Mythbusters...

[Lupinus]

Good question: how do they recover high power rifle
bullets for forensic comparison test?

I know you can use balistic's jelly but that deforms the bullet as if it went into a body so I dont know if that would work. I would thing you would want an undeformed bullet to get the best look at it for marking's.

Maybe if they break the surface tension of the water? Think high diving. With flat water you will get hurt but if you turn on a pump that make's a stream, like a fountian, onto the water it breaks the surface tension and the high diver is uninjured. So perhaps if you broke the surface tension you could fire it.

 

[Correia]

Lupinus, that is ironic, since breaking the surface tension of water to lessen impact is one of the myths that they busted in another episode.

 

[Dr.Rob]

so did the tracer blow up the gas tank or not?

 

[MechAg94]

On that "Deadly Weapons" video tracers did not ignite the gas.

 

[Phaetos]

I'm gonna add to this. I just watched an episode where they were testing the myth of jumping into water to evade being shot at. Would the water throw the trajectory off or does it actually go straight down as in the movies? They put the ballistics gel into a contraption that allowed them multiple depths at what appeared to be about a 23 degree +/- entry angle. The 1st test was with a Black Power Civil War replica, 1000f/s they said. At 5 feet, the round ended up 25 feet AWAY from the gell target in the pool. At 3 feet, the round was in the gel. Next up, a .223 rifle with Full Metal Jacket(of course they didn't say which brand). At 5 feet, the round came apart completely when it hit the water. It just shattered into pieces before the gel. At 3 feet, a small bit of the round actually impacted the gel. Odd I thought. Then they brought in the M1 .30 caliber. Same results. The round completely shattered. Odd that this same gun passed straight thru bullet-proof glass in their tests. I am currently waiting for them to test the .50 cal to see what happens. They are claiming 3000ft/sec for it. oh my god! Jaime says "So the safety's off now?" The girl says "I would think so, yeh"! Where are the gun experts?! Didn't penetrate the gel at all. Fell apart at 3 feet. This is confusing to me. Why?

 

[Lupinus]

Lupinus, that is ironic, since breaking the surface tension of water to lessen impact is one of the myths that they busted in another episode

They are known for being wrong you know

 

[Creeping Incrementalism]

Ok, they busted the .50BMG... what about hte .577 Tyrranosaur??? Hmmm???? (i just wanna see one fired...)



Berek

http://www.accuratereloading.com/index.html has video of people who mostly look inexperienced with elephant guns getting knocked over with a 577 Tyrannosaur (I'm not saying they go flying backwards, but rather that they lose their balance). Unfortunately, you now have to register on the forums to see the videos.

 

[JohnKSa]

video of people who mostly look inexperienced with elephant guns getting knocked over with a 577 Tyrannosaur

That's the thing--they are experienced with elephant guns. The .577 has ballistics that are very similar to the .50BMG but out of a normal size & weight gun without a muzzle brake the size of your head.

 

[bamawrx]

I enjoy the show, but they really need to hire me to help with all the gun episodes.


Dr bob, Tracer DID ignite gas tank at a distance. But up close the tracer would not set the gas aflame.

ps not explosion, just fire.

 

[Kurush]

Didn't penetrate the gel at all. Fell apart at 3 feet. This is confusing to me. Why?

There was just a big discussion about water and bullets in the general forum:

http://www.thehighroad.org/showthread.php?t=160272

 

[Bad Words]

Mythbusters did one episode where they determined that Archimedes' burning glass (He used mirrors to set a fleet of ships afire) wasn't possible.

MIT wanted to know if it was possible, too. They succeeded in setting fire to the ship in under 10 minutes.

Mythbusters also did one where they determined you couldn't get shocked by pissing on an electric fence because there would be too many gaps of air in the stream of urine. My cousin told me about this episode when we came across an electric fence. To his horror, my cousin proved mythbusters wrong on this one, too. The wire was about 18 inches from the ground and he had a good stream going due to having a couple 40's in him. Not sure what the specifics were on Mythbusters.

 

[Lupinus]

last time I checked when I take a leak with the possible exception of getting it going and when its about over it's a pretty solid stream heh

 

[artherd]

Kari with the M4 in the 'bullet knocks you back' eppisode = hot.

 

[Carl N. Brown]

Mythbusters opens their seasons with a Myth Revisited
show where they recheck themselves if viewers spot errors.
Veeerry unlike the big news media. Even though they do get
things wrong (the phosphorus as the paint on the nose
of an indendiary bullt [its a plug in the base of the bullet])
they have credibility with me because they admit they can
be wrong and us laypeople can be right.

 

[dxkj21]

Mythbusters opens their seasons with a Myth Revisited
show where they recheck themselves if viewers spot errors.
Veeerry unlike the big news media. Even though they do get
things wrong (the phosphorus as the paint on the nose
of an indendiary bullt [its a plug in the base of the bullet])
they have credibility with me because they admit they can
be wrong and us laypeople can be right.

but they were wrong on a revisit there, so now they need to revisit their revisit


They told us that the reason it caught on fire from further away is that the tip got to heat up lol

 

[Adept]

One thing to remember with the whole "getting knocked off your feet by a shot" thing: It doesn't take much to knock a person off balance, especially when caught by surprise. Also, the shock of the impact can be enough to throw someone off balance on it's own.

