Range Report A bullet CANNOT knock someone/thing over can it?

#51
Re: A bullet CANNOT knock someone/thing over can it?

In the end, it is force that pushes/drops something and this can be calculated using either momentum or energy. Both are conserved during a collision. The kicker with energy is that it is TOTAL energy that is always conserved. Energy can change forms during the collision. Kinetic energy is not always conserved.

F=M*A
A=F/M

To determine how much the object gets "pushed", you need to determine it's acceleration. This is a function of its mass and how much force it experiences.

Fo=Fb (Force object experiences = Force bullet delivers)
Ao=Fb/Mo (Acceleration of object hit = Force bullet delivers / Mass of object getting hit)
Ao=Mb*Ab/Mo (Acceleration of object hit = Mass of bullet * Acceleration (deceleration) of bullet / Mass of object getting hit)

So, for a given impact force, the larger the object getting hit is, the less it will accelerate (all else being equal). The mass of the object is easy, the force the bullet delivers to it is not so easy. This is what needs to be calculated from the momentum equations. It is highly dependant on the bullet's terminal performance. How the bullet decelerate (negative acceleration) determines how much force the object experiences (i.e. energy gets transfered). This is the idea behind designing cars that crumple during an accident. The deformation of the body results is a smaller deceleration and thus, less force on the occupants of the vehicle.

In the case of your 50 BMG hitting the deer above, you would use the equation for elastic collision since the bullet does not stay in the deer. If you make some assumtions about the velocity of the bullet after the impact, you can calculate bullet deceleration based on the width of the deer.

A(avg) = (V2-V1)/dt

If the bullet gets stuck in the animal (varmint bullet), you need to use the equation for inelastic collision. You need to guess at how much it penetrates and how long it takes for its velocity and the objects velocity to become the same. Then you can determine its deceleration.

A(avg) = (Vf-Vb(i))/dt

The problem with doing this whole exercise using simple momentum equations is that it it requires you to make all kinds of assumptions and predictions about the terminal performance of the bullet. You're simplifying something that is in reality, very complex. A really detailed computer model that takes all things into account could probably predict it more reliably, but that isn't what the OP is looking for. If you want to take the quick and dirty practical approach, then do what I originally suggested: take known results on an animal/object of a given size, scale the weight and velocity of the second bullet based on the energy/bodyweight ratio. And most importantly; compare similar bullets.

*The bullet that passes through an object transfers less energy than one that stays in it (bullets of equal mass and velocity)
*The bullet that penetrates more, experiences a lower deceleration, and transfers less energy than the one that stops in the object sooner (bullets of equal mass and velocity)

A 750 gr. AMAX is a solid that doesn't expand; it doesn't transfer energy as efficiently as a varmint bullet. A frangible bullet is probably closer.

If you make a general statement that a bullet cannot knock someone/thing over, as the title says, that is incorrect. It is dependant on the size of the person/animal/object, the energy of the bullet and how well that energy gets transferred. It can also depend on where the object's center of mass is if the force is small relative to the object's mass. There isn't a black and white rule that can be applied for any bullet hitting any object.

If you site specific examples; size of person/animal/object along with weight, velocity and type of bullet, then you can make claims as to how much that person/animal/object will or will not be moved by the impact. The 308 does not make a moose budge, but it does send a gopher flying. Some size of animal in between them will simply get knocked down.
 
#52
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TiroFijo</div><div class="ubbcode-body">Sandwarrior, it seems you miss the "small detail" that the steel targets you shoot are about 1/30 of your weight...
wink.gif

</div></div>

Don't forget that steel cannot absorb shock, it reflects from it - the human body absorbs the shock...

If Mythbusters could not knock over a pig, I sincerely doubt that a 400 pound terminator could get blown 6 feet back by a shotgun slug LOL
 
#53
Re: A bullet CANNOT knock someone/thing over can it?

Momentum is always conserved when the bullet strikes the target, no matter the process. This is just about the only law of physics which has survived over 300 years.

