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benEzra

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Gender: Male
Hometown: Eastern North Carolina
Home country: United States
Current location: Eastern NC
Member since: Wed Dec 1, 2004, 03:09 PM
Number of posts: 11,712

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Well, to get pedantic...

You have strayed a bit from explaining why the least powerful and rarely misused civilian rifles are ZOMG THE MOST DEADLIEST EVAR, but if you want to get pedantic....

You said:

"For something to cavitate is to cause cavitation - to itself. Cavitate is an *intransitive*verb as you are using it, where the verb does not apply to a direct object."

Either usage is correct, and both are common in the peer reviewed fluid dynamics literature. A cavitating/supercavitating projectile creates a creates a temporary cavity in the fluid medium, not in itself. Yes, cavitating/supercavitating can refer to the fluid flow (especially when considering a system in the rest frame of the solid object, with the surrounding fluid portrayed as moving), but it is also correct to refer to the projectile as cavitating/supercavitating. In both cases, the temporary cavity is created in the fluid medium. For example:

Owis FM, Nayfeh AH, "Numerical simulation of 3-D incompressible, multi-phase flows over cavitating projectiles", European Journal of Mechanics - B/Fluids 23:2, Mar-Apr 2004 pp. 339-351 (http://www.sciencedirect.com/science/article/pii/S0997754603001171).


Kulkarni SS, Pratap R, "Studies on the dynamics of a supercavitating projectile", Applied Mathematical Modeling 24:2 (1 Feb 2000), pp. 113-129. (http://www.sciencedirect.com/science/article/pii/S0307904X99000281)


Rand R, Pratap R, Ramani D, Cipolla J, Kirschner I, "Impact Dynamics of a Supercavitating Underwater Projectile". Sacramento, CA: Proceedings of the 1997 ASME Design Engineering Technical Conferences, 1997. (http://www.math.cornell.edu/~rand/randpdf/ahsum.pdf)


Ditto cavitating/supercavitating hydrofoils:

http://www.globalsecurity.org/military/systems/ship/hydrofoil-limits.htm
"In order to prevent damage by cavitation, foils referred to as supercavitating foils have been developed. With a supercavitating foil, a large vapor-filled cavity, referred to as a separation bubble, is formed over substantially the entire upper surface of the foil. Vapor bubbles in the cavity are carried beyond the trailing edge of the foil and collapse in the water aft of the foil, so that shock waves produced by the collapse of the bubbles have much less effect on the foil than in a normal cavitating foil."


Baker ES, Notes On the Design of Two Supercavitating Hydrofoils. Bethesda, MD: Naval Ship Development Center, 1975 (http://www.dtic.mil/dtic/tr/fulltext/u2/a030749.pdf).


The usage isn't new, and goes back to at least the 1960s, to the very beginning of computational fluid dynamics. That doesn't mean your use of the term is wrong, either, it's just a different usage, and you see both ways in the fluid dynamics literature.

More broadly, I think your resistance to seeing the temporary cavity as a physics/fluid dynamics phenomenon (and therefore understandable and predictable) stems from the misconception of reading articles and definitions about low-order cavitation (e.g. microscopic cavitation bubbles, small-area sheet cavitation, prop-tip vortex cavitation, pump impeller cavitation, etc. that occur at relatively low Reynolds numbers/high cavitation numbers and are a major engineering headache), and thinking that's all there is to the study of cavitation. Fully developed large-scale cavitation structures, like the attached cavity formed by a bullet in a fluid medium, are described by the same equations and principles; the difference is simply the velocity of the relative flow between the projectile/object and the fluid medium.

The thing is, transition from slow-speed bubble cavitation to fully developed attached-cavity cavitation (where the temporary cavity is much larger than the projectile creating it, as with firearm projectiles) occurs at no more than a few dozen meters per second for a bullet-sized object; any velocity greater than that will produce a fully developed, vapor filled temporary cavity. Since all bullets are traveling between 250 and 1500 meters/sec, they are all waaaaay above the velocity threshold to undergo boundary layer separation and fully developed cavitating flow (e.g. supercavitation) and produce an attached temporary cavity far larger than the projectile itself. In mathematical terms, the cavitation number << the critical value (calculated thusly).

"Bullets do not cavitate, (unless they are mechanically affected which they cannot in less than a second), they cause cavitation due their mass, velocity, rotation or perhaps tumble."

They *do* cavitate---or if you prefer, cause cavitation; either use is acceptable---and it is because of their velocity and the energy they impart to the fluid medium; in a nutshell, they push the medium out of the way so fast that the medium's momentum moves it further than the diameter of the bullet, and it takes a few milliseconds for the displaced fluid to reverse direction and collapse the cavity. The shape and toughness of the bullet determine the shape of the temporary cavity, but the energy of the bullet determines the size.

