The myth part is that the bullets are designed to be non-lethalish – they aren’t. They are designed to be as lethal as possible given the restrictions in place (no hollowpoints, which is a kind of outdated notion).
Secondly, during a firefight, soldiers aren’t going to stop shooting to take people “off the field”, unless they are medics, in which case they aren’t generally doing a ton of shooting anyway.
The posts made so far have got me thinking about what would be the process involved if I wanted to make a new weapon/bullet; how would I go about it, and what would be the process?
I freely admit that I know nothing at all about bullet or weapon design, so all I have to offer is my beer and peanuts thinking.
In designing a new rifle/ammo, my first consideration would be a lethal range and accuracy specification. For example, I would specify 100% kill at 500 yards, with a 6 inch group.
The kill specification would require that a specific energy be delivered on target by the impacting bullet. Energy delivered is a function of mass and velocity.
So, to kill the target, the bullet must have a minimum velocity of V1 and mass of M1.
Accuracy is determined by the bullet’s velocity, mass, and its rate of rotation about its longitudinal axis; the rate of rotation is a function of the rifling and the length of the barrel.
However, in order to impart the original spin, and maintain in flight stability, it seems that there would be a minimum length for the bullet; say L1.
The practical maximum length of a squad weapon barrel is say L2 inches, and there is a corresponding upper limit to its weight, say W1 lbs.
So, we have a bullet of length L1, a barrel of length L2 and barrel maximum weight W1.
The specific propellant to be used in the cartridges would be capable of producing a maximum pressure of P1 per unit weight. This, and the barrel specifications, would put an upper limit on the total propellant charge of the cartridge.
Given the design envelope for the barrel, all of these considerations would put a lower limit on barrel wall thickness, and a consequent maximum on the bore diameter, call it Bd.
So, at this point, we have bullet length L1, a barrel length of L2, a barrel weight of W1, and a maximum bore diameter Bd.
We then construct a bullet out of normal materials (copper, lead and zinc) of length L1, diameter Bd and weight X; “X” would be a function of L1 and Bd.
Then, using the maximum propellant charge, we conduct a field test of the barrel and cartridge combination; and measure the impact energy, and accuracy, delivered on target at the specified range.
If the delivered energy is more than required by the specification we can cut back on the propellant. If the energy is insufficient, then we can cut back on the diameter of the bullet.
If the accuracy is off, then we can modify either the length of the bullet, or the barrel rifling.
So, starting with the original kill specification, we can modify the propellant charge, the bullet diameter, or the bullet length in order to meet the spec.
By this process, we end up with a bullet caliber that meets the kill specification; but does not necessarily correspond to any “logical” numerical value.
This line of thinking may explain why we have such odd bullet calibers; the bullet caliber is the result of a process directed at meeting a specification.
My cite above indicates that at least two versions of the 5.56 NATO will tumble if it passes through 4-5 inches of soft tissue, and if it has sufficient velocity it may fragment within the target. My cite may well be wrong but I’d like to see a counter-cite.
Wounding certainly will remove more men from the field but that’s not the reason why the switch was made from 7.62 NATO to 5.56 NATO. Remember 7.62 NATO is basically 30.06 with its case shortened - a hunting round suitable for pretty big game, shot at long range with a bolt-action rifle. 5.56 is simply a more appropriate cartridge for the battlefield.
My cite above also states that the tendency for the M16A1 and M16A2 to tumble and fragment within a target wasn’t discovered or understood during development, and so wasn’t intentional.
And to expand that, the French used .69 caliber musket balls because it was the size of a common lead ball of a particular weight – .69 caliber corresponds to 14.5 balls/pound. That was the reason behind most odd-seeming musket calibers. The weight of bullet, combined with some optimum geometry, probably accounts for some of the original caliber decisions for a given cartridge.
[quote=“ivn1188, post:10, topic:551851”]
Why is it that nobody ever thinks in terms of letting the poor grunts carry the same number of rounds in a lighter load? 
Yes, that’s the point I’m making – no one decided to make “tumbling” bullets, and there’s no rationale that more people are removed from the battlefield if you wound instead of kill.
Also, most rounds will act strangely in the body, especially when they hit bone. It’s not intentional, though.
I’m not sure that you are correct in this.