If the bullet stops in the target all of its momentum is transferred to the target. If it passes through, then not all of the bullet's momentum is transferred, but the total momentum of the bullet and target equals the bullets initial momentum. If the bullet bounces back from the target, then the target can acquire more momentum than the bullet had originally, balanced by the negative momentum of the bullet going backward. All this also conserves energy.

Taking the case that the bullet stops in the target and the target is the weight of a human (as the original question specified) lets put in some numbers. Momentum conservation says:

m(bullet)*v(bullet)=m(target)*v(target)

suppose
m(bullet) = 150 grains = .02 lb
v(bullet) = 3000 fps
m(target) = 100 lbs

(Mass is not quite the same thing as weight, but it goes out in the ratio so skip this detail.)

v(target) = 3000fps * .02 lb/100lb = .6 fps

Note that a 100lb shooter also will recoil at this same speed.

You can decide if pushing a person 7 inches over a 1 second time interval would knock him down. It didn't knock down the shooter, probably. Maybe if the person is drunk, but he won't fall far. The person falls down dead, because most of the bullets energy was dissipated destroying his tissues, his blood pressure drops to nothing, and he passes out. But he isn't knocked violently backward like in the movies.

Sure one can knock over a 10 lb metal target - especially if the bullet bounces back - but that wasn't the question. As pistol shooters know, even those metal plates can stubbornly resist falling over.
 
#56
Re: A bullet CANNOT knock someone/thing over can it?

I believe shock accounts for many of the instances of animate objects being "knocked over". There is also the issue of balance. If I stand a book on end, it doesn't take much of a tap to send it over. As bipeds we don't have a great deal of stability without muscular control.

I think "fell over" would be a better description. The bullet simply provides enough force to push the body out of alignment and then gravity takes over.

Also remember that when you are talking about Level IV body armor, the bullet is expending ALL of it's energy immediately in the face of the armor. That is a hell of a hit versus the bullet being slowed through 10-12" of meat.

However, I agree. I don't want to be on the receiving end EVER.
 
#58
Re: A bullet CANNOT knock someone/thing over can it?

Again,

I found it pretty amazing that the dumbasses in the video noted that a baseball (5 oz. or .3125 lb.) moving at 60-70 mph moved the dummy just as much as a 750 gr. or .107 lb. .50 cal projectile moving at 1638 mph. Don't you think there is a little inequity there??? Sure looks like it to me. Maybe all you doubters out there went to school somewhere else where the math is better....

I understand conservation of momentum. The first thing you always get shown when that is being demonstrated is the rack of hanging balls and how when you swing the first one the last one swings up then comes back down and hits the stack and the first one swings up. Have you seen the one where they took a whole bunch of different sized balls centered them up and the same thing happened? Maybe because there was still a 100% transfer of momentum is why it works. Size doesn't matter in that case, point of impact does. Whaddya know
crazy.gif
, maybe that has something to do with it.

And you guys quoting the shootee falling down would mean the shooter would have to fall down are forgetting the MOST IMPORTANT THING....HE (shooter) - - HAS - - A - - GUUUUNNN. You know a fire arm. That takes up recoil and transfers recoil to the body in a way that it can be controlled. ....Or you wouldn't be able aim it, let alone hang on to the cartridge and fire it from your bare hand. We talk about them here all the time. OH, did us math geniuses forget that factor?? The guy taking the bullet isn't catching it with a gun. Not sure if you noticed that or not. So the shooter isn't going to fall backwards unless the recoil presented from his gun is big enough to kick his ass. But, it has no bearing on what the guy standing downrange is about to receive

I'll stick to my original analogy in case you still don't understand. A bullet is a weight. When fired from a gun it moves so damn fast you can't usually see it. But it is a weight, and it is now moving through the air. When it hits a solid object it will impart {energy, momentum, force, voodoo shit, PFM...something} And the target, depending on how hard headed it is, is going to absorb that {...something}. And it is going to be moved. Depending on it's thickness (your brain would move a lot) it's balance, how the bullet hits it, how the bullet reacts after it hits it, is going to be how much it moves. But it moves, no matter how much or how little.
 
#61
Re: A bullet CANNOT knock someone/thing over can it?

