"MythBusters Guns and Water" Topic

I just saw the MythBusters episode where they shot rounds into a swimming pool and determined that high velocity rounds would not penetrate a person at about the depth of 3 feet if shot at a 23 to 30 degree angle.

I know their tests are fun but not always wholly scientific. Meaning, I won't be dodging bullets under water anytime soon.

My question is as follows: If the MythBuster's finding are valid, does that mean that the opening scene in Saving Private Ryan was pure Hollywood? Specifically the scene where soldiers were shot while underwater. As, SPR seemed to be a relatively well researched movie I assume that the underwater scene was a result of WWII vet testimonials. Perhaps somebody remembered his platoon mates being hit while underwater?

Yet the findings of the Mythbuster's seem to negate this "underwater" death scene. Perhaps the rounds lost enough velocity by the time they traveled across the beach and hit the water so that they penetrated the water as opposed to disintegrating on contact.

Does anybody have any opinions on the subject?

Water stops bullets pretty fast. A simple method of obtaining fired bullet samples is shooting into a barrel of water (standard 55 gallon drum or similar).

Someone I know did this with his swimming pool (not at a person, just shot into the pool and dived to retrieve the bullets).

I don't recall the scene exactly, but unless the men were very close to surface, the bullets would have been pretty ineffective.

Perhaps the effect that Speilberg wanted was to convey to the audience that the landing beaches were not nice places to be. As soon as that ramp went down (if not earlier) nowhere was safe. Once in the water a minor bullet wound would cause shock, panic and a sense of forboding – accompany that with all the weight in your pack, weapon and ammunition you begin to loose control and drown but the blood still flows out for a while.

When crime scene techs are comparing bullet markings. they use water to shoot the bullets into. The water stops the bullets very quickly and does not damage the bullets. Thus they can compare barrel markings to determine which gun the bullet matches.

Didn't more men drown because they were too heavy with all their equipment than from bullet wounds while in the sea?

I think Speilberg used that scene for effect (successfully too!)

I love the MythBusters show – I would like to have their job!!!

Gav

Love Mythbusters, but I have to scratch my head sometimes about their techniques. Let's not forget that they ain't shooting those rounds from HMGs, and the power behind those so-and-so's is nothing to be sneezed at whilst underwater. Nope, I'm not about to endorse portable swimming pools as bullet-proof armour anytime soon. And yes, a terrible number of US soldiers did drown on the beaches, pulled under by the weight of their kit, and through being dropped off the LSTs far too soon. The US Marine Corps, apparently, spent a lot of their time bashing their heads against the Army's brick wall, trying to tell the GI's bosses to send the first waves ashore with as little on their back as possible, but nobody would listen. You'd think the army would've learned to listen to guys who had 'been there – done that', but…

I don't want their job, but that Kari, on the other hand… ;)

While I too would hesitate to try it out personally, their test using no less than a Barett .50 caliber sniper rifle was rather convincing.

Yeah, but those Mythbuster apprentices (the lackies they get to make stuff) are complete tools, the ammont of dopey mistakes they make is painful. I still cringe when I see the pretty auburn haired one flashing that microwave gun they made out of an oven in her own face, WHILE IT WAS ON! DUH!

It was a short exposure, but still pretty daft.

Matsu, definitely agree with you about Kari. :P

However, they did fire a 50 cal into the pool, had a massive rifle to fire it too.

They found that the larger bullets tended to disintegrate soon after they hit the water. However, they didn't get it to hit the target so they couldn't gauge whether a such a large calibre would be able to penetrate deeper into water.

Caliber-wise, MG42 ain't no HMG. The round has power compareable to common hunting calibers. It is soon stopped in water…

…assuming it doesn't richochet off the surface due to shallow entry angle (seen that done)!

Any WWII veterans about the place, to put us amatuer speculators out of our misery? I mean, have any of us been shot at whilst underwater??

I've read accounts of WWII UDT swimmers watching and hearing the Japanese MG bullets pattering the surface above them, but doing no harm. I'd cite book and author if I could remember.

10 years ago I would have grabbed the physics textbook and started calculating hydrodynamic resistance.

5 years ago I might have posted a Thomas Paine quote.

Today, I'm just too damn tired…

SPR is not at all accurate in many places. Don't even get me going on that. I used to get calls and emails from guys working on it ever day in frustation of "guess what stupid thing they want to do now!"

And the shooting guys underwater is pure Hollywood.

Something I thought of while watching Mythbusters(other than how long will it be before one of the rounds fired at the pool ricochets off the surface of the water and sails through window at the end of the building), was what type of ammunition were they using? Their gun "expert" said they were using FMJ, but if the bullets were disintegrating like they did, they must have been using lead core ammo. I wonder if they would have gotten the same effect if the ammunition had been steel core, like most military rounds.

Still, it was pretty inspiring to see Jamie fire the .50 BMG into the pool….

-Michael

So these guys fired how many rounds?

Would you not think that in all the rounds fired on the beach that day it's entirely possible to have had one bullet go through the water and kill a guy already heading to the bottom? But as has been pointed out before I don't actually know anything.

The sound of the bullets going through the water in SPR was cool.

PJ

It looked cool, but was typical hollywood bunk.

Another factor the Mythbusters discovered but did not elaborate on was the higher muzzle velocity rounds disintegrated quickly while the lower velocity rounds, shotgun, pistol and muzzle loader penetrated better. Since the Atlantic wall was not a couple of feet from the water surface, the rounds would have slowed down before hitting the water by the landing crafts.

