this post was submitted on 26 Jun 2024
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Mythbusters (mander.xyz)
submitted 5 months ago by [email protected] to c/[email protected]
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[–] [email protected] 3 points 5 months ago (1 children)

It isn’t that the water is stoping the bullet- rather that water’s surface tension creates a shockwave that shatters the bullet, and this distributes the mass over more fragments.

Lower power cartridges are able to survive that shockwave, or it fragments into fewer slugs which keeps its energy concentrated.

Either way, I wouldn’t want to be near the high powered cartridge hitting the water. You’re going to feel that shockwave.

[–] [email protected] 2 points 5 months ago (2 children)

It is the water breaking it. The water doesnt compress so the water doesnt absorb enough of the kinetic energy fast enough so the bullet fractures. As i understand it anyway. The 50cal is travelling a lot faster so a lot more force is applied on the bigger rounds.

Later on they did a dynamite fishing one and we learned being in water when a large enough shockwave hits is VERY bad for internal organs of squishy creatures in it

[–] [email protected] 2 points 5 months ago (1 children)

It’s the surface tension that causes the shockwave, soapy water wouldn’t have the same effect.

And yes, dynamite explosives are rather more dangerous under water. Which is how torpedos work to break ships without much regard for armor.

[–] [email protected] 1 points 5 months ago (1 children)

Right so its the water that causes it to break because of the surface tension of the water.

Sounds like you are arguing against my phrasing while agreeing with what i understand. Im confused why we seem to be in a disagreement.

Maybe you can school my dumb ass though, can you eli5 what would need to happen for you to say it was the water that does the work on stopping bullets?

[–] [email protected] 1 points 5 months ago

It’s the interaction between the air and water that does it.

If, hypothetically, you were to move something through the water at that speed, it wouldn’t shatter or just be stopped. There is significantly more drag, so it would come to rest sooner than in air but it wouldn’t just stop.

For example, many small boats have very high rpm propellers that survive just fine- until they start cavitating.

The reason a .50 cal or .308 shatter is the shock of hitting the surface tension, and it’s the shattering that allows the fragments to be slowed down so quickly.

It’s also the reason they were surprised- they forgot to include surface tension in their initial model.

[–] [email protected] 1 points 5 months ago

Dynamite in water is the same basic principle used for sea mines. History has taught us those actually work. With the bullet, it’s more about surface tension which makes sense as falling from a high enough cliff onto water if you don’t land right is nearly the same as falling onto concrete.

Cool stuff regardless and I always found their testing to be quite spot on, scientifically.