Last person I saw shot was hit by a .380acp ball round. He fell <span style="font-style: italic">forward</span> after being hit in an artery directly above his heart.

Then again, I caught a ricochet from a .38 LSWC fired from a 2" snub. It hit my ankle, and though it didn't knock me over, it most certainly disrupted my balance - enough that I leaned <span style="font-style: italic">forward</span> to compensate.

Josh <><
 
#66
Re: A bullet CANNOT knock someone/thing over can it?

I guess I'd argue that a bullet absolutely can knock someone over. The argument that if a bullet could knock someone over, then the shooter would fall over as well is somewhat flawed. You shouldn't be looking at conservation of momentum without considering the impulse that each party experiences. http://en.wikipedia.org/wiki/Impulse There is a reason people put squishy pads on the buts of their rifles, it reduces the peak force they experience by extending the time over which that force is exerted. The area under the force vs time graph is the same, preserving momentum, but on the receiving end you have a very different system with different peak forces. Also, a person is inherently unstable when they are standing, they are continually making adjustments to stay standing (ever see someone pass out or faint and not fall over?) so all you need to do to knock them over is to upset that balancing act. I have no idea what the equations to describe that might be, but at the very least it would depend on shot location relative to center of mass, because that would induce angular momentum which must also be conserved. It's much easier to knock someone over if you hit them in the head or feet instead of the stomach.

I'll also throw out that when theory and reality don't match up, it's generally easier to get a new theory than a new reality.
 
#67
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">So. Getting back to the original question; what have we determined here?

Premise stands?

Premise sucks?

What? </div></div>

The premise sucks because it doesn't define what it means to knock over the target. If you tie together the feet of the shooter and the target, both will be knocked over, just not very fast. I can push someone over with one finger, if they are not allowed to move. If they have a supported position, or time to take a half step, they won't be knocked over. In any case it is not a violent motion.
 
#69
Re: A bullet CANNOT knock someone/thing over can it?

I thought a bullet could certainly knock somebody down. I actually asked my GF to ask her professor apparently this subject already came up in class. The class is physics 121 the professor is Brian Jones the school is Colorado State University. Apparently Mr. Jones is highly thought of professor. Rated one of People magazines top 200 College Professors. Anyway back on topic. So according to Mr. Jones the formula for this collision would be

Vf=m bullet/(m bullet + m victim) x v bullet

or
Final Velocity= Mass of the bullet/(Mass of the bullet + mass of victim) x Velocity of bullet.

So using an actual profile of an m40a1 with a muzzle velocity 813.8m/s, a bullet mass of 11.34grams (175 grain M118LR cartridge) and a target mass of 72.4kilos(160lb person) and a target velocity of 0 m/s (standing still).

The equation works out to the target(weighing 72.4kilos) traveling backward at a rate of 1.2m/s which isn't fast enough to be knocked down. I guess it would be equivalent to somebody trying to push you back. 1.2m/s is actually quite slow. Apparently no matter how fast the bullet is traveling its the mass that counts. The mass of a human is far greater than the mass of the bullet. Say another human being traveling 813m/s hit another human of the same mass it would obviously knock the victim down. In fact another human traveling at a much slower speed would knock the victim down (think of a football hit or an open-ice hockey check). I will say this though. I suppose that somebody wearing body armor, i.e. esapi plates, would experience much more "knockdown" force because the bullet isn't simply passing through them but actually being absorbed by them. Think of a broadhead passing through a deer or elk as opposed to hitting it with a car. Hope this helps.
 
#70
Re: A bullet CANNOT knock someone/thing over can i

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Surffshr</div><div class="ubbcode-body">I can knock over an aspirin at 300m </div></div>

You're comment is actually 100% correct and pretty much sums up this entire argument. Good job.
 
#73
Re: A bullet CANNOT knock someone/thing over can i

And this is with a bullet that transfer ALL of its momentum to the target (even more, the fraction of bullet spall that bounces back increases it).

With a bullet that penetrates through the target only a fraction of the momentum is transfered.
 
#74
Re: A bullet CANNOT knock someone/thing over can i

Let me take my fist and punch your dumb ass in the face. And when it knocks you over, because it will, I've done it before, tell me that that was more/less force than what a bullet applies to a body when it hits it??
 
