Needed Energy for killing.... is it a myth??



I'm on vacation but still manage to check this board and e-mail...

This is kind of a continuation of Shaky's thread and somthing I posted..

I have always been somewhat of a believer in needed energy for killing but a few people I respect posted otherwise...

I am a fanatic on accuracy and shot placement so I am on that band wagon..I'd like to hear ( read ) your thoughts on energy needed to efficiently kill an animal, any data ( real world experience ) to back this up would be great...

I feel we have enough wealth of knowledge on this board to discredit or reverse the data and preachers that you need tons of energy to kill and thats the only way to kill...

I'm very interested and curious about this...

Darryl Cassel

Well-Known Member
May 7, 2001

I "try" for a minimum of 1000 Foot Pounds of remaining energy and set my max range for that when possible.

We have killed animals cleanly with less then that & with complete pass through body shots though.

Have seen 750 Foot Pounds kill a large mule deer with the 250 gr MK from a 340 Imp case at 1800 yards.

Not sure what the minimum "can" be but, I don't like to go much below 1000 Foot Pounds.
That seems to have worked well for us over the years at extreme range.

Keep in mind, the heavier, higher BC bullets will retain energy much better then the light bullets will, "way out there". That's why we went from the 6.5/300 Weatherby up to the 7/300 Weatherby, to a host of Improved 30 cal cases to the 30/378 Weatherby and now into the 338/416 Rigby imp.--More retained energy in each jump of bore diameters and heavier bullets used in them.
The heavier bullet impacts can be seen much better at extreme range also.




I can only offer the data based on our penetration tests.

First I would say that bullet construction, geometry and materials all together do in fact make a difference in penetration or lack thereof.

Lets consider shape (bullet geometry): A blunt, wide meplat bullet has a wide frontal area already, this being the case it will meet more resistance then a pointy bullet.

Material: A jacketed, lead filled bullet is going to be more frangible than a bullet made from solid copper. Copper is tougher/stronger then lead.

A bullet made from solid copper, to a point, without a hollow point, will penetrate better, with less energy required, then a lead filled bullet of the same shape - considering other factors. The solid copper bullet will deform less then the lead filled bullet simply based on materials used - same design.

We conducted a test using a 210gr lead filled bullet that is manufactured/designed for high penetration. We loaded and shot this bullet out of a 338 win mag at 100 yards. We then loaded a 206gr EXP Groove Bullet for the same rifle with very similar velocities and shot it at 100 yards. Both bullets were shot into the same media. The 206gr EXP Groove Bullet had almost double the penetration of the lead filled bullet. The lead filled bullet opened much more then the 206gr EXP. This frontal area slowed the penetration - common sense. The 206gr EXP lost its petals, as designed, and the back of the bullet drove onward. Because the copper bullet, 206gr EXP, is made of solid copper it did not expand to anywhere near the degree of the lead filled bullet thus providing additional penetration.

That was a head-to-head example. Now I offer this data.

We took the same exact bullet, a 159gr EXP Groove Bullet, and loaded it up in a 300 win mag and produced a reduced load in a 30-06. Both were shot at 100 yards into the same media. The 300 win mag produced a velocity around 3200 FPS and the 30-06 (reduced load) produced a velocity around 2000 FPS. After shooting both into the same media the bullet that started at around 2000 FPS had almost the same penetration as the same bullet starting out at around 3200 FPS. Obviously the bullet starting at around 2000 FPS had less energy then the one starting at around 3200 FPS.

The reason that both had about the same penetration has to do with what physically happened, or didn't happen, to the bullet. The bullet launched at around 3200 FPS, upon impact, lost its petals, as designed, and the back of the bullet drove onward. The same bullet launched at around 2000 FPS did not loose its petals and did not loose much of its original form, retaining all of its original weight allowing it to penetrate to almost the same degree.

Conclusion: The fact that the bullet starting out at the higher velocity did in fact open up, causing for a larger frontal area, slowed its penetration. Although the energy played a role, its role was minimal.

These examples are why I don't hold much regard for a certain "energy" level to effectively kill any animal. There simply other variables that come into play.


6.5 Bandit

Well-Known Member
Mar 2, 2003
Elizabethville Pa
For regular white tail I like 800-900 fpe.. But this is all in how you look at it.. If you plan to punkin shoot one it doesnt have to be all that high.. Now im not sure what the fpe of a 22LR is (prolly under 150fpe @ 50yds) but if you punkin shoot one at say 50-100 yds they would drop like a rock.. For boiler room shots I would say @ least a good 800.. Then again if you hit them just right in the bolier room you could prolly get away with less then 800..

