[Skillet]

so the kickoff of the new mythbusters season is on tonight on the Discovery channel. you should watch it because they are showing some bullet myths!

mythbusters has done good to the Gun community over the years, so they have become my favorite show.

thats all!

[GonHuntin]

Hope they find better "experts".......I watched an episode earlier today when they were shooting vehicle gas tanks to see if they would explode like in the movies. It didn't work, so they decided to use tracers........they explained how the orange color (paint) on the nose of military tracer ammo actually contained phosphorous and was ignited by friction with the air as the bullet flew to the target.....they even used an animation of how this supposedly works...what a load of crap!

In 2 minutes, they could have googled it and found out that tracer bullets actually have the tracer compound loaded into the heel of the bullet and that the color on the nose of the bullet is marking paint used to identify the ammo as tracer, incendiary etc......

Funny, but I saw no "trace" from the tracer ammo they were using............

[highorder]

Funny, but I saw no "trace" from the tracer ammo they were using............

Yeah, they were firing from 30 yards or so. Most tracers dont ignite that close to the muzzle.

[GonHuntin]

They moved the target out farther at the end..........by the way, tracers are ignited by the powder charge while still in the barrel......they may not burn brightly right away, but they do ignite while still in the barrel.........the downrange ignition theory is a myth.......there is nothing in the tracer compound that would cause it to ignite downrange.

They are fun to play with when conditions allow their safe use..........shot some out of a suppressed 300 whisper......low enough velocity to really enjoy watching the trace.

They also claimed to be shooting incendiary ammo which definitely produces a visible flash when it strikes a metal object.........did you see any flashes???

[Sunray]

"...tracers are ignited by the powder charge..." Nope. The trace element, a phosphous compound, ignites when it contacts air. Long after the bullet has left the barrel.
Neither one of those two Mythbusters guys should touch a firearm. They know nothing about them. Jamie's claim to expertise is having grown up on a farm.

[GonHuntin]

The trace element, a phosphous compound, ignites when it contacts air. Long after the bullet has left the barrel.


BS!

You apparently have never loaded your own ammo or pulled the bullet on a loaded cartridge........I can assure you, air is present in the loaded cartridge!

I have used tracer ammo and have handled tracer bullets (not cartridges, bullets) in the open air.........The compound that burns in a tracer bullet is ignited by the powder burning in the barrel.......do some research!

From International Forensic Science and Investigation Series........Chemical Analysis of Firearms, Ammunition, and Gunshot Residue By James Smyth Wallace

http://books.google.com/books?id=dHbHS5GhCN4C&pg=PA72&img=1&zoom=3&hl=en&ots=x0Ntmx-lM0&sig=ACfU3U21gfQeKaft99VD_1pj1P6tDq6uoA&w=800

http://books.google.com/books?id=dHbHS5GhCN4C&pg=PA73&img=1&zoom=3&hl=en&ots=x0Ntmx-lM0&sig=ACfU3U19ew3jTPSR6lwx_qkVShmis36U_w&w=800

[nitetrane98]

Quote:
The trace element, a phosphous compound, ignites when it contacts air. Long after the bullet has left the barrel.


BS!

+1^
They also become lighter as they burn and exhibit slightly different ballistics than the other FMJ's in the mix when fire FA.

[9teenEleven]

jeez, tough crowd here.

[fireman 9731]

I am still not convinced that a bullet dropped at the same time as one fired will hit the ground at the same time...

I plugged in some numbers to PointBlank ballistics software and things didn't add up... I dunno... Physics is physics but there are a lot a variables....

[JohnKSa]

I like it that they are willing to do work involving firearms, I'm less happy with the fact that they often promulgate incorrect information by failing to do their research.

The falling bullet "myth" is one that they really messed up badly. They never recovered any rifle bullets so they (incorrectly) assumed that rifle bullets would be tumbling on the return trip like the pistol bullets they recovered. Sometimes rifle bullets (particularly those on the heavy side for a particular caliber) tumble on the fall back to earth but Hatcher proved years ago that some remain stabilized and fall base first. That will make a huge difference in terminal velocity--the bullets will fall much faster if they remain stabilized.

Basically their testing was completely invalid because they made an incorrect assumption and did their testing with a terminal velocity that was much too low.