#76
Re: A bullet CANNOT knock someone/thing over can i

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body">Let me take my fist and punch your dumb ass in the face. And when it knocks you over, because it will, I've done it before, tell me that that was more/less force than what a bullet applies to a body when it hits it??</div></div>

"Dumb ass" you may think highly of yourself, internet macho, but if you punch as good as you understand physics, no one has to worry about it
laugh.gif
 
#77
Re: A bullet CANNOT knock someone/thing over can i

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">^^
they've got pills for that now you know....</div></div>

And I don't bother trying to get them or take them.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TiroFijo</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body">Let me take my fist and punch your dumb ass in the face. And when it knocks you over, because it will, I've done it before, tell me that that was more/less force than what a bullet applies to a body when it hits it??</div></div>

"Dumb ass" you may think highly of yourself, internet macho, but if you punch as good as you understand physics, no one has to worry about it
laugh.gif
</div></div>

Well, I've been there, and I've done that. If you think a punch exerts more energy than a bullet maybe we should throw down our arms because they don't do anything more than what I could push you with my finger.

Do you get the point? Is a punch with a fist more or less powerful than a bullet hitting you? If you don't get that analogy you never will. But, I noticed you felt awfully threatened by the post. Like I'd really waste the time and money to go to South America to punch you...
crazy.gif
That would mean you didn't even read the intent of the post. Line two in this paragraph clearly states the intent of that statement. Read, re-read, think.

I understand physics quite well. I think you and you're internet wannabe's have tried to show in simple physics, without factoring in a bunch of real variables how a bullet can knock an animal or a human being over. Factors such as leverage [height of impact vs. fulcrum(s)], and how much of the body (mass) is actually being moved, and at what speed the incident happens (impulse).

The bottom line to this is it really doesn't matter. It has no bearing on anything. It's just another dumb question. Could it happen? Yes. Does it always? No. Does it happen like in the movies? Not hardly ever.

Oh, and BTW, I've never seen any ballistic vest makers standing around in shorts shooting each other with .308's and .44 mags. Ever watch Monty Python and the Flying Circus? Insurance would have a field day with that and they'd be out of business pretty quickly. Blanks were my thought.
 
#79
Re: A bullet CANNOT knock someone/thing over can it?

Fitty cal can knock you over.

Or perhaps more correctly, cause body mass to experience such a pressure increase that the skin / flesh literally explodes, and you fall down. Or go flying.

There's Afghan video evidence of this.... http://www.youtube.com/watch?v=TOZoYIoyjuM ENJOY!


But the mass of a bullet, even a 750 grain bullet, will NOT knock down a 150 + lb body.



 
#81
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">Those are old videos of guys shooting marmots. Been around forever.
</div></div>

One was a human arm. Another was much larger than a marmot.

I'm aware of its longevity.

But it shows the pressure effects of very large caliber bullets.

Check this (reported) vid of 50 cal. vs. ballistic gelatin...
http://www.youtube.com/watch?v=xYSGuiko6...PL&index=11
 
#82
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: garandman</div><div class="ubbcode-body">Fitty cal can knock you over.

Or perhaps more correctly, cause body mass to experience such a pressure increase that the skin / flesh literally explodes, and you fall down. Or go flying.

There's Afghan video evidence of this.... http://www.youtube.com/watch?v=TOZoYIoyjuM ENJOY!


But the mass of a bullet, even a 750 grain bullet, will NOT knock down a 150 + lb body.



</div></div>

Mythbusters showed it did....whaddya think about that? Go back and watch that video in the third or fourth post. 'course if you watch it, you'll see that a 50 cal only has about the same power as a baseball.....
 
#83
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
sandwarrior


Mythbusters showed it did....whaddya think about that? Go back and watch that video in the third or fourth post. 'course if you watch it, you'll see that a 50 cal only has about the same power as a baseball..... </div></div>

Cool episode.

As mentioned before, the physics, inertial mass, and force of the 50 cal bullet will be the same on the sending and receiving end.

A 50 cal rifle fired offhand MAY knock down a few shooters.