I recollect reading, a long time ago, the book “The Great Rifle Controversy” by Clinton Ezell, in which he explicitly explains that the prototype of the M16 was specifically rifled to provide the bullet with the bare minimum of spin.
The reason for this was explicitly to provide an unstable bullet which would tumble on contact, thereby causing greater wound damage. It was this specific attribute that made the prototypes such a favorite with the Special Forces testers in the field.
Furthermore, the effectiveness of this was proven by the reaction of the VC: the VC would go out of their way to capture a prototype M16 (it wasn’t called that at the time; I forget what its designation was then).
However, once the heavily modified production version was issued to troops in the field, the VC left them on the field. They considered them an inferior weapon.
Which doesn’t make much sense. Less spin on a bullet only limits the range and accuracy, and doesn’t have much of anything to do with wounding capability.
The weapon you are thinking of is the Armalite AR-15, which had a 1 in 14 twist (and sometimes even longer because of manufacturing issues), but the light bullets and slow twist meant the bullets would sometimes tumble in the air, especially when cold, and suffered very heavily from brush deflection. Both utterly destroyed accuracy when they happened.
There were indeed reports of horrific wounds, but no one, even using original parts and ammo, has ever reproduced the “tumbling buzzsaw wound” effect. And given that your average vietcong was wearing very thin clothing and weighed about 100 lbs, wounds tended to be more spectacular-looking than expected.
Here’s one article explaining it
Another about the physics involved
The fact is that the belief that the 5.56 was designed to tumble (in air or in a body), and that this was to remove extra men from the field than an outright kill is an urban legend that has been disproven many times, but contains just enough truth to make it seem plausible (namely that almost all rounds will yaw when they hit, and that the bullets are made to fragment to increase lethality since we can’t use expanding bullets).
There was no intentional tumbling designed into the round, and almost all rounds will deflect inside the body.
Ah…
Now it strikes me that when you and Stranger stated that a 5.56 doesn’t “tumble”, you meant end over end repeatedly. Fair enough. Substitute “yaw through 90 degrees” for “tumble” in my posts and we’ll all be happy!
As ivn1188’s rather good cites explain, the forces on a bullet passing through tissue are much larger than any stability conferred by the rifling spin. To induce a bullet to readily yaw in tissue, you need either a centre of bullet mass well behind the centre of bullet drag, as in the Mk 7 .303 British with its aluminium tip, or else an asymmetric bullet point like the loffelspitz “spoon tip” bullet. While it’s possible that the designers of the 5.56 NATO may have deliberately made a bullet that tends to yaw early in the target, it could be simple coincidence. The necessarily thin case and high velocity of the 5.56 is very likely to result in a deformed bullet tip on impact for example, which would tend to cause a yaw. All spitzer bullets are going to have some tendency to yaw in any case.
One point of interest is that the US version of the 7.62 NATO was far less prone to fragmenting in the target than the West German version of the same round, see http://ammo.ar15.com/project/Fackler_Articles/wounding_patterns_military_rifles.pdf (last page). It seems odd that the American military bullet designers would miss an opportunity to make their other calibre more deadly, if they specifcally designed the 5.56 to yaw.
Clearly to settle the issue and impose widespread standards, we need something akin to the
VHS vs. Beta format war.
Only this war will have actual casualties…
Apologies if this was already mentioned, but I thought that there are 2 reasons for the excessive damage done by small bullets
once they enter the body, their path becomes unstable and they tend to “bounce around” rather than taking a straight path through.
the tumbling effect is related to the instability in the sense that once the tip of the bullet no longer faces the direction of travel, there are tremendous stresses on its structure which cause it to fragment. It is the fragments which do the damage.
As to #2, this was a way of getting around the international treaties regarding hollow points. A small round gave you a fragmenting round that was not specifically designed to fragment and therefore was not a violation of any treaty.
I could be completely wrong on both points but I know I have heard many times that .22 is prefered by assassins since the bullets do so much more damage once in the body. Also the 5.62 rounds are only slightly bigger in cross section than a .22 so I assume it behaves in a similar manner.
In my experience, there is no faster way to generate a giant hit-gaining internet debate than pose the question about whether the M-16/M-4 5.56mm family should be replaced by weapons employing larger caliber ammunition. Drags all the “experts” out of the woodwork, for both sides.