[mljdeckard]

What they did tonight was amusing, if unsurprising. The tested to see if a dropped bullet hits the ground at the same time as a bullet fired horizontally from the same height. Most of us already know that this is true, but like everything they do, the fun is watching them figure out how to test it. they had some trouble getting a device to drop at the same time the bullet leaves the barrel. I found myself wondering if they had consulted some of the better manufacturers or bullet suppliers, they would probably find that they are always set up to run similar tests, and could have told them how to make it a lot easier. Oh well. Like say, the fun is watching them figure it out.

[Erik M]

I really liked the detail they put into the bullet drop test. i wouldnt mind having a monstrous indoor space like that to shoot in.


Carrie is pregnant. My nerd side feels sad, almost betrayed.

[fireman 9731]

Carrie is pregnant. My nerd side feels sad, almost betrayed.

Haha, yes, mine too. I googled it and it turns out that she had her baby back in June.

[hammerklavier]

Hit the ground at the same time? You would have to drop the bullet from the same height as the maximum height the bullet reaches in its flight path at the same time it reaches that point, not when it is fired. And there are still more variables involved than that.

[jay gatz]

"
Hit the ground at the same time? You would have to drop the bullet from the same height as the maximum height the bullet reaches in its flight path at the same time it reaches that point, not when it is fired. And there are still more variables involved than that.
"

That's why you fire it level, so that the bullet starts out at its maximum height. The only variable between the Mythbusters test and pure physics is wind resistance and minute differences in measuring heights as they were only using a tape measure and not some highly sophisticated and accurate/precise equipment.

Mythbusters is a great show for entertainment value, but they lack a lot of scientific ability and rigor, not to mention research. At the beginning of every show they parade their years of experience in special effects, not science and research. As such they can make things look cool, but aren't always on the mark.

[nwilliams]

Carrie is pregnant. My nerd side feels sad, almost betrayed.

You mean Kari :neener:

Mythbusters is such a great show, never missed an episode since season one and I think that was about seven years ago.

It's good that they are kicking off there new season with myths involving guns. I've always felt that this is one of the most pro-gun shows on tv.

Neither one of those two Mythbusters guys should touch a firearm. They know nothing about them. Jamie's claim to expertise is having grown up on a farm.

I have to disagree. While they may not be gun experts they never claim to be and they always seem to treat guns with a healthy level of respect. They might do stupid things with guns from time to time but they seem to take plenty of safety precautions when they do.

[freakshow10mm]

The gun stuff is mostly stuff that has already been proven or disproved.

[DougDubya]

The gun stuff is mostly stuff that has already been proven or disproved.
Not for the general audience.

I also found it interesting the effects of close range shots into the water at an angle does to bullets less than the size and mass of a .50 BMG on the "deflect angle of bullets by diving into a pond" myth from a few years back.

Handgun rounds didn't disintegrate, but the rifle rounds did.

[kw11b2p]

The Bullet myth is assuming a perfect vacuum. The law of physics states that, due to gravity, horizontal velocity does not affect verticle velocity. Therefore, in a perfect vacuum, any two objects, regardless of mass, will fall at the same rate. This is true until Earth's atmosphere (not a vacuum) is taken into account. A bullet leaves the barrel and begins to fly "down range" and actually rises slightly due to the "lift force" created by atmosphere before beginning to fall......This is the same reason that in the military we change our point of aim for exact targets that are very close. I'm sure that there will be many posts contradicting me, but physics doesn't lie.

[JohnKSa]

A bullet leaves the barrel and begins to fly "down range" and actually rises slightly due to the "lift force" created by atmosphere before beginning to fall......It is possible to get lift force on a bullet under certain cross-wind conditions as a result of the Magnus effect but I do not believe that is what is causing the effect you're talking about.

The reason the bullet appears to rise early in the trajectory is because the barrel is pointed slightly upwards in relation to the sights. If the barrel weren't pointed upwards you'd never be able to hit anything more than a short distance from the muzzle.physics doesn't lie.That is correct. However it is not uncommon to find people who think physics is lying when it is not or think that what they observe is proof of something that it is not.This is the same reason that in the military we change our point of aim for exact targets that are very close.The reason you change your point of aim for exact targets that are very close is that the bullet starts out lower than the sights since the muzzle is lower than the sights. So one must aim higher than they wish to hit when aiming at very close targets.

http://www.frfrogspad.com/traj.gif
http://www.rifleshootermag.com/shooting_tips/ballistics_0303/
http://www.deerhuntersclub.com/long-range-shooting/bullet-flight-and-hunting-optics/
http://www.hornady.com/ballistics/external.php
http://www.exteriorballistics.com/ebexplained/5th/50.cfm

