Does ice or water stop a bullet faster?

[Raggedyman]

Okay, yeah, ice IS water, but does liquid or solid water stop a bullet more quickly? Ice is less dense but obviously harder. We shoot .223 Rem Wolf 55 gr FMJ into jugs of ice and jugs of water to find out. Rifle is 11.5" bbl AR with a Surefire FA556AR.


Don't cheat. Post your prediction before you watch the video.


Link for phones that don't even.

[The_Shadow]

Very interesting...I would have thought the fracturing of the ice would lessen the stopping forces...May be because it was held tightly in the jugs it still applied force because it couldn't separate the chunks...

Thanks!

[Raggedyman]

I suppose that's possible. Maybe I should have cut the plastic away first.

[10mmfan]

I feel like velocity/caliber/projectile may vary which stops faster.

[Raggedyman]

There is a very good chance of that. I may perform this test again with 10mm 200 gr TMJ if there is enough interest in this video.

[my_old_glock]

Don't cheat. Post your prediction before you watch the video.

I say water will stop a bullet faster.


[ I just watched the video]

If both bullets/projectiles have the same mass and are traveling at the same velocity, they will both require the same amount of force to stop. The one that stops the fastest will have stopped in the shortest distance and seen the greatest impulse.

If two cars with the same mass are traveling at the same speed, and one hits a concrete wall while the other hits a giant block of Styrofoam. Both will have seen the same amount of force to stop, but one will have stopped in a shorter amount of time and distance. The car that hit the concrete will be severely damaged, while the car that hit the Styrofoam will have had almost no damage. The one with the less damage traveled the farthest.

If one bullet remained in one piece and the other disintegrated, I would figure that the disintegrated bullet stopped sooner.



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[Pinsnscrews]

Ice is compressable, water however, is not. Water /should/ impart more stopping force to the bullet than ice due to the fact that as water freezes, it expands, which is why Ice will compress when water will not.

I have not however looked at the video yet.

[gandog56]

I looked at it this way. If I was to drop feet first about 15 feet on ice or water, I would have chose the water. I would assume ice would have broke both my ankles. So I would have said ice was worse.

[my_old_glock]

The type of bullet may also make a difference. A hollow point can expand in water, but may not expand in ice.



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[sqlbullet]

Actually, water is compressible.  It's compressibility is very low, which is why it is commonly referred to as incompressible.  At 40 MPa water compresses about 1.8%.

This value does vary slighly based on temperature, and ice is less dense than water.  However, when compressed it readily reverts to a liquid, which is was makes ice so slippery.  Under pressure the bonds at the surface let go resulting in you standing on a liquid floating on a solid.

I predict little variation.  In fact, I predict that you would see different results over a variety of different temps of water.  I think you would probably see your best penetration around 45°, but I doubt you have equipment that is sensitive enough to meaningfully measure the differences unless huge sample sizes are used.

[Raggedyman]

Unsurprisingly, sqlbullet nails it.

[gandog56]

Yeah, but he makes poor Grog's head spin with scientific explanation! Me want go shoot bang bang now! 

[Ramjet]

depends on the bullet but I will go with water (by the way it's tough to predict and skip the responses but I did). Now hard cast I would say the ice HP water wins .. well let's go watch and see. So shoot a HP and tell me which works best.......interesting. I like this sort of experimentation. Good Stuff

[dakota1911]

More like how many 1 gal milk jugs filled with water can I shoot this high velocity rifle round through versus how many filled with ice?  Next time 12 gauge slug.  More impressive.

[bjw0007]

Water.  Mainly because the fracturing ice won't take as much energy as drag from moving through a liquid.  Now if it was Pycrete...