Now, the shotgun with the deer slug penetrated 8' of water, the ballistic gel and shattered the tank of water they had built. Straight down instead of an angle but was still impressive.

So a deer, hiding at the bottom of my pool behind a block of ballistic gel is only kidding himself if he thinks he's safe!

That is good to know. :-)

SeattleGamer wrote: "So a deer, hiding at the bottom of my pool behind a block of ballistic gel is only kidding himself if he thinks he's safe! That is good to know. :-)"

Sometimes deer hunters scare me…

Hah!

I don't know any deer hunters. I know a few lazy louts who sit in trees and wait for the deer to come to them but they don't really hunt.

The 9mm penetrated at 8' first.

The funny thing is the muzzle loader didn't do any worse then the .223, .30, or .50. The M-1 slightly penetrated the gel at 10" under and at the angle( total 2' of water). It would have meant a painful skin break maybe but not more.

It appears to have everything to do with muzzle velocity. Remember, all shots were fired within a few feet of the water. So the bullet impacted the water at it's theoretically highest possible velocity. The higher velocity bullets (2500fps+) shattered on impact with the water. The musket and shotgun with Mvs of 1000fps passed through 8' of water before doing serious damage to the gel.

So, in Saving Private Ryan, we can assume that if the range from the MG-42s to their targets was long enough, the velocity of the rounds may have dropped off sufficiently to prevent the bullets from shattering.

So, in fact, Mythbusters might actually support that sequence in Private Ryan as being possible.

This is why ballistics experts use a water tank to stop rounds in a short distance when they have to test fire them for things like checking barrel groove marks.

Please people, do not take hollywood as valid historical fact. If you have been around productions (as I have been) you would be dumbfounded as to why and how decisions are made, and just what the so called "experts" actually know.

I was thinking that the shotgun slug caused the tank to shatter due to cavitation? A large mass such as a solid slug in an mostly enclosed area of water could cause such pressure to be exerted onto the tank walls by the water displacment.

Must accounts have veterans saying they remember soldier being hit while "in the water" never stoping to say if floating, swimming or diving. I guess that the soldiers "in the water" who were no draged underwater and drowned had managed to inflate their "life savers" and were hit while floating.

I've read accounts of WWII UDT swimmers watching and hearing the Japanese MG bullets pattering the surface above them, but doing no harm. I'd cite book and author if I could remember.

I can confirm reading this book, but can't cite it either.

There's more to that story, too: experienced frogmen used to catch bullets with their hands for souvenirs. I remember six feet being the magic distance.

Similarly, if you're putting bullet to target on the other side of glass (even plain residential stuff): shoot twice. Once to break the window and once to make contact. Glass can cause quite a bit of deflection — it's pretty amazing.

Was it 3' depth, or 3' total travel distance in the water? Theres a big difference at a 23 degree angle.

I would really want a wider series of tests to decide how deep is safe. A machine gun at 300 – 500 yards is a lot different than a sniper rifle at 10 feet. Just the turbulence from a large number of shots may dramatically change how subsequent shots behave. An armor piercing round is probably going to be different from a lead or FMJ round.

Also, a "skin break" in water, especially sea water, is a nearly unquenchable wound for anyone without the training and equipment to deal with it in the water.

I believe the germans often turned anti-aircraft guns into anti personnel guns, too.

Mythbusters does some cool stuff, but a lot of it isn't definitive. Its almost scientific, but they don't do a lot of controls or cover all the situations they need to – its not good television to do all that stuff.

It was 3' total distance under water(or less). The .50 fired at 23 degrees to a depth of 14". The M-1 target was only 10" under and through about 2' of water. For some un-explainable reason, I wrote those two down on a pad next to my PC.

So, in Saving Private Ryan, we can assume that if the range from the MG-42s to their targets was long enough, the velocity of the rounds may have dropped off sufficiently to prevent the bullets from shattering.

One thing though. If the round had already slowed enough to not shatter on impact with the water's surface, it would take even less distance through water to stop it.

The two physical factors that are most important here are momentum & inertia And drag coeficient (which would be modified by bullet shape dynamics.)

The slug may have had an advantage the other bullets didn't depending on the shape of its nose. If one looks at the supersonic torpedoes the Russians have they are designed with blunt noses – you would think they have more drag but they cause a special low-presure space around most of the body of the missile allowing it to drastically reduce drag and achieve nearly the speed of sound underwater.

"One thing though. If the round had already slowed enough to not shatter on impact with the water's surface, it would take even less distance through water to stop it."

Not neccessarily. The lower velocity rounds used in the test (<1000fps) were passing though up to 8' of water and causing "fatal" wounds on the gel, while the high velocity rounds were shattering almost on impact with the water. If the MG-42 rounds in Private Ryan had traveled far enough that their velocity had bled off to less than 1000fps then it's possible that they too might have been able to penetrate 8' of water and still have enough energy to cause serious wounds to a person.

I think the scene in the movie is quite possible.

I find it facinating that you guys are dismissing a reasonably scientific finding because you saw the contrary in a movie.

I saw Arnold fire a M-60 with one hand, so that means that every soldier can do it, right?

reasonably scientific? Putting a high-velocity rifle a few feet from water means that the results can only be applied to rifles a few feet from water.

Unless there were German Machinegunners standing a few feet from the water, I don't think their experiment proves or disproves anything.