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For the Ballistically Inclined

2015/10/02

Why aren’t bullets sharp?

First,

They don’t have to be.  Bullets go 1,700 miles per hour.  Humans are soft.

Blunt bullet tips do more damage.  They brute-force their way into the skin and essentially rip a hole through the victim.  Pointed-bullets do less damage and are used for thick-skinned prey or armor-piercing.  The aerodynamic form also makes them better for long range rifles. @Clayburn

Next,

Ah…you have touched on a subject that has been a bone of contention for nearly as long as man has used firearms.

Firearms evolved before aerodynamics were understood.  Hence the first projectiles were crudely shaped rocks then round masses of lead.  They did the job, although the were inaccurate.  It was not until the rifled musket came along that bullets obtained their characteristic aerodynamic shape.

The Minie’ ball (old habits die hard) was the first widely used bullet to have the somewhat pointed shape and was used in our Civil War.

The Minie’ ball was also of soft lead but its advantage was the hollow base expanded to the rifling in the bore and increased accuracy five fold.  Aimed fire could now be delivered out to 500 yards instead of the 100 yard maximum capable with a smooth bore musket.

Now fast forward to about WWI.  Bullets had advanced from paper cartridges to metallic cartridges and more aerodynamic bullets.  The old .30 inch, or .30 caliber Kraig Jorgenson rifle, standard issue to the army in the Spanish American War was being phased out in favor of a newer more modern copy of the Mauser rifle used against the Kraig in Cuba.

This rifle was the Springfield Model 1903.  Douglas MacArthur was the Army Chief of Staff, at the time of its introduction.  It was going to be introduced in a smaller caliber than the .30 caliber of the Kraig.  MacArthur insisted that the army adopt a .30 round based on the 1906 model cartridge.  The round was hence known as the .30-06 the first truly pointed bullet used by US military arms.  The French had been using them since the 1890’s and most of Europe had followed suit.  Instead of a 220 grain round nose bullet, the .30-06 was designed with a 150 grain bullet giving it a 500 ft per second advantage over the 2,300 ft/s round nose version.

The problem with that was the 150 grain bullet loses velocity faster due to it light weight, although it fires flatter and faster at first.  This led to problems in WWI with our opposition being able to out range our machine guns that fired .30-60 ammunition.  Changes were made and the projectile weight was increased to 174 grains and the base of the bullet was tapered into what is described as a “boat tail”.  This reduces aerodynamic turbulence at the base of the bullet, resulting in suction which slows the bullet.  If you have ever had a station wagon or vehicle with a flat ass end, you will notice how road dirt collects there due to an eddy that forms in its wake.  The solution to that was putting a deflector on the roof to deflect an air stream downward to keep the rear window clean.

The changes resulted in 2,640 ft/s velocity and a range of 5,500 yards.     This was too unsafe for military ranges so the bullet was dumbed down by a change of powder, return to a 150 grain bullet with a flat base.  It gave a “safer” 3450 yard maximum range.

The cartridge changes resulted in their being a bit more cartridge than necessary, in other words the case was bigger than needed, resulting in US soldiers having to carry a lot of extra brass for no good purpose.

https://s-media-cache-ak0.pinimg.com/originals/69/df/6b/69df6b4d42e47b8e90c31de906439001.jpg

Ammo and Gun Collector: A comparison of rifle ammunition Calibers used in WWI & WWII

The size of the 30-06 can be seen in the lineup above.  The 30-06 is at far left, followed by the  German Mauser 8mm, Russian 7.62, and the Italian 6.5x.52, cartridges not shown are the British .303, the AK-47 7.62×39 and the NATO 5.56.

https://upload.wikimedia.org/wikipedia/commons/9/9d/8x57.jpg

Spitzer bullet – 1888 pattern M/88 (left) alongside the 1903 pattern 7.92×57mm Mauser   (designated as the 8mm Mauser) S Patrone.

The lower picture shows the 8mm Mauser  and 30-06 rounds with a Sptizer Boat Tailed FMJ bullets used in WWII.  The one in the top picture shows a round nosed and soft tip hunting bullets that were not used by the Military.

The 30-06 was our mainstay cartridge for both WWI, WWII and Korea.  After Korea we standardized on the NATO 5.56 cartridge along with all NATO members (third from right).

With the advent of assault rifles the US went looking for a new battle rifle and the debate over what size and shape projectile should be used.  Another round of tests copying those prior to WWI were run and without MacArthur around to overrule the findings, the Army decided to go with the .223 inch/caliber round.

Many pigs gave their lives for these tests, as there is a reason cannibals refer to people as “long pigs”.  Anatomically pig cadavers offer the best test subjects for ballistic tests this side of actually using people.

So many a pig cadaver were ventilated to validate the fact that at battle field distances, the .223 did just fine in snuffing out two legged life forms.

Now there were a number of things that factored into the decision.

Weight of cartridge:  The 30-06 was large and bulky the .223 was small and so a trooper could carry more ammunition into battle at the same weight as before.  A trooper could carry a basic load of over 200 rounds at nearly the same weight as the combat load of 100 rounds of 30-06.  This does not include extra bandoliers but just basic two belt ammo pouches of the standard web gear.

An interesting note, is the web gear issued was designed for use with the M14 7,.62 caliber combat rifle and not the M16 .223 caliber rifle.  Mad for the large M14 magazines the ammo pouches were too deep for the smaller 20 round M16 magazines so troopers had to stuff the bottom of the pouches to be able to easily reach the smaller magazines.

