How much Energy to kill a Deer?

jwp475

Well-Known Member
Joined
Feb 4, 2005
Messages
2,595
Location
USA
Very little "thermal" energy is transferred in the impact of a bullet on flesh and bone. Most of the enrgy is transferred in the deforming of the bullet and producing permenant and temporary wound channel.

Hope you're having a good argumentative day.
You are incorrect according to Dr. Martin Fackler President of The International Wound Ballistics Assc. and Duncan MacPhearson who has the only 100% accurate wound trauma ballistic model




 
Last edited:

MontanaRifleman

Well-Known Member
Joined
May 21, 2008
Messages
6,194
Location
South of Canada and North of Wyoming
Excuse me JWP, but where does the article you posted conradict anything I said????

Can you please provide me with data to back up your claim that most energy from bullet impact is transformed into "thermal energy" and when you've answered that, then please explain what forces cause bullet deformation and temporary and permenat wound channels?

Thanks...
 

jwp475

Well-Known Member
Joined
Feb 4, 2005
Messages
2,595
Location
USA
Buy the book as I id and read it and you will find it, are yo can surf the Physics web sights and you will find wht you seek



 

MontanaRifleman

Well-Known Member
Joined
May 21, 2008
Messages
6,194
Location
South of Canada and North of Wyoming
JWP, let me help you out with an illustrative object lesson...

Lets take, say a 300 g SMK fired out of your 338 Lapua (a fine cartridge gun))

OK... Said bullet is traveling downrange toward a 1" steel plate targert 50 yds from muzzle. The bullet arrives at said targert with a velocity of 2690 fps and and energy of 4820 ftlbs. A fraction of a second later, said bullet is lying on terra firma with zero velocity and zero energy. Does the steel plate target show any signs of significant temp change? Is there any sign of scorched or melted metal? Just what happened to all that energy???? Clue.... look at the shape of the bullet lying on terra firma and the crater in the steel plate. I'm guessing that's where the energy went to....
 

MontanaRifleman

Well-Known Member
Joined
May 21, 2008
Messages
6,194
Location
South of Canada and North of Wyoming
Buy the book as I id and read it and you will find it, are yo can surf the Physics web sights and you will find wht you seek

Nahhh.... I'm not buying the book and not accepting your BS. You stated that I was wrong according to blankety blank and posted two pages from some book that basically said nothing. I have reasearched the net and the info and data, some of which i posted for you in the other thread back up what I say, or more correctly, that's where I get my info, that and a basic understanding of physics.

YOU made a statement.... YOU back it up... else it is BS....
 

jwp475

Well-Known Member
Joined
Feb 4, 2005
Messages
2,595
Location
USA
JWP, let me help you out with an illustrative object lesson...

Lets take, say a 300 g SMK fired out of your 338 Lapua (a fine cartridge gun))

OK... Said bullet is traveling downrange toward a 1" steel plate targert 50 yds from muzzle. The bullet arrives at said targert with a velocity of 2690 fps and and energy of 4820 ftlbs. A fraction of a second later, said bullet is lying on terra firma with zero velocity and zero energy. Does the steel plate target show any signs of significant temp change? Is there any sign of scorched or melted metal? Just what happened to all that energy???? Clue.... look at the shape of the bullet lying on terra firma and the crater in the steel plate. I'm guessing that's where the energy went to....



Ballistic Pendulum
The ballistic pendulum is a classic example of a dissipative collision in which conservation of momentum can be used for analysis, but conservation of energy during the collision cannot be invoked because the energy goes into inaccessible forms such as internal energy. After the collision, conservation of energy can be used in the swing of the combined masses upward, since the gravitational potential energy is conservative.


Calculation
Index

Collision concepts
HyperPhysics***** Mechanics R Nave
Go Back



Ballistic Pendulum
 

jwp475

Well-Known Member
Joined
Feb 4, 2005
Messages
2,595
Location
USA
One foot pound equals about 1.36 joule, 0.32 calorie, or 0.0013 Btu.


Not enough heat to significantly raise the emperature
 

MontanaRifleman

Well-Known Member
Joined
May 21, 2008
Messages
6,194
Location
South of Canada and North of Wyoming
Ballistic Pendulum
The ballistic pendulum is a classic example of a dissipative collision in which conservation of momentum can be used for analysis, but conservation of energy during the collision cannot be invoked because the energy goes into inaccessible forms such as internal energy. After the collision, conservation of energy can be used in the swing of the combined masses upward, since the gravitational potential energy is conservative.


Calculation
Index

Collision concepts
HyperPhysics***** Mechanics R Nave
Go Back



Ballistic Pendulum
No.... this is not a ballistic pendulum. This is a bullet that strikes a steel target and falls inert to the ground with zero velocity, energy and momentum and the target is left standing. You are ignoring what happens to the bullet and the target. It takes a transfer of "energy" to deform both the bullet and the target. This is in fact where most of the energy goes.


