Story

Shooting Myths: Knockdown Power

Sandbag Stanley volunteered to test the "knockdown power" myth. He's a 50 pound bag of sand who wears a bulletproof vest.

Sandbag Stanley volunteered to test the "knockdown power" myth. He's a 50-pound bag of sand who wears a bulletproof vest.

Knockdown [nok-doun]
adjective

  1. Capable of knocking something down; overwhelming; irresistible: a knockdown blow.
  2. Internet lore referring to the ability of large guns like .45s and shotguns to literally knock people off their feet.

Last week, I wrote about Ten Examples of the Internet’s Worst Gun Advice, and that created quite the discussion! A lot of the conversation centered on the issues related to “knockdown power.” Some are still convinced that projectiles from a shotgun shell will knock someone backwards, through a plate glass window, or into the next county. Others got hung up on related issues, like stopping power or lethality.

I decided that this was a great excuse to go to the shooting range and do silly things, so let’s talk about the literal definition of knockdown power. I don’t mean stopping power or lethality or the capability of a cartridge to cause damage. Those things are pretty clear concepts. I mean literal knockdown power. Can a projectile fired from a commonly-available firearm knock someone off their feet? We aimed to find out—and brought a video camera along to document the experiment. There’s a link to the video towards the end of this article.

Since I couldn’t find any volunteers to get “knocked down,” I decided to use a 50-pound bag of sand as a stand-in substitute. Yes, I’m the adventurous sort. I’m stacking the deck in favor of the knockdown power myth. Even though an average Evil Dude is likely to weigh at least three times that, we’re going to see what various projectiles do to an object that weighs just 50 pounds.

One more thing. There was a lot of discussion in the comments last week about kinetic energy, bullets passing through targets, and the concept of energy dumps. So to make sure that our Sandbag Stanley absorbed all the gusto and enthusiasm that each round had to offer, we clothed him in a bulletproof vest. It’s for science, after all.

The bulletproof vest did a stellar job of capturing the energy from the .45 and 12 gauge projectiles. None of these passed through the target.

The bulletproof vest did a stellar job of capturing the energy from the .45 and 12 gauge projectiles. None of these passed through the target.

If this myth carries any weight at all, we’re going to see slight-of-stature 50-pound Sandbag Stanley go flying all over the range when hit, right? We didn’t have a plate glass window to put behind him, so we’re all going to have to imagine that part. Or maybe if OutdoorHub increases its CGI budget, we can add it in during post-production like the Hollywood folks do.

First up on the test was a .45 ACP. We used a full-sized Smith & Wesson E-Series 1911 government model. We didn’t want to risk any velocity loss using a shorter barrel than the original designed by John Moses Browning. We went ahead and skipped the 9x19mm, mainly because so many people are convinced that it couldn’t possibly cause as much destruction as the venerable .45. For ammo we went first-rate: Speer Gold Dot 230-grain hollow points. These leave the barrel at about 890 feet per second. Although the vest would certainly stop a full metal jacket bullet easily, we wanted to get maximum energy dump in the minimum amount of time.

The results? Meh. Even the potent and persuasive .45 ACP failed to budge Sandbag Stanley. Apparently he’s a stubborn sort.

Next up on the list was the AR-15. Some consider it far too powerful to be owned by “civilians.” Others are convinced it lacks effectiveness. We decided not to get caught up in that debate and simply see what Stanley felt about the whole thing. We used standard 55-grain full metal jacket projectiles traveling at 3,000 feet per second.

And? We could barely see anything happen in real time, but we could see the vest twitch when shots impacted during slow-motion replay of the video.

Given Stanley’s resistance to cooperating with the myth, we decided to up the ante and bring in the big guns. Next up was a Mossberg JM Pro 12 gauge. We loaded it with Winchester’s PDX1 Supreme Elite personal defense load. This one carries a double punch, sure to knock Stanley right into the next century. It has a one-ounce slug and three 00 buckshot pellets—all traveling at 1,150 feet per second.

As you’ll see in the video, there was some pretty dramatic energy transfer. The vest stopped the slug and the buckshot pellets, but made about a three-inch deep dent in Stanley. It made for impressive slow-motion video, even if it didn’t come close to knocking Stanley over.

