# Knockdown Myths Dispelled



## dmax999 (Feb 20, 2005)

This last week on the Discovery Channel, the MythBusters did an experiment on the Hollywood type knock backs from being hit by bullets.  They first used a pig carcus and precariously hung it so it could easily be knocked down.  Any guesses on which caliburs knocked it down?  Of course the "wimpy" 9mm didn't, but neither did the 45 ACP, 44 Magnum, .223, or .308.  It barely moved for any including the entire cast all hosing it down with all these caliburs at the same time.  Only thing that moved it, and just barely, was a shotgun slug.

Later on it was tried again with their crash test dummy and a bullet proof vest, because they thought rounds leaving the target was the reason there was no effect.  With the vest the exact same results.

I always suspected this, because of Newton's laws the shooter would be knocked back/down just as hard as the target.

I'm a big fan of smaller faster moving bullets (like 223), and this is just more proof that the bigger caliburs don't really seem to have much advantage in combat.

I'd like to hear from anyone who thinks their experiments were invalid and why.  I'm sure there are some reasons, but I couldn't figure out any myself, but I'm also biased towards the results they found too.


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## hardheadjarhead (Feb 20, 2005)

Honestly, I don't see anyone but those outside the gun community still using the phrase "knockdown power."  Usually the uninitiated say that, and some of the old, old, old timers.

The current debate is "stopping power," not "knockdown power."



Regards,


Steve


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## GAB (Feb 20, 2005)

Hi, 

You need live targets, the knockdown is in the reflex of the item being hit and falling and receiving the strike either in flesh or a skeletal strike...

Yes, Hollywood is wrong and most of the persons who enjoy movies go for the unreal and just to be entertained...

If you want to see someone go down pretty fast it is to hit them in the area just above the belly button or below it, major reflex and involuntary reaction...

The old saying gut shoot, or gut shot is true and ugly...

A good test is against a big water melon or cantalope Hydrostaticshock, does it all the time...Shoot gallon jugs with water in them... I remember the slow motion pictures of the cattle that were being shot by a bullet traveling at close to 5000 ft per sec. unbelieveable what happens in that split second..
Got to have seen it to believe it... 

Quite a bit of difference in the weight and feet per second, reduce the weight and increase the speed or reduce the speed and increase the weight...

One ounce+ of lead at 1400 feet per sec is pretty brutal, 500Grain at 2000 + is pretty impressive... 55grain at 4000 feet per sec will go through 3/8" mild steel (hole in steel pressure and temperature) the friction and heat is what does that...molten metal on the other side...

I used to have a set up for testing. A 2'x2' 1" piece of steel on edge and placed in such a way that it will move... It would tell you things you don't see on tv...Bottom line is the 223 and the 308 are pretty good at what they do...

Type of bullet is a real big thing in delivering shock to the object.
45 at 10 feet into a water melon will tell you what you want to know also...

Regards, Gary


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## tsdclaflin (Feb 21, 2005)

When I deer hunt, I expect my shot to kill the deer, not to push him over (ie knock him down).

I don't know about people getting shot, but I would expect the shock, pain, etc would cause someone to go down.


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## Jerry (Feb 22, 2005)

The information I have from many sources contradicts this. Pain / shock is not all that good at making someone go down quickly; with enough adreneline it's rarely felt.

Anyone who hunts should be able to relate. If you don't destroy part of the central nervous system, or part of the locomotive system, how far can that deer run?

Same with people. While I won't rule out someone falling down from (if nothing else) loosing his concentration / balance, the only two ways to guarentee someone is down are to destroy part of the central nervous system responsable for locomotion (brain, spine, etc), or destroy part of the locomotive structure (break the pelvic girdle or a bone in the leg).


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## dearnis.com (Feb 22, 2005)

> Anyone who hunts should be able to relate.



That addresses this debate better than anything else.


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## TonyM. (Feb 22, 2005)

I've observed that unless there's hydroshock involved or a headshot(not recommended for anything) people respond to being shot not unlike deer.


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## psi_radar (Feb 22, 2005)

When shooting deer or elk with a lung shot, typically there's a flinch, the legs kind of twitch, and depending on the shot, they usually run a little ways, unless you were lucky enough to tag the heart or destroy the shoulder joint on the way in. I haven't attempted a gut shot or pelvic shot on anything, since those shots can highly compromise the meat. The animals don't really get knocked back though, though they do react. You can see the impact, the muscles move, possibly a stumble, then they move as quickly as they can until their systems fail.


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