How Hard Does It Hit?

by Jim Taylor

Most people who shoot for very long soon begin wondering about the power of their guns.  How hard does it hit when the bullet strikes it's target?  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 belchfire Magnum and see how far it moves it.  Not much I can tell you right now.

Lest you think I am a total humbug on "foot-pounds" let me say that it is useful for comparing certain loads to each other. But I would stick with the same caliber when making comparisons.  It is totally 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 great   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 25 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 our deductive reasoning 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 ain'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 - and 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.   Observations on game in field confirmed our findings also.

I don't know that we proved anything.  However it was fun to do.  What we were actually 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 object is a big factor, influencing the results more than velocity.  With kinetic energy figures,   velocity is the big factor which influences the results. There is another system for figuring hitting power called the "Taylor Knock Out" theory.  For more on that read John Linebaugh's article on Handgun Hunting.  

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.  For the times when you can't get out, here are the results of our tests:

RECORDED MOVEMENTS OF A 48-POUND PENDULUM ON A 6-FOOT ARM

(all shots were fired at 15 feet from muzzle to the pendulum)

  The big winner of the day was the old .45-70 cartridge.  I shot some original UMC blackpowder loads with the 550 gr. bullet.   These pushed the log 5 1/16"!  Of course, as I stated above, bullet weight is a big factor in this kind of testing.  What does it prove?  Not much.   A hit in the right place with a decent load will do the job.  A miss with a Magnum is still a miss.  Nothing can replace expertise.  However, on those long winter evenings when you are sitting around with friends and the subject of which gun is more powerful comes up,  here's a new way to start an argument - or end it.