But the pressure of a 50 cal entering a "closed body mass" will cause it in many cases to literally explode.

That's another form of knockdown power.

 
#84
Re: A bullet CANNOT knock someone/thing over can it?

Let's see....I got the opportunity to shoot about a 30 lb. dog with a .30-30 yesterday from about 10 yards away. I was using a 160 grain flex-tip bullet which fires out of my Winchester at about 2400 fps which is about 2046 ft. pounds of energy. The dog definitely received the full energy from the round since it was only about 30 feet from the muzzle.

I shot the animal with it standing perfectly broadside to me, aimed directly at the left shoulder area. When the round hit, the dog simply dropped to it's knees and layed right down on it's stomach before rolling over. The round never exited the animal so all of the energy of the round dumped into it.

The animal didn't do anything spectacular.....just simply dropped down. I think its' the animals physical reaction to being shot that makes the illusion of being "knocked-down".....not the actual power of the bullet.
 
#85
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RussW1911 ®</div><div class="ubbcode-body">If I had the technology to do it, I would post multiple Deer, Antelope and Elk that were takin' with a 338 RUM from 78 yards to 700+ yards and not one of them did the back flip that some of you guys like to pound your chest about and tell stories to the unknowing. Keep your stories for the bars and your girlfriends and quit trying to bull shit everyone.

I shoot high shoulder and not one of these animals did the extreme acrobatics that your talking of.... was the 338 RUM not good enough?</div></div>

I didn't say back flips and acrobatics. I said,..."knocked over." I also didn't say slammed to the ground.

The whole point here is that, in the simplest physics I can explain it to you, A bullet is a weight, moving at a speed. It imparts energy when it hits something. It even imparts energy to the air it moves though (just in case you didn't know air is a substance and has a weight and resistance when something moves through it.)

How much energy it imparts depends on a lot of things. Shape, construction and velocity of the bullet. And, consistency of the target. Why do you think steel silhouettes fall down when they are hit? Because they want to? No, it's because the bullet imparted energy to it. Some animals don't absorb the energy some do. The ones that absorbed the energy fell down. The ones that didn't either went down or took off running.

It's that simple. And I still don't give a damn what those ass-hats on mythbusters say. </div></div>That about sums it up. Simple physycs. It doesn't have to be complicated. Didn't Col. Cooper design the .45 for the explicit purpose of stopping a man in his tracks?
 
#86
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mgd45</div><div class="ubbcode-body">Let's see....I got the opportunity to shoot about a 30 lb. dog with a .30-30 yesterday from about 10 yards away. I was using a 160 grain flex-tip bullet which fires out of my Winchester at about 2400 fps which is about 2046 ft. pounds of energy. The dog definitely received the full energy from the round since it was only about 30 feet from the muzzle.

I shot the animal with it standing perfectly broadside to me, aimed directly at the left shoulder area. When the round hit, the dog simply dropped to it's knees and layed right down on it's stomach before rolling over. The round never exited the animal so all of the energy of the round dumped into it.

The animal didn't do anything spectacular.....just simply dropped down. I think its' the animals physical reaction to being shot that makes the illusion of being "knocked-down".....not the actual power of the bullet. </div></div>The energy dissipated instead of transferred. What do you think would have happened if you shot a steel bullet at a 30# steel plate at that distance? (honest question, not trying to "poke" at you)
Even lead bullets on steel plates dissipate energy. The more destruction done, the more energy dissipated, and not transferred. Transferred energy is what will knock something down. At a close distance, the bullet may just completely disintegrate <span style="font-style: italic">rapidly</span> dissipating the energy and not transferring it to the target. More distance, and the bullet may have held it's shape better and transferred more energy and in fact, knocked that dog off it's feet. OR- a better designed bullet to hold it's shape at that distance and made to <span style="font-style: italic">transfer</span> energy and not dissipate it.

IMO there are just too many variables involved in this to really make a general statement on weather or not a bullet can or will knock something over.
 
