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MYTHBUSTERS

Posted on 10/02/2007 9:15:49 AM PDT by 7thson

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To: 7thson
Mythbusters got it pretty much right (you might get shoved back but you won't fly through the air) but there are so many variables involved that a categorical statement is or should be impossible. Recoil, for example. Yes, power generated by a firearm is subject to Newton's second law, (which is probably unconstitutional but there you are). However, toward the shooter that force is distributed through the recoil system of the firearm, which serves to draw out the force over time, and the mass of the firearm as well as the shooter. The target receives the entire force through the cross-section of the projectile, a far smaller and more intense distribution. Same force, smaller area, shorter time.

To make it more complicated, not all of the energy of the bullet is transferred to the target all the time. If it penetrates the target there will be residual energy. If not, not.

Can a shooter get knocked down by recoil? You better believe it, I certainly have been. First time I shot a 12-gauge I was standing on a slick surface and my feet went out from under me. My brother thought it was funny to see me on my butt but I managed to keep the muzzle downrange and out of the mud. Too many witnesses to shoot him at the time, dang it.

I mention that to indicate how many variables there are in shooting in the real world. Shooting a fixed target in a laboratory isn't like shooting a crack-maddened mime on a unicycle when you're on roller skates yourself. At least I don't think so. Never tried it.

41 posted on 10/02/2007 11:42:20 AM PDT by Billthedrill
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To: 7thson

If you’ve ever shot a steel plate match, it’d be pretty obvious that Mythbusters got it right. 4-foot pepper poppers have to be balanced pretty close to vertical for even a 230gr +P .45ACP to knock it down. That’s a steel plate weighing in the neighborhood of 35-40 pounds, vertical, on a rotating axis located 2-4 feet below the area of impact, with 100% of the bullet force being transferred to the plate. Twist the set screw a few turns and even a .45 won’t knock it back. 9mm shooters learn about this phenomenon quickly since the .45’ers seem to think the joke never gets old.

Likewise, as another poster noted, I’ve shot deer — weighing anywhere from 80-130lb — with a .50 cal 350gr muzzleloader (about 1500 ft/lb), with a 12gauge shotgun slug at about 1500 ft/lb, and with a .270 (140gr) at about (2000 ft/lb). All of them broadside. None even fell sideways—they all just take a step or two and then die. If those extra heavy / slow or light/fast bullet combinations can’t blow a normal sized deer back, it won’t do it to a person.


42 posted on 10/02/2007 11:42:52 AM PDT by FateAmenableToChange
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To: Little Ray

A friend of mine that served in Somalia said that one of the problems they faced when shooting the bad guys was that they didn’t know that they were supposed to fall down and die like on TV or movies!

They’d get shot and keep on moving.


43 posted on 10/02/2007 11:58:49 AM PDT by Eagle Eye (If you agree with Democrats you agree with America's enemies.)
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To: FateAmenableToChange

Having taken the full blast from a 16 gauge shotgun with #4 birdshot (152 bb’s) at point blank range in the chest, I assert it did not blow me backwards. It did hurt like hell and leave some nasty scarring however. Had I had a solid steel shield on my chest, I would not have the scarring, but would have been “pushed” by the round’s force.

I am happy to be here and be a FReeper too.


44 posted on 10/02/2007 12:01:13 PM PDT by crazyshrink
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To: Holicheese
In layman's terms...without all the “mass + energy times squared”.....I say the bullet is too small and just simply pierces right through.

Kinda like the jerked tablecloth.

45 posted on 10/02/2007 12:03:59 PM PDT by shbox
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To: 7thson

here’s a link to a site that does experiments on penetration, if it might be of any interest/help:
http://theboxotruth.com/


46 posted on 10/02/2007 12:04:41 PM PDT by BorisTheBulletDodger
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To: FateAmenableToChange
9mm shooters learn about this phenomenon quickly since the .45’ers seem to think the joke never gets old.

Whaddya mean? It never does get old!

Well, I think it's funny...

47 posted on 10/02/2007 12:05:50 PM PDT by Billthedrill
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To: BorisTheBulletDodger

As for the political test you inquired about:

Simply google political test and be ready to look at many.

Here’s 1 example.

http://www.politicalcompass.org/


48 posted on 10/02/2007 12:10:23 PM PDT by crazyshrink
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To: Eagle Eye

They need to change out the ball ammo for semi-jacketed rounds... hollow points if possible. Unless they’re shootin’ at other armored troops.

Heard that story before, too, long ago. My uncle was usin’ an M1 Carbine, shooting at a Jap. He said he could see the puffs of dust coming off of him where he was hitting - and the Jap just kept runnin’! Then the guy with the BAR got him...
I think that is a universal cry of all troops: “Bigger guns! We need bigger guns! Big ‘effin’ guns!”
I don’t know if I’ve ever heard of US troops being completely satisfied with their weapons.


