been so well ingrained into the collective conscience of shooters/hunters by
the gun press that we rarely question the following statements any more (or
slight variations thereof):
1,000 foot-pounds of kinetic energy to reliably kill whitetail deer”
“It takes 1,500 foot-pounds of kinetic energy to reliably
kill elk, moose, etc…..”
isn’t the exact numbers above, it will be something close, within 10%,
usually. Amazingly, this has been
repeated often enough that many states and countries have created laws
regulations which require certain kinetic energy figures to hunt big game
do those numbers mean? Why do we use
them? And are they really relevant to
hunting? My answers are, nothing,
ignorance, and absolutely not.
at a conclusion that will support my arguments, it is first necessary to take a
small detour which might explain how we arrived at the present state.
Roll the clock back approximately to 1870, and consider
the buffalo hunter working for hides and/or meat to feed railway crews. Using cartridges with ballistics that we might consider barely adequate for white-tail deer, they slew animals weighing upwards of a ton, at ranges we would consider completely
irresponsible. And to be sure, there was
wanton waste of game resources…. But they killed a huge number of buffalo, and
recovered the great majority.
bullets were soft cast lead, the powder was black, and the cartridges were
weak. It’s been suggested that the
majority of hunters simply used U.S. Government surplus rifles and ammunition
in the .45-70 and .50-70 calibers. If we
consider how popular surplus military rifles / ammunition have always been,
this is a very valid conclusion. To be
sure, many hunters did use special ‘buffalo rifles’ with various other black
powder cartridges, notably ‘Sharps,’ but these were in reality not a great deal
more powerful than the usual .45-70 & .50-70, and some hunters used lesser
hunter sitting around the campfire would neither know nor care the muzzle
velocity of his gun. Although many
rifles had sights regulated for different distances, the actual business of
hitting targets would have to be worked out by trial and error, due to range
estimation errors by the individual. So muzzle velocity, ballistic coefficients, etc., were just so much
a short time to the dawn of smokeless powder.
This was a revolutionary step forward, but brought with it the following
- Soft lead bullets could not
stand the pressure/velocities. It
would be many decades before dedicated experimenters showed mainstream
hunters that 2,000 or even 2,500fps could be achieved by hard cast bullets
with correct lubes, etc.
- The increased velocities
brought a substantial increase in recoil, if bullet weight were to stay
the same. If a .45-70 kicked hard
with black powder, it could be made to kick really hard with
smokeless. There’s a reason ‘Guide
guns’ are ported!
- Although a hunter could potentially
work up to the recoil of heavier loads, given time, this was not an option
for the armies of the world. They
needed repeating rifles (and ammunition) which were manageable by the
solutions to the above problems were complementary. Small-caliber, metal-jacketed bullets fixed
all problems, as well as increased the amount of ammunition that the soldier
hunters wanted the most modern weapons & ammunition. The increased velocities made hitting at extended
ranges much easier, and less recoil (of smaller,
lighter bullets) was surely appreciated by all!
Jacketed ammo feeds well through repeating rifles designed for it
(ruling out paper-patched bullets for all but dedicated shooters and controlled
environmental conditions). Hunters
suddenly became a lot more interested the difference in
exterior ballistics (muzzle velocity, trajectory, etc.) as these differences
were easily demonstrated on the target range and in the field.
not all hunters rushed to the new technology.
Some had to be dragged kicking and screaming… figuratively if not
literally…. Which is why companies pay lots of money to
problem – small-caliber, full-metal jacket ammunition was very poor for
hunting, in most cases. Although a great
deal of engineering has been put into making FMJ bullets that will either yaw
(turn sideways) at some point in the wound channel, or completely break in two
at the cannelure, this does not make for a
predictable, reliable hunting bullet.
solution was found – the expanding jacketed bullet. With just the correct amount of exposed lead
on the bullet nose, and certain jacket thickness/hardness, we can come up with
a bullet that expands ‘some’ but not ‘too much’ through a certain range of
velocities. If that sounds like a fairly
narrow definition of success, it is!
what it takes to make a jacketed bullet expand.
Simply put, it has to slow down at a very rapid rate
(decelerate). When the front of the
bullet hits something more solid than air (or a paper target), it slows
down. The back end of the bullet, not
having heard the news, tries to keep going, and pass the front. The front of the bullet is badly deformed,
caught between the momentum of the rest of the bullet, and the inertia of the
target (which is normally so much larger than the bullet, that it hardly moves
at all on bullet impact, regardless of the erroneous claims of ‘knockdown
power’ bandied about).
bullet decelerates too much, it may expand to such a great diameter that it
simply cannot penetrate through muscle and bone to damage vital organs (or the
stress can cause it to completely fragment).
