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Author Topic: Bullet spins like top on ice...  (Read 7435 times)

Shootist

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Re: Bullet spins like top on ice...
« Reply #15 on: January 11, 2015, 10:15:34 PM »

It makes sense that a bullet slows quickly in water but ice is a solid. Why does the bullet not penetrate in ice like it does in wood? I would think the ice would crack. How thick does the ice have to be to not crack? If you shoot bullets at concrete the bullet deforms and flattens, why not with ice?
Shootest????????????????????????????????

Dick,  Disclaimer: I live in Alabama and the only ice I see is in my glass of sweet tea. ???? While I have trained & shot many weapons during the course of my career, I have never shot into ice.

I have watched the videos on YouTube involving the spinning bullets on ice. The bullets in the video are a "Full Metal Jacket Bullet". A round nose smooth hard copper encased lead core bullet. This bullet will not deform as easy as a "Jacketed Hollow Point Bullet" made for self defense.

I think Ta0 is correct when he states that the bullet is skipping off the ice. Here's my opinion why.

Coefficient or Friction also know as Drag Factor: A bullet shot at a concrete wall will most likely deform due to the drag factor of the concrete wall material being more course than ice. A Full Metal Jacket Bullet with it's smooth round nose and the ice being a smooth and slick surface has a lower drag factor. This lower drag factor would cause the bullet to skip on the ice. There is not enough friction on the ice to grab the bullet long enough to cause it to deform on impact.

Subsonic Ammunition is another way to help prevent over penetration into the ice.
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the Earl of Whirl

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Re: Bullet spins like top on ice...
« Reply #16 on: January 11, 2015, 10:57:49 PM »

Isn't there more ice up in Canada, Jack?  Either that or Shootist could make a visit to a local ice rink >:D
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Happiness runs in a circular motion!

the Earl of Whirl

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Re: Bullet spins like top on ice...
« Reply #17 on: February 07, 2015, 10:26:58 AM »

Ha ha!  "Outrageous Acts of Science" is a TV show on the Science channel.  I happened to turn it on and watched it for a bit.  They did a countdown of the top 20.  Guess what was number 11?  Bullets spinning on ice!!!  The guy didn't just shoot one bullet in the ice and go look for it.  He shot a bunch and then went looking. 
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Jack

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Re: Bullet spins like top on ice...
« Reply #18 on: February 07, 2015, 07:07:01 PM »

Isn't there more ice up in Canada, Jack?  Either that or Shootist could make a visit to a local ice rink >:D

oh i just noticed this, u bet theres pleanty of ice, one might be well advised not to shoot the hockey rink here unless a lynching is what your after  ;)

Ha ha!  "Outrageous Acts of Science" is a TV show on the Science channel.  I happened to turn it on and watched it for a bit.  They did a countdown of the top 20.  Guess what was number 11?  Bullets spinning on ice!!!  The guy didn't just shoot one bullet in the ice and go look for it.  He shot a bunch and then went looking. 

that does it im going out to accost one of the local gangbangers and pester him till he gives me his pea-shooter, be back soon with results of tests @-@
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ta0

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Re: Bullet spins like top on ice...
« Reply #19 on: February 08, 2015, 10:42:57 AM »

I could not find that video but there are many other cool videos on the Outrageous Acts of Science website.

Shootist and family: when are you starting a top using bullets? >:D



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ta0

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Re: Bullet spins like top on ice...
« Reply #20 on: February 08, 2015, 02:08:47 PM »

Shootist and family: when are you starting a top using bullets? >:D

I looked a little more into this.
I found on Wikipedia that a 0.22 LR bullet (apparently the most commonly sold) has a nozzle velocity of 533 m/s, a mass of 2 gr. and typically spins at 78,750 RPM

One way of spinning a top with a bullet would be to hit it in the perimeter so the momentum of the bullet creates the torque to spin it.
A little bit calculation gives me that in the best case, for the bullet being lodged at the rim of a small top (i.e. a Gladiator), it could make it spin at around 10,000 RPM. So it is theoretically possible, but my guess probably quite difficult, to spin a regular top with a bullet. However, a special target spintop could be designed for this.

Another way to spin a top would be to transfer the rotation of the bullet to the top. I get that the rotational inertia of the bullet is about 100 times less than that of a small top. So, if the bullet was shot down through the crown and became lodged inside the top, to conserve the angular momentum you have to divide its rotation by 100. The Gladiator would spin at less than 800 RPM: not enough but close. A faster spinning bullet could theoretically do it. According to the rifling article on Wikipedia, a bullet from a M16A2 rifle can spin at 314,000 RPM, what would give about 3,000 RPM for the top. In practice, however, you would need to stuff the top with something heavy to stop the bullet, what would increase its inertia, so it may not work after all . . .

« Last Edit: February 08, 2015, 02:10:59 PM by ta0 »
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mailman

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Re: Bullet spins like top on ice...
« Reply #21 on: February 09, 2015, 02:37:29 PM »

I'm not sure there is anything you could stuff a top with that would be able to absorb the energy of a .223 round from an M16 rifle.  Their penetrating power is formidable....
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Turegano

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spin top gun real bullet dancing
« Reply #22 on: February 12, 2018, 03:40:13 PM »

Note admin: I merged with the above topic, but not sure if that was the subject of this post.
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hello everyone I was surprised to see her dance as a spin top

hola a todos  me sorprendio verla bailar como spin
« Last Edit: February 12, 2018, 11:29:30 PM by ta0 »
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TROMPO MEXICO

TheSpinForce

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Re: Bullet spins like top on ice...
« Reply #23 on: February 21, 2018, 10:39:55 AM »

This is pretty cool, who would've known
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Turegano

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Re: Bullet spins like top on ice...
« Reply #24 on: February 25, 2018, 10:24:32 AM »

thank you very much for moving my comment to this I did not know how to do it I wanted to upload the video but nopude and I think someone had already done it but thank you very much it is incredible to see the bullet dancing greetings
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