Back to physics class with you!

You're close, but you're confusing energy and momentum. The mass of the bullet times muzzle velocity plus the mass of the propellant times about 5200 fps is equal to the mass of the gun times its recoil velocity. Your formula is for energy!!! You most assuredly DO NOT absorb the same as the target!!! With some of the big boomers, you might absorb 100 ft-lbs of energy, while the target receives 6,000 or so...

Pertinax

Does that answer everyones questions. I will video tape this but it will be a standard VHS tape. None of us have a digital recorder so I don't think I will be able to post the video. Any suggestions?

Kent

What type of 440 gr bullets do you use in the 500 Jeffrey?

Despite all of our pre-conseaved theories et al, we're rooting for the gut barrel shoot, and can't wait to see photos or video!

Equal and opposite "reactions" pertain only to forces, not either momentum or energy. You push on something and it pushes back. The resultant of all forces acting on a free body need not be zero (otherwise nothing could move) but at the moment that an impetus is delivered the force applied to the soon to be moving object and the applying object is balanced.

IF and ONLY IF, you can assume that the rifle is a rigid body (a reasonable assumption) then you can use a conservation of momentum approach to estimate the recoil velocity based on the masses and exit velocities of the bullet and combustion gases. The velocity of the gas is a little difficult to assess. Its going the same speed as the bullet immediately behind the bullet until the instant it exits, then accelerates due to sudden quasi-adiabatic expansion; but there is also a velocity gradient in the gas from the muzzle back into the chamber where velocity is zero.

Here's a freaky factoid for you to ponder. Did you know that the velocity of your bullet varies with the height and weight of the shooter?

Kent

The only concern I have with this test is the high water content. If you've ever shot a milk jug of water with something big, it explodes with violent force. I've seen one explode hard enough to smash the concrete block it was sitting on.

So, what if this "barrel 'o guts" explodes hard enough to damage the wooden legs it is sitting on? It will seam as if it was "knocked down" when it really wasn't. I know your gut barrel is bigger than a milk jug, but you're using a pretty big rifle!

The most accurate test I can think of would be to kill the steer. Then, prop its body onto a platform. Shoot it while it's dead and see if it falls down. That way you would have a more realistic test medium than anything you can make. If it's already dead, you can't blame any movement on nerve reactions or anything else....

I would advise not only tying the head to a snubbing post, but also secure the rear end so as to help keep your shots broadside to prevent any unnecessary meat damage.

Wow! Tomorrow's the big day!

Yes, I knew that.

Another interesting phenomena is that I was shooting a very small lady to shoot a Glock 17 in 9mm. The darned thing jammed nearly every time when she shot it, but it did not jam for me.

Turned out her wrist was too weak, so when the gun went off her wrist absorbed the recoil. Consequently, the slide did not slide all the way back and it jammed.

Now for an update. Shot the steer this morning and it fell like a 1/2 ton of beef. I shot it broadside just behind the front legs through the lungs. The witness said its knees buckled and down it went falling away from me. Teh exit wound was about
2 1/2 or 3 inches in diameter and there was blood and guts blown out to a distance of about 15 feet. Tomorrow afternoon we will get the barrel mounted on the legs and shoot it. I did not video tape the steer shooting. I figured everyone has seen an animal get shot down before.

Kent

My friend was observing he said that the side that I shot moved backwards and then the whole thing fell over. That pretty much matches was I thought I saw also and is very evident on the tape. Again the side I shot moved backward and then everything fell over.

I really did not think that this thing would do much of anything at all. Can someone explain this to me.

I plan on looking into getting the video tape made so I can post something here on the net. Someone will have to tell me how to post it though.

Kent

2. When a force operates on an object, the object accelerates proportional to the force in the same direction; and inversly proportional to its mass. F = ma

3. Objects interact through forces, when an object exerts a force on a second object, the second object exerts an equal and opposite force on the first. P = mv

You shot a bullet into a mass and some of the energy was transferred to the mass as the mass pushed back on the bullet. Forces are vectors, the mass moved in the same direction as the force exerted upon it. So I see all three Laws at work.

------------------

Sorry but this thread revolted me to no end!

Casey

Rogers explanation seems to contradict what everyone of the physics experts was saying would happen. That is why I was surprised to see the barrel fall over. I really agreed with the physics gurus. Do you think that some of these guys that said the animal would get knocked down were right?