[kw11b2p]

As I stated, I knew people would question my explanation for the difference in drop time. That being said, my primary purpose was to say the "myth" that any two objects, regardless of horizontal velocity, when dropped will touch ground at the same time is based on a law of physics contingent upon the presence of a Perfect Vacuum, devoid of atmosphere, aka friction. Therefore it is impossible to prove this using the fired bullet example until a perfect vacuum that could contain such a test exists. Therefore, horizontal velocity, due to atmosphere, does in fact affect the rate of fall and will therefore make it near impossible to accurately "bust the myth". In closing, the LAW of physics being tested, cannot be tested or busted accurately, in this manner, because the state of nature required for the law to be tested does not exist in testable conditions.

[Deckard]

I saw they were going to test the "wanted myth" and changed the channel. No experiment required. I did wonder why they had to fire the .50 via string instead of just pulling the trigger.

[natman]

Hit the ground at the same time? You would have to drop the bullet from the same height as the maximum height the bullet reaches in its flight path at the same time it reaches that point, not when it is fired. And there are still more variables involved than that.
Dropping the bullet from the same height as the fired bullet's maximum wouldn't be hard because the fired bullet never gets higher than the muzzle (assuming the bore is horizontal).

Any "rise" in a fired bullet's path is relative to line of sight, not the muzzle.

[JohnKSa]

Any "rise" in a fired bullet's path is relative to line of sight, not the muzzle.Unless, of course, the muzzle is pointed upward. Then the bullet rises relative to both. ;)Proven rightWell, don't get used to it... :D As I stated, I knew people would question my explanation for the difference in drop time.Let me guess. You're so sure you're right that you didn't even bother to click on any of the four explanatory articles I provided...:DTherefore, horizontal velocity, due to atmosphere, does in fact affect the rate of fall and will therefore make it near impossible to accurately "bust the myth".No, horizontal velocity will not affect the rate of fall. Unless the Magnus effect comes into play (which would either require a typical spin-stabilized bullet AND a crosswind or it would require a round projectile with forward spin or backspin) the fired projectile will not experience a vertical force due to the presence of air since it is not shaped properly to provide lift.That being said, my primary purpose was to say the "myth" that any two objects, regardless of horizontal velocity, when dropped will touch ground at the same time is based on a law of physics contingent upon the presence of a Perfect Vacuum, devoid of atmosphere, aka friction.In that case your primary purpose was to say something that is incorrect in two respects.

First of all, the presence of a PERFECT vacuum is not necessary to test this. Real world vacuums have been very effectively used to demonstrate that even two very dissimilar (in terms of weight, shape and size) objects will fall at the same rate in the absence of drag.

Secondly, it's not necessary in this case to do the test in a vacuum because the two objects are identical and will therefore, as they fall, experience identical drag, aka friction, due to their fall. That means that the test can be done in the presence of air without fear that it will affect the results.In closing, the LAW of physics being tested, cannot be tested or busted accurately, in this manner, because the state of nature required for the law to be tested does not exist in testable conditions.That is simply not correct.

There is no law of physics that says the horizontal velocity of a bullet affects the rate of fall. If you believe otherwise I invite you to cite that law.

[PandaBearBG]

Alot of those bullet myths may have already been studied or proven, but mostly proven in a crappy chart and or spreadsheet or long winded article. Seeing it done is much more entertaining. I think they pull the trigger with a string to eliminate human influence or outside factors that may jerk the trigger that may influence the flight. The show if fun, I'd rather see 2 semi amatuer experts do over the top experiments than just read about them. Even if they know that it wont work, like the Wanted myth, it's still fun.

[LaEscopeta]

Carrie is pregnant. My nerd side feels sad, almost betrayed.Haha, yes, mine too. I googled it and it turns out that she had her baby back in June.

I tuned in late, and was wondering if Kari was pregnant or had just let herself go. In the 3 “knock-your-socks-off” bits she seemed to big, a little smaller, then bigger again. I assume they put the show together in a different order than it was filmed.

And I got my wife to watch (even the firearms parts) because she wanted to figure out if Kari was pregnant or not.

You will now be returned to you regularly scheduled firearms thread….