Added to that, the impact you feel against your shoulder from the recoil is not equal to the force the bullet impacts with. The weight of the weapon itself absorbs a lot of the force, and since the but of the weapon should be tucked in tight, there is no actual impact.

On topic: Mythbusters is an awesome show. Anyone else see the Chicken Cannon episode?

 

[Lupinus]

I found the gun knock back fishy as well.

And while off balance sure, maybe even light knock back. But flying across a room? Heck no unless it is from them stumbling back as a result of just getting a gut full of buckshot.

 

[Kurush]

from the recoil is not equal to the force the bullet impacts with

The force isn't equal, but the momentum is. Actually, the shooter gains a bit more momentum, because of the expelled gasses (super duper muzzle brakes notwithstanding)

 

[artherd]

Actually the shooter feels more due to the rocket-like effect of the hot gasses coming out of the barrel at 30,000psi *after* teh bullet has already been sent on it's merry way.

Anyway, getting knocked off balance or back 0.5" or so at the most is all that just about any shoulder-fired weapon will do to a person.

One thing to remember with the whole "getting knocked off your feet by a shot" thing: It doesn't take much to knock a person off balance, especially when caught by surprise. Also, the shock of the impact can be enough to throw someone off balance on it's own.

Added to that, the impact you feel against your shoulder from the recoil is not equal to the force the bullet impacts with. The weight of the weapon itself absorbs a lot of the force, and since the but of the weapon should be tucked in tight, there is no actual impact.

On topic: Mythbusters is an awesome show. Anyone else see the Chicken Cannon episode?

 

[Dragun]

.577 tyrannosaur being fired. 750gr bullet at 2400 fps. you can open it or download it. maybe this would knock a person off his feet. it did the shooter. pretty funny, http://www.filegone.com/vnj3

 

[Carl N. Brown]

If I got my physics right (no gaurantee):
The momentum (weight times velocity) is the opposite but equal reaction.

A 12 ga. slug weighs one ounce and has a velocity of 1600 ft/sec.
An 8 pound shotgun (128 ounces) would have a velocity of 1600/128 ft/sec
or about 14 ft/sec.*

Kinetic (impact) energy is mass times velocity times velocity (mv^2).
Kinetic energy of 1 ounce slug at 1600 ft/sec is 2480 foot/pounds.
Kinetic energy of 128 ounce shotgun at 13 ft/sec is 21 foot/pounds.
If the 1 ounce slug at 1600 ft/sec transfers all its energy with no
loss to a 180 pound Buster the Crash Test Dummy, Buster would have
rearward velocity of 0.55 feet/sec.

* I am calculating the ounce of slug only; to be accurate, I would have
to include the weight of the gas expelled from the barrel at 1600+ fps in
the calculation which would be a sizable part of the weight of the powder
charge: this would up the velocity and recoil energy of the shotgun
by a few percentage points.

 

[SDC]

Re: recovering bullets for forensic purposes...

When I'm firing a questioned firearm for samples, I fire it into a water tank that has about 6 feet of travel available before the bullet would hit the other end of the tank; the tank is angled downward so gravity will cause the bullet to roll downhill (into a basket for retrieval) once the water has stopped it, and most bullets will never get anywhere CLOSE to punching through the entire 6 feet of water (rifle or pistol). Most handgun rounds won't deform too badly in the tank, but some rifle rounds can be a real PITA to get decent samples from (mainly the centrefire "varmint" calibres; these have a tendency to come apart in the tank, leaving you with a handful of lead and copper scraps). For most centrefires, an ordinary "hunting"-style JSP (especially in a heavy bullet weight) will work just fine, though I'll usually have to cut some of the expanded material off the recovered bullet to look at the marks left on the bearing surface. Depending on the given gun/ammo combination, you can get very unusual or unexpected results; the last time I fired a Hi-Point Carbine for samples, 115-grain ammo simply would not grip the rifling, and they would strip straight through the bore. With 147-grain ammo, no problem.

 

[RecoilRob]

The weight of the powder charge is also involved in the recoil calculations and must be added to the projectile weight.

Even though it is responsible for the acceleration of the projo it too is taken from a dead stop to muzzle velocity when fired and so increases the recoil for the shooter vs. the remaining energy that the projo can deliver to the target.

 

[dhoomonyou]

The Girl with the Tattoos....

Scottie Chapman
from her bio: In addition, Scottie has played bass guitar for several underground punk/noise bands including the Wizards of Ozzie, a group that performed "lounge" covers of Black Sabbath songs. Plus, she can belly dance and fire dance — often at the same time.

Belly Dance & Fire Dance.
I love that show!!

 

[redneck2]

Mythbusters also did one where they determined you couldn't get shocked by pissing on an electric fence because there would be too many gaps of air in the stream of urine. My cousin told me about this episode when we came across an electric fence. To his horror, my cousin proved mythbusters wrong on this one, too. The wire was about 18 inches from the ground and he had a good stream going due to having a couple 40's in him. Not sure what the specifics were on Mythbusters.

I grew up on a dairy farm. TRUST ME. This isn't something you want to try at home

They are WRONG, WRONG, WRONG!!!

I suspect the thought of having lots of volts invading your private parts made the stream a little "erratic"