#88
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mgd45</div><div class="ubbcode-body">Let's see....I got the opportunity to shoot about a 30 lb. dog with a .30-30 yesterday from about 10 yards away. I was using a 160 grain flex-tip bullet which fires out of my Winchester at about 2400 fps which is about 2046 ft. pounds of energy. The dog definitely received the full energy from the round since it was only about 30 feet from the muzzle.

I shot the animal with it standing perfectly broadside to me, aimed directly at the left shoulder area. When the round hit, the dog simply dropped to it's knees and layed right down on it's stomach before rolling over. The round never exited the animal so all of the energy of the round dumped into it.

The animal didn't do anything spectacular.....just simply dropped down. I think its' the animals physical reaction to being shot that makes the illusion of being "knocked-down".....not the actual power of the bullet. </div></div>The energy dissipated instead of transferred. What do you think would have happened if you shot a steel bullet at a 30# steel plate at that distance? (honest question, not trying to "poke" at you)
Even lead bullets on steel plates dissipate energy. The more destruction done, the more energy dissipated, and not transferred. Transferred energy is what will knock something down. At a close distance, the bullet may just completely disintegrate <span style="font-style: italic">rapidly</span> dissipating the energy and not transferring it to the target. More distance, and the bullet may have held it's shape better and transferred more energy and in fact, knocked that dog off it's feet. OR- a better designed bullet to hold it's shape at that distance and made to <span style="font-style: italic">transfer</span> energy and not dissipate it.

IMO there are just too many variables involved in this to really make a general statement on weather or not a bullet can or will knock something over. </div></div>

I don't know what you mean by dissipate, but I suspect that you don't understand physics at all.

The law of conservation of energy makes it impossible for energy to just disappear.
 
#90
Re: A bullet CANNOT knock someone/thing over can it?

I suspect you don't understand the english language...dissipate isn't a real difficult word to understand. No one suggested that energy "disappeaars". Your reading comprehension is as lacking.<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mgd45</div><div class="ubbcode-body">Let's see....I got the opportunity to shoot about a 30 lb. dog with a .30-30 yesterday from about 10 yards away. I was using a 160 grain flex-tip bullet which fires out of my Winchester at about 2400 fps which is about 2046 ft. pounds of energy. The dog definitely received the full energy from the round since it was only about 30 feet from the muzzle.

I shot the animal with it standing perfectly broadside to me, aimed directly at the left shoulder area. When the round hit, the dog simply dropped to it's knees and layed right down on it's stomach before rolling over. The round never exited the animal so all of the energy of the round dumped into it.

The animal didn't do anything spectacular.....just simply dropped down. I think its' the animals physical reaction to being shot that makes the illusion of being "knocked-down".....not the actual power of the bullet. </div></div>The energy dissipated instead of transferred. What do you think would have happened if you shot a steel bullet at a 30# steel plate at that distance? (honest question, not trying to "poke" at you)
Even lead bullets on steel plates dissipate energy. The more destruction done, the more energy dissipated, and not transferred. Transferred energy is what will knock something down. At a close distance, the bullet may just completely disintegrate <span style="font-style: italic">rapidly</span> dissipating the energy and not transferring it to the target. More distance, and the bullet may have held it's shape better and transferred more energy and in fact, knocked that dog off it's feet. OR- a better designed bullet to hold it's shape at that distance and made to <span style="font-style: italic">transfer</span> energy and not dissipate it.

IMO there are just too many variables involved in this to really make a general statement on weather or not a bullet can or will knock something over. </div></div>

I don't know what you mean by dissipate, but I suspect that you don't understand physics at all.

The law of conservation of energy makes it impossible for energy to just disappear. </div></div>
 
#91
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body">I suspect you don't understand the english language...dissipate isn't a real difficult word to understand. No one suggested that energy "disappeaars". Your reading comprehension is as lacking.<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mgd45</div><div class="ubbcode-body">Let's see....I got the opportunity to shoot about a 30 lb. dog with a .30-30 yesterday from about 10 yards away. I was using a 160 grain flex-tip bullet which fires out of my Winchester at about 2400 fps which is about 2046 ft. pounds of energy. The dog definitely received the full energy from the round since it was only about 30 feet from the muzzle.