These Winchester one-ounce slugs zipping along at 1,600 feet per second packed a wallop.

These Winchester one-ounce slugs zipping along at 1,600 feet per second packed a wallop.

At wit’s end, we decided to donate our shoulders to science and suffer the recoil of 12 gauge one-ounce slugs traveling at a whopping 1,600 feet per second. Our biggest fear, according to internet lore, was that Stanley would simply vaporize and leave a smoking crater in our shooting range. That, and the risk of creating a disturbance in a parallel universe.

Did it work? You’ll have to watch the video to find out.

Just kidding. It did, in fact, knock Stanley over. Barely, and with very little drama. He almost didn’t tip over at all—and he only weighs 50 pounds.

You can see the Adventures of Sandbag Stanley here:

Images by Tom McHale

Any views or opinions expressed in this article are those of the author and do not reflect those of OutdoorHub. Comments on this article reflect the sole opinions of their writers.
  • Scientist

    put Stanley on “legs” and try again

    • Leon Grimes

      Exactly!

    • BobH137

      Took the words right out of my mouth! center of gravity does not replicate that of a standing person!

      • http://mygunculture.com/ My Gun Culture

        That’s irrelevant to the point of the myth, ie the Hollywood thing of a gun “knocking someone off their feet” A gun isn’t going to send a 50 pound object flying, much less a 150 pound object or person, no matter where the center of gravity is.

        Besides, standing them up on legs doesn’t even address the concept of “tipping over” anyway as we have a continuous balance correcting thing called a brain which prevents us from tipping over as easily as a sandbag on 2×4′s.

    • Dave

      At most, putting Stanley on legs would merely result in it slowly tipping over.

      No firearm is going to knock a person backwards off their feet.

      • BobH137

        Unless it knocked the shooter on their ass too. Every action has an equal but opposite reaction

    • Vincent Urbano

      And distribute another 150 lbs over him. It ain’t even gonna move. People go down in pain and shock. They aren’t knocked down.

    • BigMike

      People fall down, they don’t get knocked backwards off their feet. Mythbusters did an entire episode on this and they hung their dummy from a nail so all it took to knock them off was enough pressure to move the hook off the nail. Less than an inch. They couldn’t even get it to move until they finally used some shotgun with a magnum load at close range. Even then it didn’t go flying 5 feet backwards. It practically dropped right where it was so it was just enough to move it off the nail it was hanging on.

  • Russ Riley

    I have to wonder how the results would have been if the body of the target was placed on two supports at 32 inches with two 12 x 4 inch bases representing legs and feet? Of course also giving a higher center mass and more top heavy as an actual person would be.

    • http://mygunculture.com/ My Gun Culture

      It would have still been barely tippy, although it wouldn’t tell us much as there is no “brain” like a person or Segway has to provide constant balancing correction. The point I was addressing was the “Hollywood” myth of a gun knocking someone off their feet and through the air in some dramatic way. We had to work pretty hard to get a 50 pound bag to gently fall over :-)

      • Robert

        You could try a 2 bore :) I’ve seen that knock the shooter over :)

      • http://mygunculture.com/ My Gun Culture

        Unfortunately my 2 bore was in the shop after a stray round blew up the Eastern seaboard :-)

      • Robert

        As long as you admit there is a capable knock down gun out there………..lmao………but it’s also a two way street!

      • hubcap52

        We should be so lucky

    • Dave

      At most it would just slowly topple over.

  • scott

    Even being closer to the ground, at 50 lbs that sandbag would have reacted if it was going to. You can whine about legs and height and all that. But if you want to do that the legs had better be 40 lbs each, fastened to the torso, and spring loaded to mimic a human’s sense of balance and the natural shock absorbtion of the body as it reacts to external forces. Be sure to add 15 lb arms that will flop around and dissipate energy while you’re at it… Since a sandbag doesn’t have a sense of balance I suppose it still might tip over when shot, but then again it might tip over in a strong wind so you’ll have to be accept that a particular caliber only has as much knockdown power as a wind gust if you go that route.
    ….. or you could just admit that bullets don’t move people around like in the movies. If you aren’t sure, you could ask somebody who’s been shot and survived and find out how far they flew if you don’t believe it …

  • SomeGuy102

    What I know about physics is that for every action there is an equal and opposite reaction… So a bullet can’t possibly physically impact a target any harder than its recoil. Reason the butt of a gun doesn’t pass through your shoulder like a bullet is because the energy is spread over a greater area and acceleration is slowed by the mass of the gun. So if the recoil doesn’t knock down the shooter the projectile won’t knock down the recipient either.