If it fails to decelerate enough, it may penetrate completely through
and not expand, without having created enough damage.
that bullet companies go to an amazing effort to ensure that their bullets are
as aerodynamic as possible (ie. have as little
deceleration between the gun and target as possible) … it’s a wonder that they
can be made to perform so well on game!
Only the explanation that the game animal is many times more dense than air explains why this works. The most effective shape for flying through
the air at high velocity is also the least effective shape in wounding
tissue. That statement is vital to
understanding wound ballistics – to create a wound,
there must be resistance to the bullet’s passage.
let’s get back to that. How do you
convince the veteran black-powder hunter that your ‘tiny’ 160 grain .30 cal bullet will in fact be more effective on game than
his traditional 400 grain .45 cal bullet?
Find some attributes of your new product that are superior to his
existing product, even if they don’t really apply to the situation at hand
as mentioned, is one. Less recoil is
another. Turning to science for the
third, we have attribute called ‘kinetic energy’ which
sounds really impressive.
energy (Ke) is a physical characteristic that can be
easily calculated, if we know the bullet weight and velocity. The formula is one half the muzzle velocity
squared, times the mass (not the weight) of the object. This is true for airplanes, cars, rockets,
ships, water stored behind a dam for conversion to electrical power, etc…. it
does not relate to bullets exclusively (note, we divide weight by acceleration
due to gravity to get mass, otherwise Ke on the moon
does not equal Ke on the earth, for identical objects
traveling at identical speeds. Mass
equals weight divided by the acceleration due to gravity, 32 ft per second
squared at sea level on earth).
normal units, foot-pounds (or pound-feet) refer to the amount of energy
released when you drop an object weighing one pound a distance of one
foot. Those in the metric system relate this
kinetic energy incorporates the square of the muzzle velocity, it is biased
toward velocity – which fits in perfectly with the increased muzzle velocities
attainable with smokeless powders!
Coincidence…. I think not.
the ‘hot’ .30-30 Win of 1895 vs. the traditional black powder .45-50 load: 160 grain (original load) bullet, at about
2,000 fps vs. 405 grains, at approx 1,200fps (velocity greatly depending on
barrel length which might be from a short carbine of 15 or 16 inches up to a
full military rifle of 28 or 29 inches; let’s just stick to 1,200fps for the
sake of comparison).
the .30-30 = 1,421 foot-pounds
the .45-70 load = 1,295 foot-pounds
The .30-30 carries the day! And Winchester surely has sold many of them over
the years, millions of rifles and carbines.
debate ignores one teeny, tiny little problem… The .30-30 has to have
that high velocity or it won’t work (because the bullets won’t expand
otherwise). The .30-30 must
decelerate rapidly within animal tissue in order to expand and create a useful
.45 cal bullet does not need to expand.
In fact, for a non-expanding bullet, higher velocity through
tissue makes a better wound channel, because tissue displacement/destruction
decreases when velocity decreases! Prove
it to yourself…. Slap your hand down into water. There is more turbulence the faster your hand
moves, and turbulence through tissue destroys it and creates the wound.
for all bullets that increased speed through tissue creates a larger wound
channel, but we tend to overlook that an expanding bullet will very rapidly
slow down as it penetrates. Deceleration
is not linear, either; drag varies with the cube of velocity and so most of the
velocity is lost within the first few inches of travel, if the bullet expands
rapidly! And a large wound through
shoulder bone/tissue is not nearly as disruptive to the animal’s vascular
system as a smaller wound through soft lung tissue.
it from another perspective. We like to
compare ‘sectional density’ of bullets in different calibers, in order to
compare their relative effectiveness.
Sectional density is the mass of the bullet divided by the
cross-sectional area. So, in theory, our
160 grain .30 cal bullet (sectional density ~ .25) will penetrate just as well
(if not better) than a 350 grain .45 cal bullet (sectional density of ~ .24,
different bullet weight used to make the examples as close as possible). Right?
Wrong! Our expanding .30 cal bullet might increase
in diameter as much as double it’s previous diameter to say .60; yet also the
stress of deforming (er – expanding) the bullet might
cause it to lose as much as 25% of it’s weight.
What’s the sectional density of a .60 cal, 120 grain bullet….. hint…. It’s not real high! 0.048, and consider that the bullet may well
have shed half of it’s velocity penetrating to the
vital organs. Another way of looking at
it – we’re really down to perhaps 400 or 500 foot-pounds of energy that can be
‘delivered’ to the vital organs of the deer.
What???? Yes, it’s true; run the
numbers for 120 grains (the bullet weight we have left) and take a guess at how
much velocity the bullet has left after expanding and penetrating through
shoulder tissue (maybe 1,200fps?) and that’s what you get. Even assuming that deceleration is linear –
which it isn’t – and if the bullet would decelerate from 2,000fps to 0 fps in
10 inches of tissue, the first two inches of tissue would drop bullet velocity
from 2,000fps to 1,600fps, and combined with the decreased mass of the bullet,
we’re down to 682 foot-pounds of ‘energy’.