6.5 Bandit

[ 11-21-2003: Message edited by: 6.5 Bandit ]

[ 11-21-2003: Message edited by: 6.5 Bandit ]


Well-Known Member
Apr 27, 2002
Personally I don't know why energy became such a popular value to look at in determining wether an aminal will die or not. But I will throw out some real world data anyway.

The smallest value I have ever shot a deer with is 560fpe. This was a 547 yard shot with a 220 swift and 55gr bullet impact velocity was about 2150fps. Shot impacted one shoulder and hit a rib on each side leaving aproximatly a 1" exit hole. Dear went 20 yards and fell.

The smallest value I have seen a elk shot with was 525fpe. This was a 44mag rifle, shot was 250 yards. 265gr impacted at 945fps. Bullet hit high in the back but below the spine. Did not pass through. The elk fell immediatly upon impact.

These are exact opposite comparisons since one was a light bullet at high speed and the other was a heavy bullet at low speed. Make of it what you want, but both resulted in meat in the freezer.


Well-Known Member
Dec 11, 2002
I assume we talk big game here. I have some moose experience to share.

It´s not the energy, it´s what the bullet does with any given energy. Sometimes the good old Taylor Scale comes to mind,too.

Like,a sledgehammer and a 50 grain bullet, move them so that they have the same energy,say,1500..., hit something... see?

Also,energy goes both ways. While pulling the trigger,you receive the same amount of energy as the bullet has. If it´s the energy that does the job,nobody should be able to kill anything weighing more than the shooter -without passing out,huh?

Take a look in the link below,only one page of a huge examination,the rest can be found from some links on that page. I´m not trying to be smart,this is just very interesting.

Ahh... but: okay,I also have an opinion: I like heavy,large diameter bullets with some oomph left. But I want to know the impact velocity AND what I want to do with the bullet. Penetrate,expand,both and WHY?

I fluently use jacketed and cast bullets in a 45-70. If I need to stop:Cast 400 grains in the shoulder, if I want the best meat, a jacketed one ,sideways lungshot.


(I´m building a subsonic deer load right now, suppressors are legal here. Almost done, not much energy in a 400 grain sub bullet but man,does it stop! )

Mountain Man

Well-Known Member
Feb 18, 2003
Potter Co. PA
using energy values, and only energy values as a table for, or against, a round matters only to those who choose to believe it.

first off, above all else, shoot placement is everything. period.

second, bullet design is just as important as whatever energy its carrying. fmj's have plenty of energy- no expansion. ballistic tips have plenty of energy and expansion, but probably not the best for something like elk due to less penetration.

matchkings werent designed for hunting, but we all know what they can do to game. muzzleloader round balls just deform and dont carry much energy, but guys dump deer left and right with them around here. i've heard a 357 is too light of a revolver round for deer, yet i've put holes the size of quarters thru deer with it.

an arrow has hardly any energy at all, but relies on the wound channel created by the broadhead to do the work. bullets can work using the same method.

theres waay too much other stuff besides energy to take in to consideration. some rely on it solely, but i dont buy in to it.

energy is energy. while it counts for some, it has no direct correlation with performance.



Well-Known Member
Feb 8, 2002
Jackson MI
I too have my doubts about any one number telling you if you have enough bullet for the job. Some think that 1000 ft*lb is required, others feel comfortable with 800. But I have never heard anyone say that a 357 magnum pistol isn't up to the job and they only produce a little over 400 ft lbs at 50 yards.

I wonder if anyone ever did a test to see how much energy you can expend into a deer's chest? Sort of like an Izod impact test to see how tough steel is. I think a lot of variables would come out as more important than currently thought, such as impact velocity as Shakey mentioned. But once you punch through the deer, any remaining energy is wasted on the surroundings. So if a 308 will pass through a deers chest at X yards, why would you need a 300WinMag at double the energy? Do you like digging big holes? Now if you are shooting the 300WM at a range where the energy level is back down to the 308 level, that is great. But so many of the hunters I know carry 300WM's and would never consider shooting over 100 yards. I don't think the deer is going to be any more dead with a 300WM than with a 243 at that range, but I'll bet that the shooter isn't as likely to be as good with it.

I think that we may have gotten ourselves into a vicious circle. Someone speculates that X ft*lb would work. The next guy doesn't want to get caught short handed and so he pads his number 10-20% when asked what should be used. After a few of these we may where we are today. Nobody knows, but everybody comes up with a number.


I just got the pictures of the penetration tests I mentioned above.


