Authors Note: I originally did this test and
wrote this article back in the early 1970's. While it is still valid, we
could use a newer test. How about some of you? Set something up, take
photos, record all the measurements and send it to us.
Hard Does It Hit?
Most people who shoot for
very long soon begin wondering about the power of their guns. When the
bullet strikes its target how hard does it hit ? What is the effect? Is it
more powerful than...? Every once in a while "discussions" get going as to
which gun/load/caliber "hits the hardest" or words to that effect. The
question is basically the same no matter how it is phrased.
Ammunition companies have
supplied kinetic energy figures with their ballistics data for years. This
is in the form of "foot-pounds" of energy, usually written as "ft. lbs." in
the manuals. And when you read that the .308 has 2460 ft. lbs. of energy at
the muzzle compared to 1350 ft. lbs. of energy for the .44 Magnum sixgun, it
looks like the .308 would be LOTS more effective at killing deer or game
than the .44 would be.
But... as with most things,
there is a problem with the foot-pounds theory of bullet energy. To begin
with, the definition of "foot-pounds" is: "a unit of
energy, equal to the amount of energy required to raise a weight of one
pound a distance of one foot." (Webster's)
Anyone who has ever played around with firearms for very long has
discovered that a gun with "2000 ft. lbs." of muzzle energy will not move
100 pounds sideways 6" let alone lift it a foot!
Here's an experiment for
you to try. Fill a 5 gallon bucket full of sand. Set it on the ground and
shoot it with your rifle that has over a ton of muzzle energy. Let me know
if it moves it all. If the foot-pounds idea were correct, the bucket would
go flying. But it will not. Suspend it on rope 3 to 4 feet long, and shoot
into it with your super-duper belch-fire Magnum and see how far it moves it.
Not much I can tell you right now.
Lest you think I am against
using kinetic energy measurements ("foot-pounds") let me state that it is
useful for comparing certain loads to each other. But I would stick with the
same caliber when making comparisons. Its almost useless when it comes to
other areas and often leads to misconceptions when it come to pitting one
gun/caliber against a different gun/caliber. Such as comparing the .44
Magnum revolver to the .308 rifle. While the rifle is without question more
powerful, when it comes to dropping game the .44 handgun will do the same
job the .308 does, within limits. If you were to use both guns shooting at
the same animals at comparable distances (under 100 yards say) there
usually is not a discernable difference between the effect of either gun on
the animal when hit in basically the same spot. I make that statement based
on my experience shooting animals over the last 35 or so years.
Over 30 years ago I was
sitting around with my Dad and some friends and we were discussing the
subject of hitting power. We decided we would experiment a bit. It gave us
an excuse to shoot! We went out in the yard, nailed an 8 foot 2x4 onto a log
that weighed about 20 pounds and hung it from the clothesline. We shot a few
guns into it and were mildly surprised that none of them moved it very far.
The .300 Winchester Magnum only moved it 6" or so! (all the bullets stopped
in the log so it soaked up all their power) Dad took a 20 ounce claw hammer
and whacked the end of the log as hard as he could and it moved it about 6".
So we concluded the .300 Magnum hit about as hard as a whack with a 20 oz.
claw hammer. Now that is nothing to make light of. But it isn't nearly a ton
and half as the kinetic energy figures would lead us to think.
I decided to get serious
about this - this was in the ancient days before personal chronographs - so
we built a frame from which we hung a 48-pound mesquite log. It was hung on
a 6-foot long arm and had a tape fixed to it to accurately measure the
movement of the log. The log stopped all bullets fired into it. We figured
out what loads we were going to shoot beforehand and had bullets of equal
weight on the log. When one was fired into the log, one was removed keeping
the weight of the log the same. It probably was unnecessary, but that is
what we did. What we found was that some handguns hit just as hard as
rifles. This confirmed observations on game in the field.
If you watch the Anite
Productions video DEADLY EFFECTS, the producer of the video takes a point
blank shot on a vest with .308 Nato ammo .. WHILE BALANCING HIMSELF ON ONE
LEG! Just to prove that the actual hitting power is not all that hard. It
don't knock him down. He actually does it twice on the video just to make
I know someone will bring
up the fact that the energy is "dissipated" over time and distance, or other
such arguments. Think about it. The bullet STOPPED on the vest. All energy
was expended. The .308 has over 3000 ft. lbs. of muzzle energy. Over a ton
and half. Even if the bullet "lost" a ton of energy magically, somehow
dissipated into the vest, it still should have enough power to knock over a
175 pound man balancing on one leg!
In our tests shooting the log,
the log absorbed all the energy the bullet had, even if it did take a few
hundredths of a second. Don't try to argue that X amount of energy gets
turned into heat, while X amount of energy moves wood particles or peels
the jacket back or whatever. It's all inside the log and happens in an
incredibly short space of time. Even if 3/4 of ton of that hypothetical
ton of muzzle energy was siphoned off by the bullet coming apart in the
log, 1/4 ton of energy should still move it more than an inch or two!
We did not
actually prove anything. However it was fun to do. What we were measuring is
called "Momentum Energy" by those who are better at math than I. Momentum is the
amount of "push" a moving object has. Obviously the weight of the moving
object is a big factor, influencing the results more than velocity. With kinetic
energy figures velocity is the big factor which influences the
Above - a much younger
Jim Taylor firing an 1886 Winchester 45-70 into the log.
results. There are other methods of
figuring hitting power, such as the "Taylor Knock Out" theory. It favors
caliber. All such theories have their drawbacks and limitations. They are part
of the quest to find a way to put down on paper what we observe in the field.
And... all the different ways
of measuring a bullet's power are interesting. The best way though is to get out
in the field and do it up close and personal.
Recorded Movements of
a 48-pound pendulum on a 6 foot arm.
(All shots were fired at 15 feet from muzzle
to the pendulum)
125 gr. FMJ
Magnum 2 1/2"
Rem. 140 gr. JHP
Super-Vel 110 gr. JHP
Super-X 158 gr. lead
Super-Vel 110 gr. JHP
Special Charter Arms
Rem 246 gr. lead
ACP Model 1911-A1
230 gr. Hardball
|45 Colt 7 1/2"
||WW 255 gr. lead
||300 gr. handload
|44 Magnum 7 1/2"
||Rem. 240 gr. JSP
Super-Vel 180 gr. JHP
||Rem. 170 gr. JSP
||WW 150 gr. JSP