Why were there so few wounded in the CT school shooting?

[Gray_Ghost]

@Magiver

a 223 cartridge is like a 50 caliber explosive cartridge driving a 22 sized thin-jacketed bullet. It’s a relatively slow spinning bullet so it both tumbles and breaks up on impact due to the high velocity…

I’m confident in posting that this–at least the 50 caliber explosive hyperbole—is incorrect. It’s late, I’m tired, and this will be brief. Plus, I’m hoping someone like smithsb shows up to the thread and corrects my mistakes.

We have no information on the twist rate of shithead’s (SH)—I refuse to use that vile fucker’s name—rifle, hence we have no info on the spin rate of his bullets. Assuming that most of the wounds were caused by a .223 or 5.56 mm rifle (and I don’t know which it was, and they’re not exactly interchangeable. I’ve also read that the rifle was in the car.), and assuming a MV of around 3200 FPS, the bullets could have been spinning anywhere from 460,000 RPM (1 twist in 5 inches) to 192,000 RPM (1 twist in 12 inches) This is comparable to many “high-powered rifle” spin rates. My .270 Winchester has a 1 in 9 twist, and a MV of ~2900 FPS. Its bullet RPM would be 232,000, on the lower side of the above range. You can read about what one author does with this RPM data (and where I got the formula for calculating it, here.)

What does happen and is described here, among other places, is that the standard 55 grain FMJ bullet used in the 1960s and 1970s, used to break at the cannelure, after one or so end over end rotations in tissue. The same behavior was noted in West German 7.62mm 150(?) grain ammunition, BTW. All bullets with their center of gravity behind their geometric center (or center of lift, I forget)—like nearly all rifle bullets with a lead core—will exhibit this end over end tumbling behavior in dense media. They may or may not break up though. Breaking up lowers the penetration of the round (not usually an issue with rifle bullets) and enhances the volume of tissue disrupted by the bullet. The spin rate just alters how long in the dense media it takes before they start tumbling.

Anyway, this tumbling in the 55 grain bullet (and the later 62 grain SS 109) would usually fragment the forward part of the bullet—with devastating temporary cavity results, while the rear of the bullet continued penetrating. (Scroll down in my previous link to where the author describes Dr. Fackler’s findings.) The wiki for the 5.56mm X 45 cartridge goes into much more detail about selecting the proper spin rate for the weight of bullet. This is an artifact of certain combinations of NATO bullets and spin rates and velocities. It is renowned for not happening after a certain range from the muzzle. As velocity depends on barrel length, all else being equal, this results in short-barrel M-4s not exhibiting the lethality beyond 200 meters (and I’ve read of 100 meters or less being an issue with some of the ridiculously short (6.5-10.5 inch) barrels) that one would wish. This isn’t really a consideration for SH though, as I’m guessing that most wounds were contact or within 5 meters or so.

Anyhow, Cliff’s notes: close range rifle bullets are usually devastating; closely selected examples of 5.56mm ammunition more so. Most people shot with handguns survive their wounds. This isn’t the case with rifle wounds. In any event, it’s not like a 50 caliber explosive round, which is what prompted me to write the reply. Aside, muzzle kinetic energy for your generic 5.56 mm round: 1300 ft-lbs. For the .270 Winchester I use to harass deer every autumn, ~2400 ft-lbs. For a .50 BMG, ~18,000 ft-lbs. It’s quite a difference.

[toofs]

@Magiver

a 223 cartridge is like a 50 caliber explosive cartridge driving a 22 sized thin-jacketed bullet. It’s a relatively slow spinning bullet so it both tumbles and breaks up on impact due to the high velocity.

They said on the news today they don’t know how many times his mother was shot. I’ve also heard it was a head shot(s). I take that to mean the bullets really messed her up.

Actually, the rifling twist rate is 1:7 for the 5.56x45mm NATO chambering, which is pretty fast. The civilian versions (.223 Remington) are sometimes 1:9.

Also, the 5.56x45mm is nowhere near the destructive power of a .50BMG. Comparing apples to Buicks here.

[Magiver]

@Gray_Ghost

I’m confident in posting that this–at least the 50 caliber explosive hyperbole—is incorrect. It’s late, I’m tired, and this will be brief. Plus, I’m hoping someone like smithsb shows up to the thread and corrects my mistakes.