[natman]

As I stated, I knew people would question my explanation for the difference in drop time. That being said, my primary purpose was to say the "myth" that any two objects, regardless of horizontal velocity, when dropped will touch ground at the same time is based on a law of physics contingent upon the presence of a Perfect Vacuum, devoid of atmosphere, aka friction. Therefore it is impossible to prove this using the fired bullet example until a perfect vacuum that could contain such a test exists. Therefore, horizontal velocity, due to atmosphere, does in fact affect the rate of fall and will therefore make it near impossible to accurately "bust the myth". In closing, the LAW of physics being tested, cannot be tested or busted accurately, in this manner, because the state of nature required for the law to be tested does not exist in testable conditions.
What difference does air friction make? Same bullet, same gravity. Sure, air friction has a huge effect on the left to right component of the bullet's path, but the up and down component is the same.

[youngda9]

A bullet fired horizontal from a gun will not hit ground at the same time a bullet dropped from the same height will.

A bullet fired from a gun does not continue to pint horizontal to the ground. As it falls, the nose tips downward and the bullet accelerates somewhat towards the ground because the velocity vector is no longer horizontal to the ground. Read Jim Carmichael's book of the gun, it is explained in detail.

Mess around with a ballistics calculator program and it can be understood. http://www.handloads.com/calc/

[HGUNHNTR]

Can someone explain this new variable gravity thing, Im confused:confused:

[LaEscopeta]

What difference does air friction make? Same bullet, same gravity. Sure, air friction has a huge effect on the left to right component of the bullet's path, but the up and down component is the same. The fast moving bullet fired from the pistol creates turbulent flow as in moves through the air. That is air molecules are pushed out of the way of the bullet sudden enough and fast enough to cause them to move in random paths.

The dropped bullet is moving slowly, and air moves around it with laminar flow. That is the air molecules move is smooth, roughly parallel paths around the bullet, coming together again on the back side of the bullet.

Air resistance is greater for turbulent flow than laminar flow, and this greater air resistance acts in all directions, including the up and down component. That is once the air is disturbed enough to go turbulent, it creates a zone of turbulent air all around the moving bullet, that the bullet has to go through on the way down, at greater resistance. Same bullet, same gravity, but greater air resistance for the fired bullet, so the fired bullet falls down slower.

Having said that, the difference in air resistance would be small over the 3 vertical feet drop height of the bullets in the Myth Buster’s test. Their dropped bullet hit the ground 0.03-something seconds before the fired bullet. Maybe this is the result of different air resistance, maybe it is the in-accuracy of their test procedure/equipment/measurement ability.

[LaEscopeta]

Can someone explain this new variable gravity thing, Im confused.Newton’s answer: Gravity varies with the inverse square of the distance between the centers of mass of the objects experiencing the gravity.

Einstein’s answer: An object falling through a gravitational field experiences variable gravity directly proportional to the difference in the object’s acceleration and the local gravitational constant. An object near the earth’s surface falling and accelerating at 32.2 Ft.sec per second experiences no gravity. An object falling at 16.1 ft/sec per second experiences ½ the gravitational force as an object that is not falling.

http://en.wikipedia.org/wiki/Gravitation

(I know, you knew that already, and this wasn’t the variation being referred to.)

You will now be returned to you regularly scheduled firearm related thread…

[eye5600]

They could have saved themselves a lot of trouble by consulting a good ballistics calculation program. It would have told them at the range at which the .45 would hit the ground, for example. The fun of the program is actually testing things full size, which is unusual in this age of computer calculations.

I think the point about the effects of the atmosphere is a good one. If the bullets were to drop very far, it would have a big effect, and the effect at 1000 ft/sec is very different from 0 ft/sec.

[CoRoMo]

Is it yet viewable anywhere on the net?

[mljdeckard]

eye5600 -I think there is under some circumstances, a SLIGHT difference. Not a big difference.

In the grander scheme, imagine a B-17 firing a .50 cal horizontally, with a bullet being dropped at the same time. In between trying to factor lift from the forward motion, whether the gun is perfectly level or aimed up or down a bit, for all intents and purposes, the fired bullets and the dropped bullets are going to hit the ground pretty much at the same time.

[eye5600]

In the grander scheme, imagine a B-17 firing a .50 cal horizontally, with a bullet being dropped at the same time.

When I said a big difference, I meant a big difference between in the atmosphere and in a vacuum, not between the two bullets. A bullet dropped from a great height would get to the ground faster in a vacuum.