More likely, it’s several hundred feet per second slower yet, with a
corresponding reduction in Ke. How did I get 10
inches of penetration – from those who would claim perfect bullet performance
is finding the expanded bullet in the skin on the off side, combined with
typical whitetail deer dimensions.
doesn’t seem possible that a considerable amount of energy (read velocity) is
used (lost via deceleration) merely to deform the bullet in it’s first few
inches of travel, place a jacketed bullet in a large bench vise and pound it
with a 4 lb. hammer until it deforms to double diameter. It’s a real eye-opener!
Yet – we
might well look down our noses, at a handgun bullet traveling ‘only’1400 or
1500fps or so, of about .35 cal and the same 160 grain weight, as being
entirely insufficient for deer hunting.
True, if our handgun bullet expands to the same degree, it’s going to
have problems. Yet – if it doesn’t have
to expand, then it doesn’t have to have considerable deceleration on
entry, and will maintain the velocity much longer in tissue. This isn’t theory; ask anyone who hunts with
hard cast bullets in a handgun if they’ve recovered one. I haven’t….. penetration
is measured in feet! If a 160grain hard
cast bullet can penetrate 2 feet of tissue, and decelerates uniformly, it still
has almost all of the original velocity as it travels through lung tissue on a
shoulder shot. Let’s say it’s going
1,300fps (and still has all 160 grains mass, Ke is
now ~600 ft.-lbs) as it enters the chest cavity. Very comparable
velocity as it enters the lung tissue, compared to the rifle bullet after
expansion, if not actually higher! So
why would we consider it less effective?
difference we might draw between the two is the wounding potential. So what you say, my ‘big’ (expanded) .30 will
make a bigger hole through lung tissue than your ‘small’ non-expanding .35,
right? Specifically, the .30 cal bullet
expands into what’s normally a larger round nose bullet profile – the classic
‘mushroom’. Our .35 never changes
shape. A round nose shape does not have
the wounding potential of a flat-nosed shape, because it flows through the
tissue easier. So it has to be larger
than the flat-nosed bullet, to destroy the same amount of tissue! Read that again if it doesn’t make sense… it
is key to understanding bullet performance on
game. The more blunt shape wins….
Always! Try paddling a rowboat with a
square stern backwards, vs. using the pointed or rounded end first.
of the Ke lover….. the
expanding bullet stops in the deer, therefore it delivers more
energy to the vital organs. Well, not likley….. lung tissue is mostly
air, and the bullet probably lost very little velocity crossing the chest
cavity. I would hate to contemplate the
pile of deer lungs that would be necessary to stop even a .30-30 bullet! The off-side ribs and/or shoulder are what
stopped the bullet – again, energy expended on non-vital tissue. Hide is very elastic also, and easily
stretches to ‘catch’ a round-nosed mushroom as the stress of the impact is
distributed over a larger area. The
hard, sharp nose of the cast bullet easily cuts a hole through the hide and
exits (and it probably doesn’t hurt that it’s traveling faster at this point as
bullets ‘deliver’ surprisingly little energy to (vital) lung tissue, if we stop
to calculate the likely deceleration in that soft spongy organ. Both bullets are going to be very effective
on deer, a proven fact. Conclusion: kinetic energy at the muzzle is just a
meaningless number. It has little effect
on terminal performance. Last nail in
the Ke coffin is that it doesn’t scale (why does a
1,000lb. elk only need 50% more Ke than a 100lb.
kinetic energy argument is essentially circular. My fast bullet has a lot of Ke, and I need a lot of Ke to
hunt with, therefore I need a lot of velocity from my bullets. Or, my fast, jacketed expanding bullet is
superior to the slow cast bullet, because it expands (and it only expands
because it is fast in the first place).
.30-30 rifle bullet vs. the .35 cal pistol bullet was deliberately chosen as
these are often considered minimum caliber choices for big-game hunting (by
their proponents, not detractors). Scale
the comparison up to say, the .30-06 vs. the .44 mag…
the .338 Win vs. the .454 Casull or .475 Linebaugh…..
the examples will be very similar, as well as the
results in the game fields!
I’ll admit to using high-speed jacketed rifle bullets. I’ve taken game with them and continue to do
so. I’ve even recommended them – and
help friends load their own for hunting.
But I refuse to buy into the misleading argument that more energy makes
for a more effective load – results personally observed in the game fields
don’t correspond to kinetic energy, momentum, or much else for that matter,
other than hitting in the correct spot.
have it, an explanation of one of the great marketing schemes of the ages,
which continues to this day to mislead hunters, game departments, and our
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