It wasn’t meant to be a literal comparison. It was a mental visual to explain the power behind the smaller bullet. don’t get your panties all wadded up.

@Gray_Ghost

We have no information on the twist rate of shithead’s (SH)—I refuse to use that vile fucker’s name—rifle, hence we have no info on the spin rate of his bullets.

a .223 has a spin rate of about 1:12 which is faster than it’s original setup but still relatively slow. It has the minimum spin rate needed to track properly in all weather conditions.

@Gray_Ghost

All bullets with their center of gravity behind their geometric center (or center of lift, I forget)—like nearly all rifle bullets with a lead core—will exhibit this end over end tumbling behavior in dense media.

yes and it matters whether it’s a heavy or thin jacketed bullet. The .223 is a thin jacketed bullet and more likely to disintegrate upon impact versus something like the bullets used in the JFK assassination which ricochet’d all over the place but remained intact.

so without a long winded dissertation of the number of grains used in his particular cartridge the point stands that an AR-15 (M-16) creates a destructive hole in what it hits which is why it was chosen by the armed forces in the 60’s and is still used today.

[drastic_quench]

Also, it’s been reported that his mom saw to it that he got lots of range time to practice. That accounts for a significant difference. Some untrained loon with the same guns very likely wouldn’t have been as devastating.

[Magiver]

@toofs

Actually, the rifling twist rate is 1:7 for the 5.56x45mm NATO chambering, which is pretty fast. The civilian versions (.223 Remington) are sometimes 1:9.

I’m no expert but I don’t think you’re suppose to fire 5.56 military rounds in an AR-15. and the twist rate of a .223 was originally 1:12. You can buy some with a faster rate but that defeats the destructive force of the bullet.

@toofs

Also, the 5.56x45mm is nowhere near the destructive power of a .50BMG. Comparing apples to Buicks here.

Who said anything about a BMG? I don’t think the person I responded to had a clue what that his. I said 50 caliber as in the classic hand gun.

The rifle was chosen for it’s killing power. If you want to calculate the size of the hole it makes in little kids then have at. I’ve made my point.

[the_diego]

You know, I’ve a feeling professional shooters and gun writers won’t spend as much time talking about twist rates as you guys do. You see, twist doesn’t affect velocity or bullet integrity. It improves accuracy. As to the claim that a wrong twist will induce “key-holeing” when a target is hit, the last time I read about that was in the Vietnam war. It suffices to say that a 5.56mm bullet at close range will have enough killing power, especially for children.

[Gray_Ghost]

This isn’t the thread for a discussion of terminal ballistics, in general or as it applies to the 5.56 X 45mm or .223 Remington cartridge. Suffice it to say that those interested in the subject will be easily able to find reams of data and articles on it.

In any event, the killer’s rifle selection—so long as he used one in preference to a handgun—would have had little difference on the outcome of the massacre. For most people, semi-automatics fed from a detachable magazine, like the rifle used at Sandy Hook, allow for a higher rate of fire than other types of rifles. Higher rate of fire means more shots from the killer before the police or other armed persons show up. However, from the news reports I’ve read so far, he appears to have taken enough time to have ensured the death of most of his victims by shooting them multiple times. I have not seen where the police response interrupted him as he was killing his victims; therefore, I’m not sure whether his choice of an ugly black rifle vs. say a rifle you’d use for deer hunting, made much of a difference in the outcome. (See, by contrast, the fates of the 10 schoolgirls shot with a handgun in the Amish Schoolhouse Massacre. 5 died, while 5 lived, even though they were bound and the killer attempted to shoot them all in the head. The killer in the Amish Schoolhouse also did not have enough time—the police were in the process of breaking down the door to the schoolhouse—to ensure that all of his victims were killed with multiple shots.)

So, to answer the OP, the reason there were so many dead than wounded in this particular massacre is due to: the killer using a center-fire rifle, having the time to shoot the victims multiple times, the victims being small children, being at close range to the victims, and being largely uninterrupted during the massacre, (the two preceding points allowing the killer a much better chance of shooting the victims in the chest or head). Change at least the first two, and the number of wounded to killed would increase, IMHO.