    • jng1226

      This! I guess none of the people that believe otherwise didn’t graduate high school, or even listen during basic physics.

  • Russ Riley

    Of course, nothing happens as in the movies, they need drama and wow factor. I have been shot and although it did not pick me up and throw me like I was sucked up in a tornado, it did knock me over straight backwards. I am 6 ft and 205 pounds. As to the comment from “someguy 102″, you might want to check ballistics and your understanding of physics, not being a smart butt here, just want you to check deeper. I seriously doubt any shoulder could handle the PSI recoil if said recoil was actually equal to the PSI impact a traveling round in most calibers is capable of. Regardless, very interesting subject and thanks for bringing up for discussion.

  • ghostrider1964

    Well done. My friends and I did similiar tests several years ago using a manakin with a class3 vest. Manakin never fell over even with 12 ga slugs from 10 yards. I have killed many animals and live in the country. I have seen the effects of a wide array of ammo from .22LR to .50 BMG. My truck gun is a Marlin GLB 45-70 with 405GC travelling at 1850fps. I have seen the results of it from rabbits to large hogs. They just fall very dead…

    • zipper

      got the same gun. ever try the Hornady Leverevolution 325gr. FTX @ 2050fps? serious medicine.

  • Tom

    If a shot would knock someone over, then the person shooting the gun would also be knocked over.

    • zipper

      not if the gun weighed 150lbs, or was fixed in place.

  • Mark 5

    I guess we can thank Hollywood for creating the myth in the first place. They often show people flying through the air backwards after being shot with a shotgun. The ant-gun folks believe this is true as Hollywood action movies is about the only gun experience they get and it is that which they base their beliefs on.

  • Tom

    Newton knew the answer to your questions way back in the late 1600′s

    First law: When viewed in an inertial reference frame, an object either remains at rest or moves at a constant velocity, unless acted upon by an externalforce.[2][3]

    Second law: The vector sum of the forces F on an object is equal to the mass m of that object multiplied by the acceleration a of the object; thus,F = ma. Force and acceleration are both vectors (as denoted by the bold type).

    Third law: When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

    • http://mygunculture.com/ My Gun Culture

      Yep! I wrote about that in the first article. Smart guy that Newton. But people still don’t believe until they see it, hence the excuse to go to the range and do silly things :-) And it WAS fun… Because… science!

  • Realist

    Next test we need to use cadavers. Maybe that will convince people that a body won’t fly through the air and dramatically crash through a plate glass window.

    • guest

      That was the subject of a “Mythbusters” episode. Large hog carcasses were suspended on chains. They filmed the bullet impacts with a high speed camera. The really big guns nudged them slightly.

  • BobH137

    I don’t care some much if I knock it down, just so long as both halves land where they stood.

  • Dough

    yeah center of gravity was too low in your test. build a target with a base the size of human feet out of plywood, then use 4×4′s for the length of the legs [ 3ft ish ], then a plywood base to set an 80 or even 100 lbs bag of sand on then put your vest on it and shoot it ! do it right guys dont throw a bag of sand on the ground shoot it and say myth busted , thats like testing glue without opening the tube

    • Aaron

      Soooo, make your test dummy the way you describe it. Then walk up to it and tap it on the shoulder and watch it fall, Then tap your buddy who came to the range with you on the shoulder with the same force. Did he fall over? If so, you’re both way to drunk to be at the range.
      Like Scott said above, it’s not that simple. Plywood and 4x4s don’t weigh nearly as much as real legs – make each leg 40 lbs and evenly distribute the weight over the span of the feet, and very firmly attach it to the bag of sand. What you’re describing has a center of gravity that’s not even close to a real body; if it was, we would all be falling over every time we tilted our heads back to drink a Pepsi.