Ballistics:  Bullets are nothing if not all about causing wounds. It was discovered that boat tailed bullets are marginally stable, which is a good thing when it comes to causing wounds.  As soon as the bullet hits something, it destabilizes and begins to tumble.  So that puny .223 inch bullet that hits you suddenly turns into a tumbling .5 inch buzz saw ripping through you as it bounces around.

Back in the day when war was seemingly fought by rules it was determined by the European powers that bullets should be humane, so now hollow point, soft point, or other modified or enhanced bullets were to be used.  Fold lore has it that during the Sepoy Rebellion in India in the late 1800’s that bullets were modified at the Dum Dum arsenal by removing part of the .303 bullet jacket to reveal the soft core.  This enhanced the mushrooming effect of the bullet.  Mushrooming can be seen on the far left in the first picture of the Minie ball.  So in effect we were modifying projectiles to do what the big hunks of lead we shot at each other for he proceeding 300 years.

Dum-dums

Dum-dum use, 1914

M88 form

M88 form

However these were now deemed as inhumane.

The image below shows the difference of a would between a FMJ, full metal jacket, boat tail Spitzer bullet on the left and a all lead Minie’ ball, Dum Dum or, expanding or tumbling bullet on the right.

https://qph.ec.quoracdn.net/main-qimg-5f7bf266166c2ec1f97bd4949a8148ca

 One under stands why amputation was the normal way of dealing with a limb hit by one of the latter bullets before reconstructive orthopedics became advanced.

Now, the Army is nothing if not slow to adapt.  They fought wars using out dated tactics when fire arms had made quantum leaps.  In the Civil War they still stood in close grouped masses when guns were not 5 times as accurate with imaginable results.  Even in WWI they charged in close formations into the hail of bullets hosing at them from machine guns.

So it is not unexpected that ballistics and the finer points of projectiles did not sink in for some time.  The whole reason bullets became pointy was not for better penetration, brute force does that pretty well.  It was all about aerodynamics and range.

A case in point.  In WWI when German snipers were using armor plates with loopholes from which to shoot from behind, the Brits had no armor piercing ammunition with which to defeat them.  The pointy .303 bullets ricocheted off.  So some fellows brought in their blunt nosed safari express elephant guns and let go with good results.  Other blokes pulled bullets from the .303 and reversed the bullets blunt base first and found they punched through the armor plate in that configuration.

Now it came to be that the Allied soldiers would kill any German sniper they caught because they thought the Boche (Beasts) were using doctored or altered bullets.  The Dum Dum seemed to raise its ugly head again.

See: German forbidden bullets, 1914

The truth of the matter was they were not.  A sniper does anything BUT tamper with his ammunition as it effects accuracy.  He goes so far as to not shoot any bullet except from the same manufacturing lot, babying, polishing and hoarding his ammunition like a Lioness with her cubs.

What caused the misunderstanding was the observed effects of a high velocity bullet on a human head.  If you have ever watched the Zapruder film of President Kennedy’s head exploding from the 6.5 mm bullet hitting it you will know what I mean.  The 6.5 mm bullet was blunt nose FMJ bullet by the way.

You have seen a milk jug being hit by a bullet it explodes due to the hydraulic pressure wave caused by the sudden release of several thousand foot pounds of energy inside the sealed container as the bullet hits it and slows down.

The same thing happens when the sealed container called the human skull is hit by a high velocity bullet.

The British Tommys assumed that the devastating results were due to doctored bullets.  They were not.

Today, most hunting bullets are “doctored”.  A lot of time and money have gone into perfecting bullets that expand in a controlled fashion and not suddenly disintegrate.  By the same token, you do not want to use Full Metal Jacket bullets either.

My late uncle went deer hunting using surplus FMJ ammo and swore he shot a deer four times only to have it run off.  It is no wonder.  The FMJ bullets just zipped through the deer, probably fatally wounding it, but not before it ran into the next county. If he hit its heart, or shoulder or other wise incapacitated it.  It would have dropped but FMJ bullets are designed to penetrate people but also are expected to penetrate brick, wood (about 30 inches of wood, kind of makes hiding behind a 1 inch thick table in the movies kind of silly) anything else you can think of.

Hunting bullets are designed to create that hydraulic shock wave by creating a big wound channel and at the same time delivering all the ballistic energy they can.  Hunters do not want the bullet to exit the target if it does, that means it did not dump all its energy into the target animal.

In fact Hollywood gets it wrong most of the time. When a person or animal is hit by a bullet, the bullet keeps going, and the victim drops, they do not dance around or jerk like a puppet on a string.  That was started and invented by the 1960’s movie Bonnie and Clyde.  A living target does not jerk or fly into walls or out windows unless a bone is hit and even then it is likely the bullet just keeps going and the person drops.

In Audie Murphy’s book about his time in WWII called “From Hell and Back” he writes of a squad mate in Italy running and being hit by a MG42 8mm round that severs his shin bone.  The guy is in full stride and it causes a compound fracture and the guy keeps running on the stump of the bone sticking out of his leg.  So in effect the bullet chopped of his lower leg and it did not slow him down.  They did not put that particular scene in the movie.

So hunting bullets pointy or not, are designed to expand to 2 or 3 times their starting diameter, an create a huge temporary would channel and in so doing transfer all the ballistic energy to the target causing that hydraulic shock wave that helps to incapacitate and kill the target.

Pointy bullets are simply for aerodynamics.

Keith Patton

See Also

Tools: Ballistic Calculator
5.56x45mm Versus 7.62x39mm

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