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View Full Version : Wanted Curve Bullet


Waingro
12-09-2007, 1:00 AM
Okay fellas, now I am sure many of you have seen the preview for the film Wanted - if not watch it here:

http://www.youtube.com/watch?v=O7ftozVc3lI

Now obviously no human could ever accomplish that task, taken the speed it would require to 'flick' the bullet would most likely make the gun jam (limp wristing it). Now I am curious about the physics in this. For all you guys will college degrees - would this be possible if somehow a human has enough speed and timing to pull it off? It does not seem out of the realm of possibility - yet it is obviously nothing that could ever be tested or accomplished due to human reaction times and speed.

So purely on paper - would this be possible taken the human element out of the equation and replacing it with Superman or the other superhero Flash (the fastest man on earth)

And that movie looks awful.

DedEye
12-09-2007, 1:20 AM
Looks like a Matrix clone.

bobfried
12-09-2007, 2:11 AM
Your question could only be answered with a yes. Considering I could put GOD in place of course it could be done. Heck I'm sure he/she can amek that bullet grow legs, run the Boston marathon, impregnate Hillary, organize a Bar Mitzhvah whislt it is curving around that piece of meat.

Now if we're talking real life I'm sure it can be done with some sort of special saboted projectile and some creative rifling. It won't be anything any mortal being can have any impact on, rather the result of purely mechanical and chemical reactions. There was talk for a long time of bullets with trajectory changing fins controlled by nanobots in flight. Or better yet, heat seeking ones.

TurboFall
12-09-2007, 5:31 AM
Assuming it's a regular bullet and the shooter doesn't have psychic powers to physically control the movement of the projectile, it'd be impossible. Once the bullet leaves the chamber, it's direction of free motion is already determined. Kind of like tying a ball to a rope, twirling it in a circle for a moment, then letting go. Even Superman wouldn't be able to accomplish that.

supersonic
12-09-2007, 6:04 AM
IS it JUST ME, or does the mere sight of this Hollywood trend of "guy flying sideways through air while shooting 2 pistols w/ precision & that same "look" on face" make anyone here want to F***ING VOMIT? I'd like to find the originator of the idea and just............grab & shake the A**HAT until his brains come out his ears & nose!!!!:(

Rob454
12-09-2007, 7:36 AM
IS it JUST ME, or does the mere sight of this Hollywood trend of "guy flying sideways through air while shooting 2 pistols w/ precision & that same "look" on face" make anyone here want to F***ING VOMIT? I'd like to find the originator of the idea and just............grab & shake the A**HAT until his brains come out his ears & nose!!!!:(

Wow tell us what you really feel. Dont hold back LOL
Yeah I know its a movie but I see guys at the range always trying the latest shooting stances they see in a movie. Pretty funny to see the bullets flying everywhere except at what they are actually aiming at.
I remember when lethal Weapon came out and Mel gibson was shooting that Beretta while he was rolling on the ground. i remember one guy trying that at a range. And getting kicked out. the other thing I remember was my buddy talking to me and ( a group of us) said hey you have a beretta ( looking at me) that takes 15 in the mag and one up the pipe. I smacked him across his head. I later sold my beretta to my buddy. he offered me 350$ more than I paid for the whole gun. I would be a fool not to sell it. i didnt care for the gun very much really. I got it as a present from my mom
Rob

VegasND
12-09-2007, 8:00 AM
Thanks for the trailer. I've added another movie to my 'do not see' list. I've only got so many hours left and to waste 2 of them on that would be wrong.

M. Sage
12-09-2007, 8:24 AM
Lol, barring some mechanical magic (round ball, curved barrel use the spin to throw a curve-ball), heck no.

I got a good laugh at the stories about boneheads trying to shoot the way they do in the movies.

scewper
12-09-2007, 8:25 AM
Assuming it's a regular bullet and the shooter doesn't have psychic powers to physically control the movement of the projectile, it'd be impossible. Once the bullet leaves the chamber, it's direction of free motion is already determined. Kind of like tying a ball to a rope, twirling it in a circle for a moment, then letting go. Even Superman wouldn't be able to accomplish that.