I agree with LaEscopeta that the air flow around the two bullets is very different, so it may have a big effect on the way the bullet falls.

[ny32182]

A vaccume is only needed if two dissimilar objects are subject to the test. (i.e. dropping a hammer and a feather on the moon). Since the bullets are physically identical, the only differences in air resistance that will affect the test are the orientation as they fall: The fired bullet will always have its nose forward, while the dropped bullet will tumble. This will cause *very* small variations in the vertical wind resistance component, but not enough to be independently measurable under the other constraints of the test: low vertical velocity, ruler-measured starting height, etc.

Also, the bullets are concentric, not shaped like an airplane wing, so there is no lift as they travel horizonally... like someone said, the bullet appears to "rise" relative to the line of sight; it does not actually rise unless the muzzle was pointed up. In the Mythbuster test, they fired the bullet with the muzzle laser measured at perfectly horizontal, so the bullet is at its highest point the instant it leaves the barrel.

I believe they did the best they could with the equipment they had, it was a valid test, and their results bore that out. Their observed variation in ground impact time is probably small enough to be attributed to whatever imperfection existed between the hight of the muzzle and the height of the dropped bullet/imperfections in the floor/imperfections in their exact release timing... overall it was very, very close.

[C-grunt]

Some of you guys are no fun. Jesus people its a tv show not a bunch of NASA scientists writing a report. Are there going to be inconsistencies in their findings.... of course. Its a show for entertainment not pure scientific discovery.

[Erik M]

If Mythbusters really wanted to satisfy the firearm community they would need to have some "armchair gunfighters" from Thr, AR15, firing line, ect. . . to tell them about how physic's and quantum mechanics really work.

[DougDubya]

If Mythbusters really wanted to satisfy the firearm community they would need to have some "armchair gunfighters" from Thr, AR15, firing line, ect. . . to tell them about how physic's and quantum mechanics really work.
LMBFBO!*

(Laughing my big fat butt off)

It's funny because it's true.

[UnclePete]

Mythbusters is great. It shows people who are not homicidal maniacs taking a healthy interest in guns, and what other show does that?

[dom1104]

I love how people critique misinformation on a tv show, and there is enough emphatically stated drivel re: tracers in this very thread lol.


"NO, I think tracers ignite based on some sort of electromagnetic charge given off by friction of water particulate....."

[mm1ut1]

Now if a tracer is fired horizontally...........:D

[Cycler]

Dum question - what's in the bullet they were holding with the electromagnet that made it magnetic? Was it the shape of the jacket?

[GonHuntin]

Didn't see it, but it probably had a steel core or copper washed steel jacket.

[CleverNickname]

I'm surprised no one else mentioned their second NFA violation, with their electrically powered trigger activator on the 1911 they were using in the test.

[LaEscopeta]

I'm surprised no one else mentioned their second NFA violation, with their electrically powered trigger activator on the 1911 they were using in the test.If the trigger activator has to be reset by hand bteween shots, I don't think it would by in voilation of NFA.

[Skillet]

while Mythbusters does get some things wrong with things like that involving guns and ammo sometimes, at least they are a popular TV show that looks at guns and (when in a safe environment of handling guns) portrays fun, unlike NBC who looks at guns and portrays a homocidal maniac with dual AK-47's shooting up everything in sight, and that whoever owns a gun is just like that maniac.

thats a good job in my eyes.

[ChaoSS]

I'm surprised no one else mentioned their second NFA violation, with their electrically powered trigger activator on the 1911 they were using in the test.Likely they have a bunch of lawyers checking with the ATF and local authorities on everything. Many things have an exemption for tv purposes though, and I'm sure they got any licenses they needed for it.

[Samilitant]

If the measured difference between the two was .03 seconds, then who cares what hits first? It's close enough to say they hit at the same time. That's my take.

[lbmii]

To the bullets can fly crowd. Um if there is any discrepancy in the time between when a horizontal fired verses dropped bullet hits the ground then it is due to the inaccuracies of the experiment.

So the gods of gravity give fired bullets a special pass?

[KJS]

I saw the falling vs fired bullet hitting the ground at the same time test. They had considerable difficulty getting the dropped bullet to fall at exactly the same time the gun was fired.

Obviously they used a .45 ACP because they wanted a slow, heavy bullet that was going to hit the ground within the confines of a large building. I think it took 360 feet for it drop 3 feet and hit the ground.