That said, real experts have been working this issue for as long as I’ve been aware of it. The official verdicts always appear to be variations on, “It depends,” but it is always interesting to note that when given a choice in the matter, soldiers such as those in U.S. SOCOM choose to replace their 5.56mm weapons with larger caliber rifles.
I wasn’t aware that smallness in and of itself was a factor. As mentioned upthread the move to 5.56 was both to increase the number of rounds carried and an attempt to make full-auto fire controllable. The main feature of 5.56 rounds is that they’re “spitzer” shaped- comparatively long and narrow, making them more likely to tumble.
I’ve heard of, but never understood, the preference for the .22 as an assassination weapon, unless it’s a question of being able to suppress to very low noise levels.
The M-16 was designed around the 5.56 round.
It’s an oldschool spy thing, with lightened loads you can just push the 22 to someone’s body (or head) and pop 2 rounds in the middle of a crowded street without people really noticing it. Traffic noise tends to hide the sound even without a suppressor. I doubt any pro would use one tho.
Screenwriters seem to love the idea tho, so probably some mob guy somewhere who’s seen too many movies (I.e. any mob guy) might think it’s the thing to do. When IRL cops see a guy shot with a 22, they’re bound to think one of three things, either it’s some idiot (the mob), or it’s gang related (cheapest POS revolvers around, pop and drop)…or the shooter is a woman (small enough to be a purse gun).
If I had to shoot someone quietly, at close range, I’d use one of these.
According to Vengeance, a book about the 1972 Munich Olympics tragedy, and some other sources, Mossad’s covert agents carried Glock 22s during the 80s. I’m wondering if somebody misinterpreted that to mean they carried pistols chambered in .22.
ETA: now that I double check, the Glock 22 only came out in 1990, so that can’t be right either.
The .22 LR has a high sectional density, and thus penetrates well even at subsonic velocities, while generally not overpentrating and thus posing a hazard to bystanders. It is chambered in small, flat, pistols with simple straight blowback action. While any subsonic pistol round can be suppressed to the point that the action of the gun is louder than the muzzle blast, the .22 LR has a much smaller gas volume and the suppressor can be correspondingly smaller.
The Mossad (counterintelligence and covert action agency of Israel) allegedly favored the Beretta 950 with and without a threaded on silencer. This weapon was reportedly used by other intelligence agencies as well in the 'Fifties, hence why Ian Fleming selected the .25 ACP version for his hero to carry in the Bond stories (eventually replaced by a .32 ACP Walther PPK as suggested by one of his readers, a Maj. Boothroyd, in a critical letter). The intended use of the pistol was at near contact range or closer, often in a crowd.
The US Army Special Forces, CIA Special Activities Division, and other covert operators used larger frame .22 LRs (modified High Standard Supermatic/Olympic and Ruger Mark II pistols) with integral silencers. These were intended to be used at longer ranges (up to 15 meters) to affect silent removal of sentries.
Both the Soviets and Chinese developed a number of silenced pistols that were around .22" diameter using a variety of methods to silence the round, some of them quite novel.
Stranger
Except that those articles make a different point than I was, and even then, you are confusing the round with the weapon. The m4 is a very short maneuverable gun, great for urban combat, less so for long range. The round itself is quite capable of extreme long range accuracy and killing power, but not as much when shot through a barrel shorter than many .22lr rifles.
The other point brought up is that since the Hague convention disallows expanding ammo, unarmored targets are more likely to receive through and through wounds from fmj rounds. A bigger fmj round isn’t going to cure that issue.
Every round has tradeoffs. This is so obvious that I didn’t think it needed saying. But the persistant rumors about lack of lethality are a myth.
I haven’t actually noted that, and I am not sure it’s true at all, unless you’re talking about snipers/designated marksmen, which would be somewhat irrelevant.
Nitpick: effect.
[quote=“engineer_comp_geek, post:20, topic:551851”]
I second this. When dear old dad bought me my first handgun (a Glock 22 - .40 cal), he also bought me a kit so that I could swap out the barrel and magazine and fire .22 rounds with it. Hell of a lot cheaper, the .22 is great for learning (and relearning) proper form, and is great for teaching chicks to shoot because of the low recoil. And the ammo is damn near “free.” Did I mention the chicks?