One foot pound equals about 1.36 joule, 0.32 calorie, or 0.0013 Btu.

Not enough heat to significantly raise the emperature
We are not talking about 1 ft lb of energy, we are talking about 4800 ftbs. If most of that energy was transfered into thermal energy, it would blister your finger to touch the target or bullet. There is only a very slight amount of energy that is tranfered to thermal energy in this type of collison or when a deer gets shot. You will find zero data to back your claim.
 
Last edited:

justgoto

Well-Known Member
Joined
Apr 11, 2009
Messages
636
Location
Carrollton, Ohio
Every deer I have seen killed in one shot drt, 800ft/lbs was the least.

This year I will be trying my 357 and it starts out at 505ft/lbs; but I am pretty sure it will do the job if I do my part.
 

trueblue

Well-Known Member
Joined
Feb 18, 2008
Messages
2,312
Location
IOWA
So based on the posts so far, is there a statement or rule of thumb the average hunter can go by as a guideline.
Maybe something like:
Know what your bullets minimal fps is for expansion and still have 1000# of energy for deer, 1500# for elk, and use that to determine your max range for taking the shot.
 

J E Custom

Well-Known Member
Joined
Jul 29, 2004
Messages
10,320
Location
Texas
So based on the posts so far, is there a statement or rule of thumb the average hunter can go by as a guideline.
Maybe something like:
Know what your bullets minimal fps is for expansion and still have 1000# of energy for deer, 1500# for elk, and use that to determine your max range for taking the shot.

This is the best guide line to use.

It is based on the Taylor knock out values and has been the standard energy to recomend
for good clean one shot kills. This does not mean that less will not do only that 1000 ft/lbs
for deer size game and 1500 ft/lbs for Elk size game works most of the time if the shot is well
placed. 2500 ft/lbs is recommended for animals weighing 1500 pounds and 4000 ft/lbs + for
dangerous game for obvious reasons.

The main thing is to use a bullet at or above it's designed velocity and energy so as to get the
best performance from it under ALL hunting conditions. So to sum it up if you are hunting deer
size game you want to look at your ballistic tables and find the distance where the bullet drops
below any of the aforementioned values (1800 ft/sec,1000 ft/lbs of energy or accuracy is
insufficient to make a lethal hit) and just limit your distance to less than the max you will be
fine.

If you let the bullet performance dictate the velocity, accuracy,energy and the type of game
you will have many enjoyable hunts.

This criteria is for rifle hunting at longer ranges and should not be compared to other hunting
projectiles because they are designed to perform under different circumstances and cannot
be compared and are for the most part shorter range projectile's, Like the arrow (Kills by hemorrhage and not with energy) and the pistol (Not the ones that use rifle cartriges).

This has all ways been a debate and each person has to live with the outcome if they chose to
extend the range or performance beyond the projectiles limits.

You can kill a deer with a rock ,but would you want to.

J E CUSTOM
 

liltank

Well-Known Member
Joined
Nov 3, 2008
Messages
4,178
Location
Central Pennsylvania
The going number on this sight is 1000ft lbs or 1600fps.

Tank

Just for the record, those numbers you posted are what I use to determine the length of my shot. I know that 2995 fps at 1000 ft of elevation I am able to reach 1200yrds with 1477fps and 1008#'s of energy. This in my humble opinion is sufficient at killing game. However, I have not practiced to that range. I have only had success in hitting a target at 1070yrds but not consistently. Therefore I know that through practice I am only comfortable to shoot to approx. 800yrds because I know that I am capable of hitting my target accurately at that distance.

So to your original question of energy. I use the 1000# or apprx.1600fps rule. If the energy is there, then I will shoot below the prescribed velocity. But as others have discussed I choose the ability to shoot that distance over all else. If I am not comfortable in making the shot, I don't take it. :cool: JE makes a good point in allowing your bullet to dictate the style of hunting that you want to achieve. Hence my original post.

Tank
 

Trending threads

Nightforce has great tracking capabilities, they are rugged, a bunch of elevation, holds zero forever, and reticles are designed for long range shooting. So if you are looking to shoot long distances constantly, then you need a scope that can take the abuse. -- gilmillan1


Culture Of Excellence At Nightforce Optics
By Len Backus

A high level of quality both in production and in service. Read More


Nightforce is such a solid combo of reticle, available elevation, glass that is good enough to shoot at the longest range you can dial. Nightforce has bullet proof construction that can handle the incidental horse rolling or some other rodeo action. -- bigngreen


Nightforce ATACR Scope Review
By Jeff Brozovich

The new NightForce ATACR is for sure a top choice for any long range shooter. Read More


The total package. Nightforce is the best I have used as far as turret feel and solid detents. I have never had one that didn't track right on and always return to zero. Nightforce NXS is the best value for everything I need. -- Broz


Nightforce Velocity 1000 Reticle Review
By Scott Shreve

I think Nightforce knocked it outta the park with this reticle! Read More

NightForce


Top