the front. Your statement shows PRIMARILY that the bullet will strike with LESS force than an amount equal to that pushing to the rear!

RE: What energies are required for clean kills?
 

After it absorbs energy, where does it go? Remember, energy cannot be created or destroyed.

Answer: It stores energy and then releases it over a longer period of time.

Recoil pads are for sissies anywhow;)

RE: What energies are required for clean kills?
 

Think in one day, maybe not in our lifetime, they will have a real formula that has been thought about with men of knowledge, that takes into account diameter, rate of expansion, size of expansion dependent on speed and media, velocity, wieght to give an accurate number. It might happen. I work in fiber optics these days, and we have an extremely complicated nonlinarity formula that takes a super computer/Sun machine to run to predict the outcome of light traveling 1000's of miles.

The reason we might not come up with a fomula in our lifetime, is one, no money in it, two, do we really need it other than chewin the fat here. I mean, we have something better, real life data and 100's of years of it.

RE: What energies are required for clean kills?
 

No, we don't, other than for discussion purposes!

RE: What energies are required for clean kills?
 

Good point , but its still interesting to yak about:D I did however run into an article that originated in Africa. Seems some veterinarians were hired to cull herds. They documented how each animal went down, ran, exact yardage ect. The same 2 rifles(different cal) were used for the entire time. The coolest part was that they medically disected EACH animal. What they found was that the animals that dropped in their tracks all had massive brain hemmorrages. animals w/ near identicle wounds died in dramatically different fashions, the quick one always had brain hemmorrage. The conclusion they came to was that the heart was consrticted(high point of your blood preasure) at the exact time of impact of the bullet, which created a hydrostatic preasure spike in addition to already being at the natural highest preasure in the circulatory system and thats what caused the brain damage, which caused them to drop in their tracks.

RE: What energies are required for clean kills?
 

I was reading on an african hunter website about using the 303 British to go after lions. Supposedly better than shotgun slugs at close range. I'd also like to have seen the Swedes popping polar bears with their 6.5 x 55. I would look for heavier pills but the legends live on.

RE: What energies are required for clean kills?
 

NVMIKE I read that article too. Many years ago I worked with a group that did that kind of studies. It does give one explaination for what we have all seen happen. That is for an animal to keep going after shot after shot hits them and the next one drops like a rock after one shot from even a smaller weapon. It goes to show that everyone here is right to an extent. There are many many factors that come into play. The most certain is going back to useing the right bullet with enough power behind it to drive it to and through something vital and most important, It can't do the job without proper shot placement. This is absolutely the number one priority.