What he said.

wildcard
12-09-2007, 8:58 AM
Actually.. it's possible if you sidestep (or are sidestepping) at a very fast speed just as you fire the weapon. Think of what would happen (not relative to the vehicle) if you threw a tennis straight out of a moving vehicle. That tennis ball would continue moving forward while moving away from the car.

So to achieve what you saw in the video, the shooter had to either mover VERY fast, or the target was a few hundred yards away where then the shooter doesn't have to move as fast.

Try shooting a precision rifle from a moving vehicle at at target 600 yds away and you'll see what happens. Do it once while stationary.. then again while moving at even 5 FPS.. you'll be off by probably about 3ft.. which means you can actually curve around something that would otherwise have been in your way if shooting at it straight.

wildcard
12-09-2007, 9:04 AM
Assuming it's a regular bullet and the shooter doesn't have psychic powers to physically control the movement of the projectile, it'd be impossible. Once the bullet leaves the chamber, it's direction of free motion is already determined. Kind of like tying a ball to a rope, twirling it in a circle for a moment, then letting go. Even Superman wouldn't be able to accomplish that.

That's because the force vector is directed forward at a tangent to the circular path of motion. I don't even see how this applies to the question

tyrist
12-09-2007, 9:43 AM
NO current gun can fire it. I do think it is possible but would take a custom round with a custom gun. Would have to have similiar flight mechanics as a pitcher throwing a curve ball. Need to have a round bullet spinning like a baseball.

However would be almost impossible for a human being to aim it even if the flight path curved.

Army
12-09-2007, 10:14 AM
If the muzzle is moving sideways..not in a swing, but from right to left...the bullet will continue the sideways momentum that was put upon it, plus the normal forward motion from being fired. It is possible to for the bullet to strike behind an object, as long as the bullet was fired prior to a position directly in front of the object.

Any aerial gunner can tell you this.

Waingro
12-09-2007, 11:02 AM
so in theory it is possible.

slick_711
12-09-2007, 11:16 AM
Wow that trailer just made me lose so much respect for Morgan Freeman. And Jolie... well I never really respected her but now her stupidity detracts from her hotness. :p

The SoCal Gunner
12-09-2007, 11:16 AM
It's a movie based on a comic book guys, just like Spiderman and Batman. You don't watch it because it is realistic but for the entertainment purpose. Now if it were a movie based on reality, then I would expect the gun action to be realistic as well.

TurboFall
12-09-2007, 11:35 AM
That's because the force vector is directed forward at a tangent to the circular path of motion. I don't even see how this applies to the question

What i was trying to get at is that once the bullet exits the barrel and is moving strictly on it's own (as in without the barrel walls to direct it), the bullet's only going to move straight, or at least as straight as it normally goes. It's impossible to make the bullet change direction without applying a new force with the desired vector on it. Of course, you can apply a new force vector via a special asymmetric cavity or psychic powers, but a regular bullet won't change it's direction after it's been fired.

The ball analogy was just to make the point that when you let go of the ball and let it move on it's own, it'll travel straight and not curved, because it'll retain whatever direction vector you gave it just prior to letting go, not any of that spinning you did to it beforehand.

I guess it'd be possible to move the gun in a sideways direction to impart a diagonal motion to your bullet, but then you'd just have a diagonally-traveling bullet, not a curved one. So you'd still have to move your gun "around" the piece of meat, since the bullet trajectory will still be linear.

savasyn
12-09-2007, 11:40 AM
IS it JUST ME, or does the mere sight of this Hollywood trend of "guy flying sideways through air while shooting 2 pistols w/ precision & that same "look" on face" make anyone here want to F***ING VOMIT? I'd like to find the originator of the idea and just............grab & shake the A**HAT until his brains come out his ears & nose!!!!:(

I think you might be looking for John Woo. It isn't a Woo movie unless that happens a couple of times. In slow motion. With doves flying in the background.