But here are the more important points that you have gotten away from, with regard to civilian ownership of centerfire .22's:

(1) All bullets produce a temporary cavity, regardless of what you call it.

(2) .223 Remington produces a larger temporary cavity than most handgun bullets.

(3) .223 Remington produces a smaller temporary cavity than most rifle bullets.

(4) Temporary cavity size is not particularly associated with lethality, but at rifle velocities seems to be associated with temporary incapacitation due to transient vascular pressure effects and the body's (presumed) vasodepressor/vasovagal response. Some researchers have argued for temporary incapacitation effects with some handgun rounds also, but the evidence is inconclusive.

(5) Permanent cavity size is highly associated with lethality.

"There is a diff between cavitation of metallic parts & cavitation used in wound ballistics. The cavitation noted below is NOT what we are concerned with. We are not in an engineering context discussing temporary wound cavities, we are in a medical context."

If you fall off a ladder and break a bone, the consequences of the fracture are medical, but Newtonian physics and materials science/engineering tell you how and why the bone broke, can predict the compression/torsion/shear that a particular bone can withstand before breaking, and can tell you what kinds of accidents can generate those forces.

Likewise, if a high speed projectile enters a fluid medium---whether water, ballistic gelatin, or flesh---the consequences of a wound can be medical, and are mostly associated with the permanent cavity. But the impact itself, and the formation of the temporary cavity, are described by high Reynolds number fluid dynamics, not medicine. Temporary cavity is a mathematically describable physical phenomenon, and is determined primarily by the kinetic energy, shape, and deformation of the upset projectile.

"Cavitation is a significant cause of wear in some engineering contexts. Collapsing voids that implode near to a metal surface cause cyclic stress through repeated implosion. This results in surface fatigue of the metal causing a type of wear also called "cavitation". The most common examples of this kind of wear are to pump impellers, and bends where a sudden change in the direction of liquid occurs. https://en.wikipedia.org/wiki/Cavitation"

Again, you are confusing low-order bubble cavitation (lower Reynolds number, higher cavitation number) with high-order, fully developed attached-cavity boundary layer separation (very high Reynolds number, very low cavitation number). It's still cavitation, but at the high-energy end of the spectrum (aka supercavitation), and you don't seem to be able to grok that they are two ends of the same continuum.

"ezra: due to low-order cavitation and subsequent bubble collapse on the surface of the cavitating object, causing metal fatigue.
jimmy: That is irrelevant to very-high-speed objects like bullets."

Yes, that's what I'm saying. High speed cavitation involves the formation of attached vapor-filled cavities, e.g. the temporary cavity, not tiny bubbles.

"No, the bullet itself does not form any cavity. The cavity formed is the tissue cavitating, not the bullet. As I've said previous, 'cavitate' has morphed into being accepted as you are using it, bullet wise, tho I believe it is invalid usage."

The bullet does indeed create the temporary cavity. Here's a larger-caliber Hornady deer hunting bullet doing just that, in ballistic gelatin:



.223 bullets just happen to create a smaller temporary cavity (and more importantly for hunting, a smaller permanent cavity) than more powerful rifle rounds do, all else being equal.

Given that we are talking about the least misused guns...

...I think that all this handwaving about centerfire .22's is rather silly. Still, since you bring it up, you might want to brush up on your fluid dynamics a bit.

(Warning: Contains minutiae!)

"I don't agree that 'rifle bullets cavitate, period'. I'm not sure bullets technically cavitate at all. I think the term 'bullets cavitate' has simply morphed into being, similar to how 'incredible' & 'unbelievable' have morphed into different meanings from what they originally meant.

Does a bullet cavitate, or does tissue cavitate? or both?"

Cavitate is a verb; cavitation is a noun. To cavitate is to cause cavitation, e.g. the formation of a gas filled cavity ("bubble" or "void") in a fluid medium, in which the local pressure is less than the vapor pressure of the surrounding liquid (which is why cavitation only produces a *temporary* cavity, as opposed to a bubble of gas at ambient pressure). In our context, we are talking about cavitation caused by flow separation around a fast-moving solid object in a fluid medium, and since the cavity is collapsing well behind the object, it is technically supercavitation if you get right down to it.

