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
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How much Energy to kill a Deer?
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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
MontanaRifleman
Well-Known Member
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...
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...
MontanaRifleman
Well-Known Member
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....
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
liltank
Well-Known Member
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mikebob
Well-Known Member
I go by nothing less than 1400fps and i shoot berger bullets, its worked good for me.
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
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Ballistic Pendulum
MontanaRifleman
Well-Known Member
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.
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.
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justgoto
Well-Known Member
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.
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.
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.
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
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
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.
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