JagerTroop
12-09-2007, 11:41 AM
the only way this would be possible is to have a spherical projectile that would only grip the left or right side of the barrel (depending on which way you would want the bullet to curve). Think of that old toy "trackball"Here's what I'm talkin about (http://cgi.ebay.com/WHAMO-TRACK-TRAC-BALL-TOY-TRACBALL-OUTDOOR-BALL-GAME_W0QQitemZ320131764327QQihZ011QQcategoryZ19017 QQcmdZViewItem). Do any of you remember it? It was very similar to Jai Alai Look Here (http://en.wikipedia.org/wiki/Jai_alai). By puting a spin on the spherical projectile, you could induce a curve effect, also similar to a pitcher's curve ball in baseball. Obviously this would be VERY unreliable/unpredictable from a marksman's standpoint, but it IS physically possible.

TurboFall
12-09-2007, 11:45 AM
the only way this would be possible is to have a spherical projectile that would only grip the left or right side of the barrel (depending on which way you would want the bullet to curve). Think of that old toy "trackball". Do any of you remember it? It was very similar to Jai Alai Look Here (http://en.wikipedia.org/wiki/Jai_alai). By puting a spin on the spherical projectile, you could induce a curve effect, also similar to a pitcher's curve ball in baseball. Obviously this would be VERY unreliable/unpredictable from a marksman's standpoint, but it IS physically possible.

Then it would be the design of the bullet and not the wielder. He'd never be able to shoot straight with those bullets from thereon out :rolleyes:

JagerTroop
12-09-2007, 11:49 AM
If the muzzle is moving sideways..not in a swing, but from right to left...the bullet will continue the sideways momentum that was put upon it, plus the normal forward motion from being fired. It is possible to for the bullet to strike behind an object, as long as the bullet was fired prior to a position directly in front of the object.

Any aerial gunner can tell you this.
This is true, however, the bullet isn't curving. The trajectory is still a straight line. It only gives the illusion of a "curving bullet" because your perspective has changed. The path of the bullet from point A (leaving the muzzle) to point B (target) is a straight line, regardless of the bullet strafing. You're just compensating for latteral movement (leading), not making the bullet curve.

JagerTroop
12-09-2007, 11:50 AM
Then it would be the design of the bullet and not the wielder. He'd never be able to shoot straight with those bullets from thereon out :rolleyes:

Absolutely correct. You'd have to employ two barrels... one for curves, and one for straight shots.

TurboFall
12-09-2007, 11:53 AM
Absolutely correct. You'd have to employ two barrels... one for curves, and one for straight shots.

Yeah, I was referring to the trailer. You see Morgan Freeman make the shot with what I'm guessing is a normal pistol and ammunition, implying he does it with some pseudo-mystical intuition :)

JagerTroop
12-09-2007, 11:59 AM
Yeah, I was referring to the trailer. You see Morgan Freeman make the shot with what I'm guessing is a normal pistol and ammunition, implying he does it with some pseudo-mystical intuition :)


Yeah, someone stated it very well when they said it was like the Matrix

M. Sage
12-09-2007, 12:13 PM
so in theory it is possible.

It is possible to for the bullet to strike behind an object, as long as the bullet was fired prior to a position directly in front of the object.

No, not the way they showed it. The above means that as long as there was nothing in the bullet's path when you fired, the bullet could hit a target that was "behind cover" at the time of impact. It's the same as swinging that slab of meat to the side, then quickly back into line of fire after the bullet goes by, and that ain't what they showed. :p A bullet is still going to move in a straight-ish line, and even if a round of .45 were tumbling, it's not going to change the trajectory very much over that short of a distance. Not enough to notice, probably.