Kent

The results you observed with the barrel are, amazingly enough, not really that different to the reaction of a live animal. It has nothing to do with MOMENTUM, which is the same (except for the additional gases expelled and a couple of other tiny variables) on each end of the gun, and everything to do with transfer of ENERGY, which is very different between recoil pad and bullet.

On a live animal, like your (humanely) butchered steer, the transfer of energy through hydrostatic shock disrupts the nervous system. If the energy transfer is great enough, as with a heavy caliber expanding bullet, this will happen even when a nervous system center like the brain or spine is not directly impacted. The animal then looses its footing and falls, frequently also loosing conciousness and expiring before regaining conciousness. You demonstrated this with the shot to the steer's thorax.

With the fluid-filled barrel, the hydrostatic shock transfered enough energy to throw the barrel's supports ("legs") off balance and cause the "inanimate 'animal'" to "fall". Had you been able to measure the deflection of the barrel itself due to momentum, it would have been minimal.

By the way, why didn't you just feed the steer guts to the pigs? They love 'em.

And if you shoot a live animal it is going to be knocked over if the bullet have much energy.

Living tissue has a high moisture content but it's not a mass of liquid. Gut any animal which has been head shot and the chest cavity is warm and damp, not filled with liquid. There is a lot of "water" or body fluid but it's dispersed throughout the body not carried in a big internal "water" tank.

The only liquid which will amount to anything is in the bladder. Not an easily hit target or even a good idea to aim for it!

My opinion is that to many people are confused by Muzzle energy VS momentum. Both 100% different and used interchangeable by many folks here, as seen in the posts.

The next is the body of animals being made up of "water" or fluids like a jug of water or something similiar. Nothing could be further from the truth. A Jug of water is far more explosive then a deers chest is.

No shoulder fired arm can lift or move a big game animal period. As far as knock down you need to disrupt the structure or frame as in the skeleton. Or the CNS, nothing else will consistantly fold them up at the shot. jj

------------------
Be very patient, remember the second mouse gets the cheese

The barrel was not filled with water either but the guts of one steer and about two and a half hogs. Since bullets travel through skin, muscle, and guts I figured that using real guts was as good as I could get! I am apologize if this test did not match your experience with wet phone books.

The steer seemed to fall over in about the same way as the barrel did. I am beginning to think that some of you scientific guys don't know what you are talking about. I intially agreed with all you physics experts but now after my testing which did not support your ideas you are saying that guts just are not representative of an animals innards! What planet are you from!!

Actually I don't care what you think. I did the test just because I could. I know that if I hit the animal in the right place it won't go far period. All this arguing is just for fun anyway. I just amazed at how such intelligent people can say such ignorant things simply because they have an opinion that differs from the results of a test.

Kent

[This message has been edited by Kent in IA (edited 02-12-2002).]

I said on a much earlier post somewhere that I have a .45-70 handcannon that will tip me over backwards every time I fire it if I don't take a small step backward. I have never suggested that a bullet striking an object exerts no force at all, only that its not very dramatic. That same .45-70 has bowled over a rotten stump with very soft softpoints and I made mention of that as well on my website and here. Shot with a hardcast solid, it never moved. The force relates the the rapidity with which the bullet accelerates to zero velocity. If it went to zero instantly the force applied would be infinite. In my experience infinite force is rarely applied.

If the four legs were nearly vertical then I would say there is a very good chance that it will tip over with most rifle impacts. Brace them solidly far apart and there is a small chance. I don't know what you did.

I know what I have done and I told you about that. I have drilled small game animals with very powerful rifles and they didn't twitch. I have repeatedly shot an object that fully absorbed the impact of very powerful rifles at handshaking range and nothing happened. That's not a bunch of physics, that's real world. I have spared everyone here a detailed analysis of the physics. I just told you real world results. No formulas and no BS. You gonna tell me now that my tests don't agree with your experience and therefore can't be real?

Where did I say that guts are not representative of an animal's innards? Huh? Misquote me and you will make me mad.

I suggested the bag of water because its not as disgusting to clean up and because a free swinging object will remove the question of the wooden sawhorses.

Laboratory testing by forensic scientists has clearly shown that water can be used as a fair target material (you get more penetration because the fibrous content of tissue is absent). [ JJHack, don't be too sure that the inside of a deer's chest doesn't swell much like a milk jug when a Ballistic Tip opens up inside. There is a lot of highly elastic tissue surrounding the lungs and what happens happens very fast. ]

Don't be so eager to see antagonism where there is none and let me be the judge of what I think. You are of course welcome to draw any conclusion you wish from your tests but this only repudiates the rather bold assertions of others, not anything I have argued.