I shot the animal with it standing perfectly broadside to me, aimed directly at the left shoulder area. When the round hit, the dog simply dropped to it's knees and layed right down on it's stomach before rolling over. The round never exited the animal so all of the energy of the round dumped into it.

The animal didn't do anything spectacular.....just simply dropped down. I think its' the animals physical reaction to being shot that makes the illusion of being "knocked-down".....not the actual power of the bullet. </div></div>The energy dissipated instead of transferred. What do you think would have happened if you shot a steel bullet at a 30# steel plate at that distance? (honest question, not trying to "poke" at you)
Even lead bullets on steel plates dissipate energy. The more destruction done, the more energy dissipated, and not transferred. Transferred energy is what will knock something down. At a close distance, the bullet may just completely disintegrate <span style="font-style: italic">rapidly</span> dissipating the energy and not transferring it to the target. More distance, and the bullet may have held it's shape better and transferred more energy and in fact, knocked that dog off it's feet. OR- a better designed bullet to hold it's shape at that distance and made to <span style="font-style: italic">transfer</span> energy and not dissipate it.

IMO there are just too many variables involved in this to really make a general statement on weather or not a bullet can or will knock something over. </div></div>

I don't know what you mean by dissipate, but I suspect that you don't understand physics at all.

The law of conservation of energy makes it impossible for energy to just disappear. </div></div> </div></div>

Let's leave off the insults and stick to the science. You're the one suggesting something that is impossible, given the modern laws of motion and energy.
 
#92
Re: A bullet CANNOT knock someone/thing over can it?

a steel bullet will be one less accurate to shoot because the rifling of the barrel would not hold it like it would lead, and it would ruin your rifling, and two since there would not be as much expansion on a steel bullet it would go in and out and alot of the energy would not transfer to you target. In lawenforcement I like to use the Hornady TAP 75 gr. rounds in my AR because the bullet fragments on impact and will transfer all of its energy inside of my target and not beyond.
 
#93
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Let's leave off the insults and stick to the science. You're the one suggesting something that is impossible, given the modern laws of motion and energy.</div></div>Insinuating I know nothing about physics is insulting, given you know nothing about me. "Don't start no shit, there won't be no shit..." (and that's a quote before you criticize my grammer, there, teach...)
What did I suggest that was impossible? For energy do dissipate?
 
#94
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Pollard</div><div class="ubbcode-body">a steel bullet will be one less accurate to shoot because the rifling of the barrel would not hold it like it would lead, and it would ruin your rifling, and two since there would not be as much expansion on a steel bullet it would go in and out and alot of the energy would not transfer to you target. In lawenforcement I like to use the Hornady TAP 75 gr. rounds in my AR because the bullet fragments on impact and will transfer all of its energy inside of my target and not beyond. </div></div>My example of a steel bullet was against a steel plate, not a body, and what it does the the barrel is a moot point...this is about energy. A bullet that fragments does a lousy job of transferring energy. It uses most of it's energy in it's destruction and fragmentation, transferring very little of that energy into the target. This is why I mentioned a steel bullet against a steel plate. Steel will retaion it's shape better than lead or copper and in doing so, it will <span style="font-style: italic">transfer</span> more energy to the target (as long as it doesn't pass through). It also converts a lot of that energy into heat through friction. A lead bullet that fragments, needs energy to propel each one of those little fragments. The more of those little fragments that are created, the more energy is distributed or "dissipated", and the less is transferred. And again, there is conversion of energy into heat through friction.

If a bullet that has 2000lbs/ft of energy hits an object weighing 200lbs, what do you think is going to happen? IF, and this is the big if...the bullet could retain 100% of it's shape, and there was zero penetration of the target, where would all that energy go? Of course, this condition doesn't exist, so the next step is to assume that the closer to that scenario you stay, the more chance you have of the bullet moving or knocking down the target. I don't think that something high velocity with a high fragmentation and penetration is going to have the "knockdown" power that something more slow moving which will retain it's shape is going to have, given both have equal energy. The first may be more lethal, but not transfer as much energy.
 