4 Brigada
12-09-2007, 1:35 PM
Sorry after Angelina , was there something else on the trailer?:D

Use The Force Luke

dw1784
12-09-2007, 5:08 PM
That's because the force vector is directed forward at a tangent to the circular path of motion
angular momentum. See gyroscope.
so in theory it is possible.
if the projectile is stabilized using controlled flight(unlike the traditional grooved barrel) it might be possible. The challenge would be packaging and control.

yaw can be induced given a known setting. The easiest is laminar flow disruptors, either by surface geometry or external appendages. Yaw rate control is the next challenge. Given such a small projectile payload and close proximity to the target, unless switching and sensor technology has shrunken to atomic level, it's not likely to happen.

with a large enough payload and switching/control speed, I can see a projectile using flow disruptors for controlled flight to within target range and detonate using a proximity sensor and kill by fragmentation.:)

What Just Happened?
12-09-2007, 8:28 PM
Can a bullet travel in the path indicated in the movie trailer shown? Yes.

In fact, a projectile traveling that type of parabolic path has already been done and is being done. It's done in paintball and in Airsoft all the time.

All you have to do is induce a spin about an axis that is not about the axis of travel. if you play tennis it would be equivalent to topspin, bottomspin, or sidespin.

This is achieved in paintball or airsoft (where there is a spherical projectile) by having a lip or a surface of the barrel on one portion of the barrel that will make contact with the projectile. Because this surface makes contact with the projectile, friction will cause rotation in the projectile. This rotation, via a simple bernoulli's equation, will cause lift.

Do note that in paintball and airsoft, a spherical projectile is used. Also, this is not feasible in a traditional firearm, for the following reasons;

Paintballs do not travel over 300 fps (due to safety regulations) and airsoft pellets travel around 400 fps. That is a drastic difference against the 1000 fps a 9mm travels at or 3000 fps that rifle rounds travel at. This would cause severe leading or copper fouling.

The barrel could not be rifled, it would now have to have a series of ridges down the barrel. This would make the effective range and accuracy equal to or less than that of a smoothbore longarm.

You would need a sphere projectile and sphere projectiles are inherently inefficient. They have more drag and can't be used in conjunction with rifling. Also, your accuracy with such a firearm would be dreadful.

In order to get this effect, one side of the barrel would have to be in more firm contact with the projectile and would have to allow some gases to escape via the non-contacting edge. This decreases your effectiveness with the firearm two-fold. One, much of the gases are escaping rather than propelling your projectile. Second, the unequal amount of gases escaping around the bullet would equate to a a compensator being installed upsidedown. You would get more muzzle-flip.

This effect is used in paintball because of the limitation on the exiting velocity of the projectile. The limit is only on the linear velocity, not on the total energy present in the projectile. This effect is generally used to create lift so the paintball has a longer effective range. This longer effective range is about 150 feet. Yes, feet. Without it, your range is about 100 feet. Serious Tournament players don't use it because of two reasons. One, it's terribly inefficient with their propulsion. Paintball uses compressed gas and their current tanks hold enough power for about 1500 rounds. That may sound like a lot, but you need to go see a game. They'll carry about 1000 rounds onto the field and in a serious round, they'll use most of that. They cannot afford to reduce the amount of ammunition they carry onto the field at a given time. Second, the tournament fields are designed such that you will not need the extended range.

Airsoft on the other hand can use this effect simply because the amount of energy used to propel an airsoft pellet is much less. An airsoft pellet is about 6.2 grains vs. a paintball which is about 60 grains.

Hope all this stuff helps and answers your question.

M. Sage
12-09-2007, 10:25 PM
The paintball barrels that induce spin, the ones that work anyway, use a gentle curve and a loose bore, so that the paintball rides along the outside of the bore and comes out with a backspin.

Trajectory is flatter, but the range isn't a whole lot greater. It's a lot easier to aim consistently at the edges of that range, but I've shamed Flatline shooters with standard barrels enough to know that their performance is deceptive.

At the end of the Flatline's effective range, it seems like the paintball runs out of energy all at once. It doesn't just taper off, it suddenly falls to the ground, like a wing in stall (which might be what's happening.)

What Just Happened?
12-09-2007, 11:36 PM
Well, yes. The barrel-to-paint match is the most important thing in paintball accuracy. Else the paintball is just bouncing down the barrel. With the proper match, all of the gas is used to propel the ball down the barrel, hopefully, in a straight line.