As far as the legs are concerned I tried to replicate the way a steers legs are. Therefore they were pretty close to vertical. Believe me though it would have taken a pretty massive push to push the barrel over.

In all honesty after shooting the steer I wasn't all that surprised that the barrel was knocked over. That steer when down like he was struck by lightning! That was the first animal I have ever shot with my 500 Jeffery. It was awesome.

Kent

I never indicated even SLIGHTLY that the animal guts was a bad idea or that your test was a bad idea. I said,... (and you can go back and read it exactly) that no part of an animal is as explosive as a jug or container of water, because no part of an animal has a body part full of liquid! Open up a head shot animal and see for yourself, nothing will leak or drain out. I have seen several thousand big game animals killed, skinned and opened up in my career. Never saw one yet full of liquid that was head shot. Sure lots of liquid leaks into the chest when they are perforated in the chest. It's the only place it can drain into. However shot in the head the body cavity has no liquid containment system, except for the bladder. I feel, and as far as I know I'm entitled to an opinion here just as everyone else is, that a tank of water is not a fair representation of an animal. A keg of guts is an interesting idea, no place did I disput that.

Now if you want to debate a jug of water being just like a game animal bring it on, but don't go nuts claiming a said something I did not! Hell I did not even imply that!

How could you be so aggressive towards simple conversation here? I guess I'm still surprised by human nature and excentric adult personalities!

Just out of curiosity...how hard did that cannon kick you?

JJHack, if anything that I said antagonized you I apologize, though that was not my intent. I had no animosity at all.

You are correct that a tank of water does not accurately represent an animal's body, but most cells contain a large fraction of water and can be ruptured by a large pressure wave and will also behave much like a fluid under high pressure loads. Bullets fired into water exhibit a similar degree of deformation to bullets fired into soft tissue, which is why ballistic gelatin is used in forensic pathology. Naturally, there will be no free liquid if a bullet does not pass through tissue and nothing much other than blood leaks if a bullet does pass through, but that doesn't alter the fact that cells are fluid filled. I've seen some high speed photography of a bullet's passage and it creates a remarkable expansion cavity that is usually contained by the skin and muscles. When you get that stellate exit wound it because the bullet exited at the peak of the expansion (happens more on people than deer). Having said that I will readily concede that hitting a true bag of water will be much more dramatic. A fellow named Bill Steigers (of Bitterroot Bonded Bullets fame) tells me of seeing someone gut shoot a cow elk with a belly full of moss and water and watching her drop. Apparently that really hurts.

Just make sure the scene is well lighted and focused correctly, dont use auto-focus if you dont have to. To bad I cant record it with my equipment.

I think its a charming idea.........10

quote:

---

Originally posted by 416SW:
Kent
Thanks for doing the test and posting results. I shot a roo years ago with a 12ga slug and it flipped over backwards which is no mean feat with the tail they have. So I was surprised to read the physics "experts" say it was not possible.
Casey why did you keep reading it if you were so disgusted? It's not like Kent killed an animal just for the experiment.

---

I don't know why that k-roo flipped over backwards, but I doubt that it violated any laws of physics, even the ones the more educated here are insisting on. Just don't think the 12-gauge slug pushed the animal over backwards. Hell, shoot most animals with a one-ounce slug and they are bound to do some funny things, if they live long enough to do it. You ever seen what a chicken does when you cut its head off? What do you think old Ike (Newton, that is) had to say about that?

To keep this simple, but absolutely correct: itty-bitty one-to-two-ounce projectiles don't move animals much larger than a titmouse very far. What they DO do is fuck the animals up in various ways, and then the animal or gravity takes over, at least for a while. You can quote real physics applied correctly or incorrectly, or bogus physics applied any way you want, or tell me what you saw with your own two eyes for real, or for real while you were smoking wacky-weed, the first two sentences of this paragraph are still correct.

[This message has been edited by Recono (edited 02-12-2002).]

To keep this simple, but absolutely correct: itty-bitty one-to-two-ounce projectiles don't move animals much larger than a titmouse very far. What they DO do is fuck the animals up in various ways, and then the animal or gravity takes over, at least for a while. You can quote real physics applied correctly or incorrectly, or bogus physics applied any way you want, or tell me what you saw with your own two eyes for real, or for real while you were smoking wacky-weed, the first two sentences of this paragraph are still correct.

Recono
OK if we assume that the roo's nerves (slug exited through the spine) reacted and made it jump and it went over backwards because it failed to lean forward first. So we forget about the roo. How do you explain Kent's results?