49 posted on 10/02/2007 12:18:22 PM PDT by Little Ray (Rudy Guiliani: If his wives can't trust him, why should we?)
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To: 7thson
every action has an opposite reaction - that when the person gets blown back it would mean the shootist would get blown back the opposite direction..

This is correct. The energy recieved cannot be more than the energy transmitted.

Watch some of those old WWII newsreels from the D Day invasion. Soldiers who are shot simply drop. No standard issue military small arm has enough energy to knock someone backwards.

L

50 posted on 10/02/2007 12:21:57 PM PDT by Lurker ( Comparing moderate islam to extremist islam is like comparing smallpox to ebola.)
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To: 7thson
The principle in question is conservation of momentum. For a person to be thrown back by a bullet, requires the bullet to impart that momentum to the person.

Suppose a 300 grain (20 gram) bullet is moving at 500 meters/second (which is fast).

The momentum = m*v = .020*500 = 10 kg-m/sec.

Assuming all of that momentum is transferred to the body (i.e., it's an elastic collision, so that none of the momentum/energy is dissipated into soft tissue), that's how much momentum the body will have after being hit.

Now assume that the target weighs 180 lbs (82 kg). By conservation of momentum,

m1 * v1 = m2 * v2

Solving for the target's velocity after being hit,

v2 = m1*v1/m2 = 10/82 = 0.12 m/sec = 0.4 ft/sec.

Which isn't close to being enough to throw you anywhere -- you might take a step back, but that's about it.

And, of course, there is a LOT of energy dissipation when a bullet hits a body -- the collision is not elastic. So the result will be even less.

But of course, we already knew that: the momentum imparted to the bullet was matched by the momentum imparted to the shooter, and he didn't get knocked back, either.

51 posted on 10/02/2007 12:24:17 PM PDT by r9etb
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To: Little Ray

I had heard that about the M1 Carbine when used in Korea. The Chinese had so many layers on, just trying to keep warm that the bullet didn’t do much damage.
I still love the M1 Carbine. Looks so cool even when its not being fired!


52 posted on 10/02/2007 12:24:22 PM PDT by Holicheese (1-21-09 Hillary starts to destroy America!)
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To: 7thson
Now, I was under the impression that a firearm was built for the US Army during the Philippine Insurection back in the 1900's that would knock down on their arse who they were fighting because the natives were so popped up on native drugs that ordinary pistols did not stop them. Is this true?

Sorta. The .45 Automatic was developed in response to the Moro attacks during the Philipine Insurrection, but the idea was just to drop them in their tracks, not blow them backwards.

53 posted on 10/02/2007 12:30:12 PM PDT by Bubba Ho-Tep
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To: crazyshrink

Have you ever been bird hunting with Dick Cheney?

Just checking?


54 posted on 10/02/2007 12:52:47 PM PDT by Tenacious 1 (No to nitwit jesters with a predisposition of self importance and unqualified political opinions!)
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To: Bubba Ho-Tep; 7thson

close. the .45acp was deemed to be enough to knock a man over who was running down and incline greater than 30 degrees.


55 posted on 10/02/2007 12:56:53 PM PDT by absolootezer0 (stop repeat offenders- don't re-elect them!)
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To: 7thson

That is correct. Kennedy’s head moved forward about two inches from the rear bullet impact. A couple of movie frames later, he moves to the rear and to the left.


56 posted on 10/02/2007 8:17:06 PM PDT by Shooter 2.5 (NRA - Hunter '08)
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To: Eagle Eye
A friend of mine that served in Somalia said that one of the problems they faced when shooting the bad guys was that they didn’t know that they were supposed to fall down and die like on TV or movies!

They’d get shot and keep on moving.

See, the problem is that no one told the Somali's that they were the bad guys. They probably thought they were Bruce Willis in Die Hard 1-4, not Victim #56 in Rambo II.

57 posted on 10/03/2007 2:33:21 AM PDT by FateAmenableToChange
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To: Ramius
I think for most bullets in most situations, Mythbusters got it mostly right.

That would be because they actually fired bullets into pig carcasses of the right weight to simulate a human being, and measured the effects.

And they used all kinds of ammo. You can sit on you butt and speculate, or you can do the research. (Not speaking to you, here.)

58 posted on 10/03/2007 2:41:12 AM PDT by js1138
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To: wideawake; 7thson

I watched the episode. They used different calibers, including a shotgun (can’t remember if it was 12 or 20 gauge). The myth was not knockdown power but sending the shootee flying when they are hit by the projectile. The fact is that even with a shotgun you can not send the shootee flying.


59 posted on 10/03/2007 12:04:56 PM PDT by looscnnn (DU is a VD for the brain.)
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To: JamesP81

See http://www.freerepublic.com/focus/f-chat/1905413/posts?page=59#59 about the episode.


60 posted on 10/03/2007 12:07:06 PM PDT by looscnnn (DU is a VD for the brain.)
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