At what velocity will a bullet puncture flesh? A Helmet?

These questions are related to the indirect machine gun fire thread.

What is the minimum velocity at which a bullet will puncture a typical WW2-era tunic or field jacket and pierce the flesh?

What is the minimum velocity at which a bullet will puncture a WW2-era helmet?

I ask these questions because I would think that machine gun bullets fired in indirect mode would be traveling at a very low velocity by the time they fell into the "beaten zone."

 

These are very hard questions to answer; for instance, what bullet or what helmet, or even what cartridge are we talking about here? There are differences in all of those that would make results vary at long ranges. For instance: the 7.92X57 round had a longer, heavier bullet (for caliber) than the M2 ball 30-06 round and thus would have an advantage at long ranges. Also, the 7.7mm Japanese MG ammo differed from the rifle ammo making for differences even with the same nominal round. Therefore, there is no hard and fast answer to this question.

As a rule of thumb, the average full-power rifle cartridge used in WW2 is considered dangerous to at least 1.5 miles on straight flesh. I doubt there's been any penetration studies done at such long ranges but I might be wrong. However, one could simulate such long ranges by handloading cartridges down to say 500-600fps and seeing what they would do. Be sure to use FMJ bullets if you do.

 

I can't answer your exact question but this link will give you some interesting reading material on the subject Topic of the Month. In short this quote from the listed site adresses' the lethality of a falling bullet... "Based on the results of these tests it was concluded that the bullet return velocity was about 300 f.p.s. For the 150 gr. bullet this corresponds to an energy of 30 foot pounds. Earlier the Army had determined that, on the average, it required 60 foot pounds of energy to produce a disabling wound. Based on this information, a falling 150 gr. service bullet would not be lethal, although it could produce a serious wound."
If a .50 caliber machine gun was used for indirect fire it's bullet would have a striking energy of much higher than the minimum wounding level due to greater weight AND greater terminal velocity.

 

Only thing i know is that a .38 LWC is piercing flesh with a velocity of 228m/s. Don´t ask why i know this, but it is a proven fact. So depending on the bullet its speed and the ankle were it was shot, i would say that a normal MG ( .30 cal) not a .50 cal will penetrate flesh out to a distance of min. 1400m but that is a very rough estimate and not a scientific computation and to the helmet it is impossible to say it for the different shapes, the material and the ankle the bullet will hit it

 

Wouldn't the falling 50 caliber MG bullet have the same terminal velocity as the falling 150 grain rifle bullet?

 

If it will fall down to earth from a aircraft it propably will have it in theory, but with a huge load of powder behind it, it won´t. Except of the last meters of their way.

 

I might see if I can buy a surplus helmet cheap, put it on a melon, and take it out to the shooting range for some informal testing. I am a little nervous about loading a pistol round to really low velocities though. I don't want a bullet to lodge in the barrel, and I don"t want a bullet to ricochet off the helmet and come back at me !

 

Would be interesting to see what comes out. Depending on the helmet you use ( US or German WW2 rebuilds) use the backside to hit or one of the sides and shoot prone from 25yards from behind a sandbag if you use a pistol. That should be safe enough. With a rifle you can go out to 300 yards with FMJ ammo and it should go through it. Problem is only the point where the bullet will fall into subsonic speed, but you will be far away from this area no matter if you use a 9mm or a .30-06.

 

[video=youtube;gSIp22uaWrQ]http://www.youtube.com/watch?feature=endscreen&v=gSIp22uaWrQ[/video]

Here it is what happens with so called "Baby Calibers"!

 

Since we are talking rifle-caliber ammo here, I would suggest that you stay with FMJ rifle bullets, since pistol bullets are different weights, shape and construction and thus wouldn't be valid in a test. If you reload or know someone who does you could pull fmj bullets out of old suplus ammo and reload with low-power loads. However, this would be quite a project in terms of time and energy.

 

You might enjoy looking at this video from the time-period, and while it only deals with the US it is pretty interesting none the less even if it is obvious pro-American propaganda (3 parts).

Goto:

WWII Infantry Weapons and Their Effects, 1 of 3 - Real Military Videos

 

Either way you don't want to be inside a beaten zone of a machine gun!!!

 

Clint, that was the one i was looking for! Thanks for finding it.

 

If I get a little Christmas money this year, I will get a chronograph, a box of 30 caliber FMJ's and have a crack at a helmet.

That 17 HMR is am impressive little rimfire round, isn't it ?!

 

That little .17 is very similar to the 5mm Magnum Remington rimfire that lost out to the .22 Mag way back when. I had one of those Remington rifles, and it was a great little varmint shooter. The problem was that by the time I quit using it and sold if off, the shouldered rimfire rounds were more expensive than center fire .243 that I could reload.

That was the problem, it was a "one shot" round, just like the .22 Mag which it was similar to in spec., but it got very expensive per shot while the .22 Mag went down in cost and application. One of my little brothers even had a superb Winchester lever action in .22 Mag, and a well placed shot could take down a white tail deer udner 50 yards at no real cost "per round". The little/light weight "penta-point" 5mm Mag. couldn't do that to the reliability that I would shoot a game animal with the round.

It could reach "reach out and touch" a wood/rock chuck, or ground squirrel, or coyote at fine ranges.

 

It makes you realize how really powerful even standard big game cartridges are such as the 30-06. For the most part I fail to see the usefulness of "magnums" and their increased recoil. After all, many recruits in WW2 had problems managing the recoil of the Garand no matter how many times the sergeant fired it from his groin!

 

As an aside - someone asked if bullet penetration into through flesh has been studied...

Yes it has, exhaustively - but it's more in the realm of trauma and (particularly) forensic medicine

I've also seen a few tracts on combat medicine surgical and other techniques for dealing with/nursing bullet trauma and how they differed (considerably!) between the U.S. Army Medical Corps and the Wehrmacht...and they gave quite excellent detail on what various types and sizes of bullets do in flesh.

 

The tests have been done...as far back as the late 1800s...targets lined up at different ranges...most targets: Hesian, cardboard etc have a similar "consistency" to human skin...However...breaking the skin is not what you want from a bullet...you want it to penetrate the body...muscle, tissue etc to be effective so that its the penetration velocity you want to study...Pigs are good for that. A falling round will NOT penetrate, barely hurt your head...its momentum is weak as...but IF the bullet still has "basllistic energy" the the round IS still dangerous...problem is you have to fire the weapon almost straight up to ensure a full bleed of ballistic energy...if fired on an angle, the round may well still have some ballistic energy to peirce human skin (why we cant fire our weapons in suburbia) - Makes the fools on middle eatern tv as dumb as they look...The head of the round will to some extent also decide penetration power, its shape and make-up (hollow point for example)

 

I think I've posted up this statistic before on the forum - but in 1940 there were some 8,000 injuries/deaths caused to civilians in England during the Blitz by spent small-calibre AA munitions and larger-calibre shrapnel falling back to earth.