What energies are required for clean kills?

[stink belly]

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

[TerryM]

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.

[DM]

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

[bigbulls]

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.[&:]

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.

[Briman]

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.

[eldeguello]

ORIGINAL: Briman

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.

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!

[stink belly]

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.

[Briman]

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.

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.

[oldelkhunter]

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) 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.