The above bullet is a 159gr EXP Groove Bullet shot from a 300 win mag with a velocity of 3377 FPS, measured 10 feet from the muzzle.

The above bullet is a 159gr EXP Groove Bullet shot from a 30-06 with a velocity of 1808 FPS, measured 10 feet from the muzzle.

Both bullets were shot into metal cans, filled to the top with water, caps secured, stacked 1" apart in a line - at 100 yards.

As seen in the top picture the petals of the bullet came off, as designed. The Base of the bullet was found inside the 7th can.

As seen in the bottom picture the bullet expanded very little due to the low velocity. The bullet did not loose its petals. The bullet, as shown went through 6 cans and dented the front of the 7th can.

The penetration was almost the identical in both cases yet because the bullet shot from the 30-06, started out at such a low velocity it didn't deform much.

The energy levels of the 2 were drastically different. The fact that the top bullet expanded, slowed penetration.



Oct 9, 2003
Albuquerque, NM
From Petander:
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>... Also,energy goes both ways. While pulling the trigger,you receive the same amount of energy as the bullet has. If it´s the energy that does the job,nobody should be able to kill anything weighing more than the shooter -without passing out,huh?<HR></BLOCKQUOTE>

No, Petander, you do NOT receive the same amount of energy that the bullet has; you receive the same, actually a little more, MOMENTUM that the bullet has when it leaves the muzzle. You receive more momentum because the powder being expelled from the muzzle adds to the momentum. Momentum is mass times velocity. Energy is one-half times the mass times the velocity squared. A big difference.

[ 11-21-2003: Message edited by: CharlieK ]


Well-Known Member
Sep 10, 2001
Energy is of little concern to me. The above comments regarding .357 Mag and arrow performance illustrate the fallacy of using it as a benchmark. Placement and bullet performance are all that matter. Yeah, I know it takes energy to get there, but...

Perhaps the energy that is pertinent is stored in the amount of powder you burn. What you do with it is another story.

Jon A

Well-Known Member
Dec 28, 2001
Mukilteo, WA
Energy is important. With zero energy no damage would be done to the animal and you would not kill it.

But like everything else, it's only one factor of many that is important. You need to use a little common sense and not ignore other important factors like many of the examples given above illustrate.

Let's take Don's test for example. Same bullet, roughly the same penetration. Is that all that's important?

Which bullet did more damage to the cans of water? Which blew bigger holes through their sides? Which blew the lids higher in the air? Which would do more damage to the lungs of an animal?

Personally, I wouldn't shoot an animal through the lungs if the bullet was going to end up looking like the low velocity bullet pictured. Same bullet, it just didn't have enough energy to do any damage to itself (expand) and likely wouldn't do much damage to the animal. Give me an A-Max, BT, SST, SMK, AB, etc, bullets that don't need much energy to expand and inflict damage.

There's an example right there of how energy is important, but not the only important factor. If you're shooting an animal through the lungs at extremely long range, you don't need enough penetration to go through 3 or 4 animals if they happened to be standing side-by-side. You need to do damage to the first animal. One type of bullet may get that done with the same amount of energy that another wouldn't. You only have a little energy left, don't waste it.

Spitzer FMJ bullets are illegal to hunt with in most states for that very reason--they can pencil through the lungs punching only a tiny hole and increase the likelyhood of wounded game getting away. I used X bullets a lot in the past and light ones at high velocity were devistating at normal ranges. However, since I've become more proficient at longer ranges, I don't really trust the solid copper bullets to open up and do much damage when the range gets long.

I should say that's only from my own testing with X bullets. I haven't tried Don's or other solid copper bullets. But my personal preference will be to stay with plastic tipped bullets for a while, I think.


Looking at energy as a means of penetration, using the bullets shown above it can be determined that energy means little. The "needed" energy to open up a bullet is another matter. If one bullet "needs" 500 fpe to open up and another "needs" 800 fpe to open up then those are the numbers we should consider, not that any bullet requires a certain fpe to be an effective killer of a certain animal.

The lower picture shows the bullet hitting the cans at about 1600 FPS. Our purpose of that test was to find the threshold of where the bullet opens up. Obviously it is higher then 1600 FPS. A smaller caliber bullet with a thinner cross section wouldn't require as much energy to open up. This is why one should consider bullet construction, materials and shape more so then just energy created.

There is no doubt that both of the examples listed (pictures) show that either of those would go clean through an elk, double lung, broadside. It is also true that the top picture results would cause more trauma then the lower picture shows.

My purpose of the 2 pictures was to disprove that energy does not equal penetration. I believe the 2 pictures and data obtained prove that.


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