Gun control advocates are trying to change the likelihood of the first point and a bit of the second, by restricting the availability of faster-firing rifles and high capacity magazines. Conversely, ‘CCW for teachers/school workers’ advocates are trying to change the second and last points on the idea that a spree shooter will either be stopped by the CCW holder or the spree shooter will be too busy trying to fight the CCW holder to be able to herd his victims to where he can easily kill them.

[al27052]

@drastic_quench

Also, it’s been reported that his mom saw to it that he got lots of range time to practice. That accounts for a significant difference. Some untrained loon with the same guns very likely wouldn’t have been as devastating.

Hindsight’s 20/20, but wow…

[Leo_Bloom]

I’m following but not really absorbing, given the time I’ve put into it, this discussion.

In another thread the distinction between “assault weapons” (idiotic word) is gone over.

Let me ask here: news reports breathlessly report that the killer used a “high power” weapon. And, of course, “high power” weapons are often singled out, without apparent consistency, by press and anti-gun people.

What are the real criteria? Obviously the definition depends on what the use the weapon is suited, but how to knowledgably discuss this?

[md2000]

One news report also mentioned that one girl was the only survivor in the first classroom, who came out covered in blood but said she survived by playing dead. “I’m alright mommy, but all my friends are dead.”

Does this suggest the multiple shots were not deliberate retargeting but the result of holding down the trigger on the AR-16 (they claim this was used on the news) while aiming once firing off several shots in succession at someone?

[Gray_Ghost]

@Leo_Bloom

…Let me ask here: news reports breathlessly report that the killer used a “high power” weapon. And, of course, “high power” weapons are often singled out, without apparent consistency, by press and anti-gun people.

What are the real criteria?..

The NRA has “High Power Rifle” (Pdf) as a separate class of competition. Colloquially, it is any center-fire rifle cartridge, and distinguishable from “Smallbore” rifle, which is fired with .22 LR the vast majority of the time. Back in the day, High Power matches were shot with 30.06 Springfield and 7.62 X 51mm NATO / .308 Winchester. Later on, and dominating most of the results last I checked, was 5.56 X 45mm. The rules for High Power don’t limit competition to those cartridges, but do restrict things to “no larger than .35 caliber [sic].” So you can show up with .338 Lapua, I guess, though without a muzzle brake, and greatly annoy every shooter around you as long as your shoulder holds out.

As far as energy goes, I’ve a post earlier in the thread listing the differences in muzzle energy between average loadings of the 5.56, .270 Winchester, and .50 BMG. The .22 LR used in small bore competition has an average muzzle energy around 120-140 ft-lbs. Or, about 1/10th that of the 5.56 I cited earlier.

So, I don’t have an issue with the Bushmaster rifle that was used being called, “high-powered.” It’s eligible to compete in the near-identically named NRA competition, after all.

[JKellyMap]

@al27052

Hindsight’s 20/20, but wow…

Wow is right. Nancy Lanza may be lucky she died that day. If she hadn’t, it’s possible someone would have killed her out of (justified*) anger during the past few days…and her killer might not have been so kind as her son was in sparing her any prolonged physical pain.

(*I don’t mean that her murder by a vigilante would have been justified as a proportional response, but that anger at her failure to see how “gun availability, trainig, and enthusiasm + grown child in house with serious social adjustment issues = rather high probability of serious consequences” was – and is – very much justified.)

ETA: Sorry for the hijack. Carry on.

[muldoonthief]

@md2000

One news report also mentioned that one girl was the only survivor in the first classroom, who came out covered in blood but said she survived by playing dead. “I’m alright mommy, but all my friends are dead.”

Does this suggest the multiple shots were not deliberate retargeting but the result of holding down the trigger on the AR-16 (they claim this was used on the news) while aiming once firing off several shots in succession at someone?

The AR-15 is not fully automatic. It’s semi-automatic. You have to release and pull the trigger for each round fired.

[md2000]

@muldoonthief

The AR-15 is not fully automatic. It’s semi-automatic. You have to release and pull the trigger for each round fired.

But it would be quick and simple (I assume) for a nutbar with a rage issue to fire multiple shots in quick succesion at the same target? The fact that one girl survived untouched suggests he did not methodically re-check each victim; plus, IIRC, 2 died in hospital afterwards.

But I too am surprised that there were so few just injured. I assume unfortunately the close range was a factor.