Stall occurs when a wing is at an angle where it can no longer provide the necessary lift needed to keep the weight aloft. I wonder if it has something to do with the change in the stagnation point due to the rotation of the paintball or the fact that the rotation causes the velocity of the air beneath the paintball to be much higher than the 300 fps the paintball itself is traveling at.

kap
12-10-2007, 8:21 AM
Cool scene, but not possible with any gun. This is what people have come up with so far to get around curves with bullets.

http://www.secondworldwarhistory.com/imgs/stg44c.jpg
http://kalashnikov.guns.ru/images/1741.gif

I am sure it could be done given the correctly engineered firearm. Like others have said, making a bullet curve like that would require an off axis spin on the bullet like a baseball pitcher induces on a curve ball. It would likely require a round projectile and a specifically engineered barrel though. Then the problem would having the target at the specific distance required to hit it. I vote for just shooting through the hunk of meat.

bigthaiboy
12-10-2007, 1:19 PM
Cool scene, but not possible with any gun. This is what people have come up with so far to get around curves with bullets.

http://www.secondworldwarhistory.com/imgs/stg44c.jpg
http://kalashnikov.guns.ru/images/1741.gif

I am sure it could be done given the correctly engineered firearm. Like others have said, making a bullet curve like that would require an off axis spin on the bullet like a baseball pitcher induces on a curve ball. It would likely require a round projectile and a specifically engineered barrel though. Then the problem would having the target at the specific distance required to hit it. I vote for just shooting through the hunk of meat.


And here's a bullet I designed and precision manufactured utilising the latest tools currently available (well, in my garage anyway), to use with the rifles above.
I call it the "BOOMerang". Catchy name, huh? ;)

6456

Currently only available in 8mm.

StraightShooter
12-10-2007, 7:35 PM
And here's a bullet I designed and precision manufactured utilising the latest tools currently available (well, in my garage anyway), to use with the rifles above.
I call it the "BOOMerang". Catchy name, huh? ;)

6456

Currently only available in 8mm.


Ill take a thousand!

Grouch
12-10-2007, 7:50 PM
Looks like a Matrix clone.

not really.

psriley
12-10-2007, 10:53 PM
Couldn't be done as shown in the animation, as others have noted. It might be possible if the projectile could be induced into a flat tumble upon exiting the barrel, and one side of that round were scalloped. It would be similar to a boomerang. However the path of the projectile would describe an arc, not a diversion.

Besides, I think it's far more interesting that the Last King of Scotland is now an action hero.

M. Sage
12-11-2007, 4:58 AM
Well, yes. The barrel-to-paint match is the most important thing in paintball accuracy. Else the paintball is just bouncing down the barrel. With the proper match, all of the gas is used to propel the ball down the barrel, hopefully, in a straight line.

Stall occurs when a wing is at an angle where it can no longer provide the necessary lift needed to keep the weight aloft. I wonder if it has something to do with the change in the stagnation point due to the rotation of the paintball or the fact that the rotation causes the velocity of the air beneath the paintball to be much higher than the 300 fps the paintball itself is traveling at.

I've always wondered if they were losing their spin because of drag or something.

What Just Happened?
12-11-2007, 5:10 AM
Besides, I think it's far more interesting that the Last King of Scotland is now an action hero.

Wha? How is the Last King of Scotland an action hero? Or even a hero for that matter?

I've always wondered if they were losing their spin because of drag or something.

They will lose the rotational speed due to drag, but that shouldn't make them suddenly drop off. It should only make them go back into the parabolic arc they would normally travel in.

psriley
12-11-2007, 8:54 AM
Wha? How is the Last King of Scotland an action hero? Or even a hero for that matter?

The actor in the trailer is the same actor who co-starred in "The Last King of Scotland". But you're right, since Wanted appears to be his first action film, it's probably too soon to call him an "action hero". Maybe "action hero apprentice".

What Just Happened?
12-11-2007, 8:46 PM
Oh, I thought you meant the character, not the actor.

NeoWeird
12-11-2007, 8:59 PM
I don't know what you guys are talking about, I do that all the time at the range....just turned 90 degrees....:rolleyes: