Posted on 10/02/2007 9:15:49 AM PDT by 7thson
Hey, I got a question for all the firearm experts/enthusiasts on Free Republic.
Speaking to my grandson recently - he is 16 - he told me a episode of Mythbusters where the look at the 'myth' shown in movies when a person gets shot they get blown back. The Mythbuster people concluded it was false by shooting a dead pig and a dummy. Also - and this stood out to me right away - they said that according to Newtons law - 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.
Now please correct me if I am wrong because I do not know much about firearms. But I told my grandson that mythbusters got it wrong. First, I said that certain firearms were developed for the sole purpose of putting people on their arse. And two - they got the law wrong. I said that when you fire a gun the reaction is the recoil. And that when the bullet hits the person, the opposite reaction is getting pushed back.
Can someone tell me if I am wrong or right. Also, does anyone know where I can link to the political belief test that indicates whether someone is a conservative, liberal, Stalinist, etc?
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.
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.
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.
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.
Kinda like the jerked tablecloth.
here’s a link to a site that does experiments on penetration, if it might be of any interest/help:
http://theboxotruth.com/
Whaddya mean? It never does get old!
Well, I think it's funny...
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/
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.
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
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.
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!
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.
Have you ever been bird hunting with Dick Cheney?
Just checking?
close. the .45acp was deemed to be enough to knock a man over who was running down and incline greater than 30 degrees.
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.
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.
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.)
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.
See http://www.freerepublic.com/focus/f-chat/1905413/posts?page=59#59 about the episode.
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