      • http://mygunculture.com/ My Gun Culture

        Exactly. Center of gravity and lack of a continuous balancing mechanism (our brain) have nothing to do with this myth. All it intends to show visually is that a bullet isn’t going to send a 50 pound thing “flying” much less a 150 pound one. Because of that crazy Newton concept of “equal and opposite actions.”

        Whether we can create a rig to easily “tip something over” has nothing to do with the Hollywood myth of bad guys flying through windows, walls and doors when they get shot.

    • Dave

      Center of gravity would not have changed anything. If you put it on legs, the most that would happen is it might slowly topple over.

  • hubcap52

    You also stacked the deck in favor of the dummy by giving ‘him’ the bullet-proof vest which stopped the projectiles (effectively dumping all the kinetic energy at the surface (skin) level) instead of passing into/through the body as it would without the vest. Anyone who has hunted game will see the fallacy of this myth.

    • Dave

      The force still acts on the sandbag regardless of where it is applied. You can apply it in the middle or on the surface and it will move the sandbag the exact same amount. The point of the vest was to make sure that ALL of the force acted on the sandbag, eliminating the chance of a pass through.

      • hubcap52

        “The force still acts on the sandbag regardless of where it is applied.” That was exactly my point. If the bullet were to pass through, any kinetic energy left in the moving projectile would be expended on thin air or anything beyond the target, and therefore not affect the body/sandbag. BTW, since the bullets/slug were all pretty much stopped intact by utilizing a ‘soft stop’, vis. (BPV), as opposed to a steel plate that would likely have fragmented the projectiles, that means all the energy went into ‘Knocking Stanley down’, less that which was converted to heat.

      • Dave

        Roger, copy. Misread what you were trying to say, but tracking now.

  • zipper

    as far as physically lifting a person and flinging him through the air, no small arms round will do that. however, an observed “knockdown” could be achieved if the person was off-balance when struck, or on unstable ground causing a stumble and fall. “Knockdown” really doesn’t mean anything if, once down, the opponent is still able to function(as in pull a trigger). i’ll take a stopping round in CQB any day.

  • Oakspar77777

    A simple solution to the “it was a bag on the ground” whiners would be to hang a trashcan by two chains (legs) and fill it with a realistic volumn of sand (at least 100#). Then, shoot the can and watch how little it moves.

    For comparison, push the can to an equal amount of swing and them push your buddy with an equal amount of force. He is unlikely to even stumble.

    • Dave

      Yep. This is called a “ballistics pendulum” and has been used for centuries to study firearms and forces.

    • 2ThinkN_Do2

      Yep, a trash can is made just like the human body . . . . .

      • Oakspar77777

        You could hang a grain sack full of 2-liter bottles of water or cans of soda if you like. That would give you the weight, chunkiness of the human form, the liquidity, and the mass.

        Won’t make a difference. Physics still win.

  • Josh

    Try a . 50 sniper rifle or .50 Beowulf round. And yeah put it on legs or measure how much foot pounds it takes to push someone off their feet then compare that to the foot pounds given off by getting hit by different kinds of bullets

    • Ziggy

      I shot a guy with a 38 special Super Vel hollow point he he just sort of fell over. I shot a guy with 2 3/4″ OO Buck and before falling over in pain said, “who in the f..k shot me?” You can shoot someone with a RPG and they just blowup. Same with a .50 caliber and most of the person just blows up where they were hit. Soooooooo, bottom line, people that are hit just go down not backwards.

    • Dave

      You mean a .50 BMG? Still will not make a person fly backward. Nor will the far less powerful .50 Beowulf.

  • GABubba

    Mythbusters, 2005. Episode 25 and revisited in episode 38. “Busted” in both episodes, episode 38 using a .50 caliber…

  • Marc Middleton

    I was shot point blank in the gut with no.1 buckshot 12 shot, 11 still in me the 12th broke the skin in my back and was removed at scene, I was still standing after shot and climbed out of Creek and crawled 8 ft and layed down and waited for help. No vest or armor

    • 2ThinkN_Do2

      Still standing, but climbed out of a creek, how does that work?