#95
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Let's leave off the insults and stick to the science. You're the one suggesting something that is impossible, given the modern laws of motion and energy.</div></div>Insinuating I know nothing about physics is insulting, given you know nothing about me. "Don't start no shit, there won't be no shit..." (and that's a quote before you criticize my grammer, there, teach...)
What did I suggest that was impossible? For energy do dissipate? </div></div>

I never said anything about you <span style="font-style: italic">not knowing</span>. I merely pointed out that rather than rather than engage in substantive debate, you decided to attack me rather than the data.
 
#96
Re: A bullet CANNOT knock someone/thing over can it?

"Steelcomp",

Wouldn't all the little lead & copper fragments from the bullet still transfer it's energy into the body of the animal? The way I was looking at it, was even if the energy of the round dissipated into smalled fragments, those fragments now have energy & they are stopped by the animals skin, muscles, tendons, etc...

So since the round didn't leave the animal, then all the energy has to dump in the animal, even if that energy is transferred by one big bullet or a bunch a smaller ones...? Am I missing something in my assessment?
 
#97
Re: A bullet CANNOT knock someone/thing over can it?

almost the same amount --- minus the amount needed to "break up" the bullet, and the heat generated in the process.
 
#98
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steelcomp</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Let's leave off the insults and stick to the science. You're the one suggesting something that is impossible, given the modern laws of motion and energy.</div></div>Insinuating I know nothing about physics is insulting, given you know nothing about me. "Don't start no shit, there won't be no shit..." (and that's a quote before you criticize my grammer, there, teach...)
<span style="color: #FF0000">What did I suggest that was impossible? For energy do dissipate?</span> </div></div>

I never said anything about you <span style="font-style: italic">not knowing</span>. I merely pointed out that rather than rather than engage in substantive debate, you decided to attack me rather than the data. </div></div>This is "substantive debate" to you? Where's your "reference to the data"? You should practice what you preach, my frieind. Relax, have some fun...join the discussion. It's Oooohhh-Kaaayyyy.
wink.gif
 
#99
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mgd45</div><div class="ubbcode-body"> "Steelcomp",

Wouldn't all the little lead & copper fragments from the bullet still transfer it's energy into the body of the animal? The way I was looking at it, was even if the energy of the round dissipated into smalled fragments, those fragments now have energy & they are stopped by the animals skin, muscles, tendons, etc...

So since the round didn't leave the animal, then all the energy has to dump in the animal, even if that energy is transferred by one big bullet or a bunch a smaller ones...? Am I missing something in my assessment? </div></div>The way I imagine it, (and mind you, I'm definitely an armchair expert here, ie: I really know nothing) is each of those fragments is put into motion, which requires energy. That energy is being transferred from (taken away from) the energy stored in the moving bullet, and while yes, I agree that there is some energy transferred from the small particles into the mass of the object, a tremendous amount of energy is "spent" breaking up that bullet and putting into motion those small fragments. The more of those fragments, the more energy is taken from the original bullet. If the bullet only split into two pieces, each would retain more energy. Divide that into four, more energy required, divide that into 16, yet more energy required, etc.
Someone earlier eluded to a car's ability to absorb energy through destructive panels rather than transfer it to the driver. In F1 racing, cars are designed to totally disintegrate around a driver under high impact situations, like hitting a wall at 200mph, and allowing the driver- who is inches from the impact- to literally walk away. In the 50's, a race car would go bouncing and bounding down the race track and maybe lose a wheel, while all that time the driver was literally being beat to death because he was experiencing all the energy being transferred throughout the car. If a bullet can retain it's shape, it, in similar fashion, retains it's energy. I think in answer to this thread, a target being knocked down has as much to do with the target as it does the bullet.
BTW...the only thing that stops your car is converting the car's kinetic energy to heat through the friction in your breaks. I suspect something similar is happening with the destruction of a bullet. Something to ponder.
I'm only voicing an uneducated opinion here.
 
#100
Re: A bullet CANNOT knock someone/thing over can it?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shooter2</div><div class="ubbcode-body">almost the same amount --- minus the amount needed to "break up" the bullet, and the heat generated in the process. </div></div>Yes, and also the direction of the energy is no longer linear, but moving radially.
 
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