I don't know what your problem is. I have noticed on other threads you have a fit if something or someone doesn't fit into your idea of the universe. Get over it. I have shot many animals over the years. I have seen them fall right over as if they were knocked over and I have seen multiple rounds pumped into them with no apparent response. I was trying to determine if a 500 Jeffery could knock over a mass that had a cross section similar to a living animal but without the nervous system response. I feel that I did about as good a job as can be expected.

Kent

I have shoot many mooses whit light calibers and whit 340 Wby mag. And when i have shoot a moose in the shoulder whit the 340 and hit bone then the moose have been knocked down.

I have followed your posts for a while now and I have a hard time deciding if you are serious or just pulling our legs here.....

A sad thing is that your posts seemes to bring out the worst in people here, that�s not the way things useally go around here!!

The tone is getting ruff in several posts above this one

I think it would be nice if you show some respect to the people on this nice place. Please don�t call people "sick" if they don�t happens to have the same opinions as you about how a big animal behave when hit with a big gun.

It won�t hurt you to be a bit humble from time to time!

By the way I have shot several Swedish moose with a .416 Taylor and 400 gr. softpoints in the sholder that didn�t flipped them over like they have been hit by a truck. Mabye you would like to explain that to me Overkill

Stefan

[This message has been edited by Stefan (edited 02-14-2002).]

As far as the "behaviour" being common and "get over it" I have no problem bud, try running a businees tied to the internet and you will see just how many jackA$$'s come out of the woodwork to screw with you!

------------------
It seems there is never enough time to do things right, but always enough time to do them over

quote:

---

Originally posted by 416SW:
[QUOTE]Originally posted by Recono:
[B] I don't know why that k-roo flipped over backwards, but I doubt that it violated any laws of physics, even the ones the more educated here are insisting on. Just don't think the 12-gauge slug pushed the animal over backwards. Hell, shoot most animals with a one-ounce slug and they are bound to do some funny things, if they live long enough to do it. You ever seen what a chicken does when you cut its head off? What do you think old Ike (Newton, that is) had to say about that?

To keep this simple, but absolutely correct: itty-bitty one-to-two-ounce projectiles don't move animals much larger than a titmouse very far. What they DO do is fuck the animals up in various ways, and then the animal or gravity takes over, at least for a while. You can quote real physics applied correctly or incorrectly, or bogus physics applied any way you want, or tell me what you saw with your own two eyes for real, or for real while you were smoking wacky-weed, the first two sentences of this paragraph are still correct.

Recono
OK if we assume that the roo's nerves (slug exited through the spine) reacted and made it jump and it went over backwards because it failed to lean forward first. So we forget about the roo. How do you explain Kent's results?

---

416SW,

I was commenting on the 'roo, but your question certainly seems reasonable. Except that I'm not even aware that what I said disagrees with Kent's results. Stonecreek and Harald explained it plenty well enough, although I believe that Stonecreek got momentum and energy reversed. Of course I could be wrong about that - I've forgotten more physics than I'll ever know again, which ain't saying much.

In case I haven't been clear enough, it sounds like Kent's experiment was reasonable, worked more or less as expected, and the rig fell over because the bullet pushed on it a little. I think the way the legs work is critical here, for bovines & gut-filled drums both.

If the bullet weighs 440 grians and its travelling 2500fps we have the force of 150 pounds pushing at the gut filled barrel, animal or treestump or what ever is hit.

If you come up behind somebody and shove them forward with 150 pounds of force some will fall, some will stagger forward and catch their balance, some may turn around and look at you funny! The reaction is going to be different in every case based on the balance ability of the person, the health, strength, and many other factors.

It would work out just as it does with an animal. Some fall, stagger, run, or even turn around and look at you funny, right before they charge!

I don't see this really giving us "new" information just confirming what most of us understood without having the time to prove it. One thing this should show is that the "calculated" 6000 plus FPE was not a factor in moving the barrel, but rather the 150 lbft of real "work" is what made the barrel move. Obviousley the barrel moved and did not fly through the air as if it were actually hit with 6000 pounds of force.

I would also suggest that a solid bullet would likely not have moved the barrel at all but ziped through with little transfered power. I have many times shot an empty aluminum soda can with a rifle and it remains up right without moving because the bullet just "zips" through.

If that same exact drum was hit with a 300 weatherby and a 180 grain bullet it would have given us 1/2 the Pounds feet of energy to move the drum. Do you think that would have pushed it over with 1/2 the effort?

interesting eh!

George