  • Chris

    Unless they had a vest on, these would all pretty much just pass right thru on a center mass shot..there’s nothing really there..ribs and lungs..pretty ‘airy’..
    Look what happens when you slug a deer..
    Sometimes they go down for a second and get right back up and run a hundred yards..
    Depends where ya’ hit’em…what vitals you take out..

    Think their point is, the crap they do in the movies, where the guy goes flying 10 feet thru a plate glass barbershop window after being shot, is BS..

  • Varian Wrynn

    I’ve already stopped watching Hollywood movies that feature guns as they are totally devoid of realism. Shotgun blasts that blow a person through a wall, full auto M-16′s and AK-47′s laying around on the street, you get the picture.

    Nice experiment, though.

  • peter

    or stack 3 bags, and shoot the center, or the upper. watch him dance.
    Nesting the bag in soft foam on the ground helps too.

  • Dave

    Good job! I’d have done it as a ballistics pendulum (those who never took physics is school might want to look that term up), but still, the results pretty well demolish the idea that muzzle energy or kinetic energy predicts that a hit from a .45 ACP will send someone flying backwards.

  • IQGenius

    This is just a DUMB demonstration. Proves NOTHING.

    • Dave

      It proves that a .45 ACP, etc will not fling a person backwards as often portraryed by Hollywood or believed by people who do not understand muzzle energy/kinetic energy or basic physics.

  • Alamoaquaman

    There is so much wrong with this I don’t know where to begin…lol I wouldn’t have posted such a poor (I hesitate to use the word) ‘experiment’

    • Dave

      There is very little wrong with the “experiment” except that it does not support the preconceived, Hollywood enforced notions held by a lot of people.

  • uzimandias

    Nothing that Newton wrote suggested that a bullet capable of knocking down the person being shot also necessarily must have knocked down the shooter. That claim is a misinterpretation/misapplication of the Laws of Motion.

    The 3rd Law is irrelevant in this case because there is no principle requiring that the bullet arrive at the target with the same energy as it left the muzzle with. Ergo there is no guarantee of “opposite-but-equal.” Barring a contact shooting, the bullet _will_ lose KE while in flight, which would constitute a violation of the 3rd Law. Outside of special circumstances (primarily Einsteinian or quantum physics), there can be no exceptions to Newton, therefore the 3nd Law has no standing.

    What IS applicable is the 2nd Law, F=ma.

    The tricky bit about the 2nd Law is that third term, the ‘a’, which stands for ‘acceleration’, the formula for which is: a=Δv÷Δt. Acceleration equals the change in velocity divided by the change in time. Substituted into Newton’s base formula, above, we get: F=m*(Δv÷Δt)

    If we stipulate that the mass of the bullet does not change, even the 2nd Law does not guarantee that the force applied to the target will equal that applied to the shooter, even if we arbitrarily stipulate that KE is equal at both ends, because there is no property of physics that assures the negative acceleration at the one end will equal the positive acceleration at the other. Point of fact, in real world shootings, the energies deposited at either end almost never will be the same.

    Applying the 2nd Law, if you reduced the projectile’s rate of acceleration by dramatically lengthening the barrel, using a slow-burning powder, such as black powder, and a very heavy bullet, it would be quite possible to build a gun capable of knocking a man down but leaving the shooter standing. But the resulting rifle would not be anything I would be eager to carry on my next deer hunt.

    That no one has yet built a practical firearm that will do this it is not the same thing as the laws of physics prohibiting it. Newton’s laws state that it IS possible, not that it isn’t. But possible and practical don’t always slop at the same trough.

    • Gigs

      50BMG has enough energy to possibly knock someone over if they didn’t have good footing, and assuming it didn’t zip right though them.

      BTW losing velocity in the air doesn’t violate the 3rd law, those air molecules that the bullet displaces are gaining velocity either literally or in the form of heat (which can be viewed as a kind of velocity). If there were no air to collide with, the bullet wouldn’t slow down (except for gravity effects, which are minimal, and also follow the 3rd law since the bullet also accelerates the earth some microscopic amount!)

      You are correct in that the peak (i.e. instantaneous) recoil acceleration doesn’t necessarily equal the peak impact acceleration because the bullet accelerates over a longer distance over the length of the barrel. But the whole point of citing the 3rd law is to simplify it for people who think that guns work like movies and throw people around when they are shot.

    • Dave

      “The 3rd Law is irrelevant in this case because there is no principle requiring that the bullet arrive at the target with the same energy as it left the muzzle with.”

      Considering that the bullet will always arrive at the target with less KE than it had when it left the muzzle, the 3rd law is absolutely applicable. If it is going to throw a person backwards, then it will have to have an even greater affect on the shooter.

      “What IS applicable is the 2nd Law, F=ma.”

      Absolutely. Momentum, specifically the conservation of momentum, is what people should be focusing on, not kinetic energy.

      • uzimandias

        “Applicable” was a poor choice of words. I should have said “controlling.” The 3rd Law is applicable, it’s just that nothing Newton ever said (or implied) requires that the application of his 3rd Law at the end doing the shooting has anything to do with the application of the same law at the other end.

  • 2fishandhunt

    I am not a scientist, but I believe a similar test would be interesting with a steel plate with gages that show just how much energy is being transferred to the plate from the bullet impact. I believe we have seen much about penetration, but I have not seen one like the one I described.

    • Gigs

      It would be difficult to get a load cell capable of such high pressures and also fast enough to capture a good trace. You could capture the flex with strain gauges a little bit easier, but that would be tricky to convert into overall force. A pendulum like someone mentioned would be much easier.

  • 2fishandhunt

    I would like to see a .50 Barret, .44 Magnum, .460, 30-06 and 300 win. Mag. also.

  • 2ThinkN_Do2

    So this test actually proves nothing. A human is not dense like a bag of sand. A human does not generally have a base under them that is wider but has lanky legs with joints that bend. A human torso in many cases likely weighs very similar to this bag of sand, so the fact that this is only 50 lbs has nothing to do with it. The bag does not have a mind, and therefore the hit it takes does nothing to affect the balance equilibrium which could be affected in a human. The only real test, is by those who have shot people in real life and the results they’ve shared.

    • http://mygunculture.com/ Tom McHale

      It only aims to demonstrate exactly what it says:

      “Some are still convinced that projectiles from a shotgun shell will knock someone backwards, through a plate glass window, or into the next county.”

      Since that’s physically impossible in our universe, it shows that visually, and nothing more. This “test” doesn’t claim anything remotely related to incapacitation, injury, “stopping power” or anything else – only that a bullet can’t knock a heavy object backwards. There’s just not enough energy there.

      • 2ThinkN_Do2

        No, it doesn’t prove that, because as I stated, a human is not a bag of sand. The energy transfer through a fluid body would be different from that of a bag of sand. The sand granules have space between them and are not connected one to the other. When the flesh of a body is hit, the force transfers to other parts that are all interconnected. And as I stated, there is more at play here than an inanimate object. But who cares, when the time comes (hopefully never) you shoot till the threat is stopped.

      • http://mygunculture.com/ Tom McHale

        Read the article carefully :-) There is near 100% energy transfer and no sand is touched. All the energy is “captured” by the bulletproof vest – so whatever momentum a bullet has is applied. But that’s irrelevant anyway, there is not enough momentum to move an object of any kind, of that weight, with any type of energy transfer in a bullet or shotgun slug.

        This has nothing to do with interconnected parts or fluid or shock or anything remotely like that – it’s a simple matter of whether the energy of a bullet has enough momentum to physically move a person. It doesn’t. Laws of physics. The person may move on their own accord for a thousand different reasons, but a bullet cannot move an object the size of a human like that.

      • 2ThinkN_Do2

        Watching the video in slowmo, slug bounces off the bag; that wouldn’t happen to a human (unless wearing a vest with plates, yours had no plates) and therefore the transfer of energy would be different through the body. In addition, the sand bag was stabilized in the foam, where it actually touched the ground through wholes in the foam.