[drastic_quench]

@md2000

But it would be quick and simple (I assume) for a nutbar with a rage issue to fire multiple shots in quick succesion at the same target? The fact that one girl survived untouched suggests he did not methodically re-check each victim; plus, IIRC, 2 died in hospital afterwards.

But I too am surprised that there were so few just injured. I assume unfortunately the close range was a factor.

Yes. There’s not a wallop of a kick that throws you off target with an AR.

[Kevbo]

@Gray_Ghost

So, I don’t have an issue with the Bushmaster rifle that was used being called, “high-powered.” It’s eligible to compete in the near-identically named NRA competition, after all.

Your analysis is correct, but the press likes to give the impression that “Assault Weapons” are especially powerful, when in fact they are not sufficiently powerful to be legal for hunting deer in many states, as the energy level is thought insufficient for a humane kill. Some of that is East vs. West: The West has larger mule deer, and shots are often taken at longer range due to the lack of dense hardwood forests.

So while “high-powered” might be technically correct, the press is failing to note that these guns are in fact less powerful than most deer rifles, and giving the impression that because the military uses this caliber, it is especially powerful. I won’t speculate on how much of this is ignorance, and how much intentional deception…it is wrong regardless the reason.

In military terms, these are medium-power rifles…powerful enough for most fighting, but with lighter weight ammunition and less recoil than a battle rifle. It is what your average soldier would be issued. Designated marksmen and snipers would usually be issued rifles with significantly more powerful chamberings.

I also occasionally hear the press use the term “high-caliber”. This term is meaningless. As near as I can determine it was invented by the writers of CSI or similar television shows.

[Leo_Bloom]

This is a cross-post from the current thread Non-LEO/Military Use of Automatic Weapons:
The Pentagon defines the term “assault rifle,” and David Kopel quotes that definition in an article in the Journal of Contemporary Law. He writes:

As the United States Defense Department’s Defense Intelligence Agency bookSmall Arms Identification and Operation Guideexplains, “assault rifles” are “short, compact, selective-fire weapons that fire a cartridge intermediate in power between submachine gun and rifle cartridges.”[21]In other words, assault rifles are battlefield rifles which can fire automatically.[22]
”

(b) DEFINITION OF SEMIAUTOMATIC ASSAULT WEAPON- Section 921(a) of title 18, United States Code, is amended by adding at the end the following new paragraph:

(30) The term semiautomatic assault weapon’ means–

`(A) any of the firearms, or copies or duplicates of the firearms in any caliber, known as–

`(i) Norinco, Mitchell, and Poly Technologies Avtomat Kalashnikovs (all models);

`(ii) Action Arms Israeli Military Industries UZI and Galil;

`(iii) Beretta Ar70 (SC-70);

`(iv) Colt AR-15;

`(v) Fabrique National FN/FAL, FN/LAR, and FNC;

`(vi) SWD M-10, M-11, M-11/9, and M-12;

`(vii) Steyr AUG;

`(viii) INTRATEC TEC-9, TEC-DC9 and TEC-22; and

`(ix) revolving cylinder shotguns, such as (or similar to) the Street Sweeper and Striker 12;

`(B) a semiautomatic rifle that has an ability to accept a detachable magazine and has at least 2 of–

`(i) a folding or telescoping stock;

`(ii) a pistol grip that protrudes conspicuously beneath the action of the weapon;

`(iii) a bayonet mount;

`(iv) a flash suppressor or threaded barrel designed to accommodate a flash suppressor; and

`(v) a grenade launcher;

`(C) a semiautomatic pistol that has an ability to accept a detachable magazine and has at least 2 of–

`(i) an ammunition magazine that attaches to the pistol outside of the pistol grip;

`(ii) a threaded barrel capable of accepting a barrel extender, flash suppressor, forward handgrip, or silencer;

`(iii) a shroud that is attached to, or partially or completely encircles, the barrel and that permits the shooter to hold the firearm with the nontrigger hand without being burned;

`(iv) a manufactured weight of 50 ounces or more when the pistol is unloaded; and

`(v) a semiautomatic version of an automatic firearm; and

`(D) a semiautomatic shotgun that has at least 2 of–

`(i) a folding or telescoping stock;

`(ii) a pistol grip that protrudes conspicuously beneath the action of the weapon;

`(iii) a fixed magazine capacity in excess of 5 rounds; and

`(iv) an ability to accept a detachable magazine.’.