      • http://mygunculture.com/ Tom McHale

        Just for the record, and I was the one who shot the target and video, no slugs bounced off – they were all caught in the vest and I had to dig them out. And the whole mess was balanced on the platform, not supported, and not touching the ground. Physics doesn’t lie :-)

      • 2ThinkN_Do2

        Well I watched the video in slow motion and I see something bounce off; maybe it was the 3 small buckshot from the PDX. As for the the bag, watch your own video. The bag sags down into the holes in the bottom of the foam tray, that is a couple inches thick. If the bag were just sitting on top of a sheet of plywood for example, it likely would have fallen from the PDX, but it rebounded within the base. A human wouldn’t react that way. Humans do not have a footprint larger than their chest area. Myth not busted.

      • Gigs

        It was probably the shot card or whatever was under the load.

      • http://mygunculture.com/ Tom McHale

        Exactly – that vest does a beautiful job of trapping everything. It stopped the slugs and all pellets cold – had to dig them out from dozens of layers of the Dyneema material.

      • Dave

        If all the energy is transferred into and contained by a body, the resultant movement of said body will be the same.

        Again, the kinetic energy is actually not the factor people need to be looking at as most of the KE is converted to heat. The number people should be focused on when it comes to the ability to move something is momentum.

  • HerbWalsh

    More realistic if Stanley was talk’in smak

  • Chris Mcmillan

    The test is not valid….There is numerous confirmed shootings with a .45 using FMJ ammo in Vietnam that knocked a bad guy on his butt or hit him in the shoulder causing him to spin and stumble backwards.

    • Sez Eye

      Most of this reaction comes from the muscle reaction of the person hit, not from the impact itself. Your body naturally attempts to avoid the pain that comes from being hit from a bullet and will spontaneously react to the pain input by moving the body away from what it perceives as the source of the pain.

  • 2fishandhunt

    Thanks Gigs, you make excellent points. This shows me that you are a thinker and better informed than I am.

  • Michael Sabbeth

    creative and informative presentation. thanks

  • John Cline

    think your center of gravity may be wrong..?

  • uzimandias

    F=m*(Δv÷Δt)

    Say you had a McMillan Tac-50, 36″ barrel, shooting 750-gr A-Maxes, loaded to 2800 fps.

    And say you shot a guy at a range of one inch (1″) who happened to be wearing a ballistic vest with ESAPI plates.
    ESAPI will not stop a .50 cal round, but it will slow it down. So for sake of argument, let’s further conjecture our A-Max only penetrates to a depth of exactly six inches (6.00″) measured from the surface of the plate.

    The mass of the bullet on impact is equal to its mass at muzzle exit.
    And its velocity on impact, for all intents and purposes, is the same as at muzzle exit.

    However, owing to the difference in the acceleration distances involved (6″ vs 36″), the bullet accelerates from 2800 fps to 0 in one-sixth (1/6) of the time in which it accelerated from 0 fps to 2800.

    And F=m*(Δv÷Δt).

    That necessarily means that the force received by the target from the bullet’s impact is six times (6x) greater than the force the same bullet applied to the shooter when he launched it. And that’s 6x more manly momentum, which must be conserved, not 6x more of that girly kinetic energy stuff, which tends to be rather flaky about showing up for work.

    Opposite? Yes. Equal? Not even close.

  • logun

    Doesn’t density come in to play here?

  • jdog777

    weak…. forgot to consider the center of gravity.

  • BigMike

    Mythbusters did a whole episode on this. The whole flying backwards thing when shot is all Hollywood. People usually fall down but not even always.

  • kanejp63

    There’s plenty of video floating around the internet of people (with legs) getting shot with all kinds of different calibers of bullets.

  • John

    I think if you are a little person named Stanley with a gun , you would be in big trouble………….aka, shorty……

  • Bill

    Why not go for broke and use a Barrett 50 cal??? The movie that comes to mind is smoking aces when the victims are literally flying through the air when hit. Get a 150-200 lb dummy and see if it works. The approximate energy a 250lb linebacker has at traveling 15mph is roughly 28000 joules. A 50 cal is roughly 18-20,000 joules. Not too far off. And I’m sure you get hit by that linebacker at that speed he’ll knock you straight on your ass sending you back a few feet.