http://www.merriam-webster.com/dictionary/cavitate

"Onelook Dictionary website has 11 dictionary entries for 'cavitate' (mostly irrelevant to this discussion), while it has 25 dictionary entries for 'cavitation', some also irrelevant, but the question is why don't most major dictionaries have a def for 'cavitate' and only for 'cavitation'?
Collins dict: cavitate: to form cavities or bubbles
Merriam Webster: to form cavities or bubbles
wordnik: To form vapour bubbles in a flowing liquid in a region..
Century Dictionary and Cyclopedia To form holes or cavities within an agitated liquid; react upon the water with *cavitation: said of a screw propeller. http://www.onelook.com/?w=cavitate&ls=a"

Yes. A fast-moving solid object creating a cavity within a fluid medium is cavitation. Also said of high speed projectiles in water or other dense fluid mediums.The temporary cavity of a rifle bullet is basically textbook supercavitation (the cavity collapses well behind the projectile). Here's a basic primer: https://en.wikipedia.org/wiki/Supercavitation

Thing is, while the displacement caused by cavitation probably does cause some tissue injury, it doesn't appear to be a major contributor to lethality. Temporary cavity may result in temporary incapacitation (perhaps due to vascular reflex), but most wound ballistics experts (such as Fackler et al) point to the size and location of the permanent cavity as the primary predictor of lethality.

"The above defs mean 'to form' within a structure, or body in our case, I doubt the device used to form the cavity."

A rifle bullet impacts a deer, and a temporary cavity suddenly forms with its apex on the bullet, trailing behind the bullet for a foot or more. Hint: the bullet is the cause of the cavity.

"If a bullet were to cavitate it would become pitted due to collapsing partial vacuums or impingements, irrelevant to this discussion."

Ummm, no. The cavity a bullet causes is larger than the bullet, and the collapse occurs a foot or more behind the bullet.

Here's a video of a 7.62x39mm round creating a temporary cavity in water, at 27,500 frames per second. Watch the whole thing, and note particularly the temporary cavity formed by flow separation around the cavitating bullet, as opposed to the turbulent bubble formed by the powder. See 2:44 (with temp cavity collapse at 2:51) and 4:44 and following.



FWIW, pitting due to cavitation occurs only in low-grade (non-"super") cavitation, where the cavity is smaller than the solid object creating the cavity, such that the cavity collapse occurs on the object's surface. Over time, constant exposure to low-grade cavitation causes metal fatigue at the surface of the metal, eventually leading to erosion and pitting. That process occurs over hours, weeks, months, or years of cumulative exposure, not in a fraction of a second...and it wouldn't apply to a rifle bullet anyway, because the cavity collapse occurs way behind the bullet, not on the back of the ogive.

"In an alternative definition of 'cavitate', a screw propeller will cavitate at, generally, higher ship speeds full or flank, but it does so over minutes, hours, days, months in the water. A bullet can pass thru a soft target in a fraction of a second, does it truly 'cavitate' when it truly cannot?"

Yes, it does. A propeller cavitates when the blade speed through the water is high enough to cause flow separation at that angle of attack. At relatively low blade speeds, it is dependent on blade angle relative to the oncoming flow (e.g. flow separation due to hydrodynamic stall) but at a sufficiently high blade speed it is inevitable. Still, because the blade speed of a boat or ship is relatively low in absolute terms, the cavity collapse often occurs on the surface of the blade itself, leading to metal fatigue and eventual erosion/pitting at the region of constant collapse.

One way around that, of course, is to use a supercavitating prop, designed to spin fast and shaped such that the temporary cavity collapses behind the blade...just like the temporary cavity caused by a bullet in a fluid medium. And bullets are waaaay faster than props, so the collapse occurs further back (go up and look at that video again).

Here is a good representation of a flow field around a bullet in a fluid medium:


An object (black) encounters a liquid (blue) at high speed. The fluid pressure behind the object is lowered below the vapour pressure of the liquid, forming a bubble of vapour (a cavity) that encompasses the object.
https://en.wikipedia.org/wiki/Supercavitation

It's also possible to design a bullet of high sectional density and a pointed tip that induces early flow separation, in such a way that it doesn't lose much energy to either hydrodynamic drag or skin friction; the temporary cavity is only large enough for the bullet to fly in. Bullets of that sort don't just brake to a stop in a foot or two of supercavitation, like regular bullets do, but can travel for dozens or hundreds of feet underwater due to their much lower rate of energy loss. That would make for a pretty lousy hunting bullet, though, as the permanent cavity would be very narrow.

"any cavitation bullet creates does not affect it whatsoever, since it is long gone by the time the temporary wound cavity collapses. "

Yes, exactly. Bullets (even handgun bullets) travel far too fast for the flow separation cavity to collapse back onto the projectile itself, except for perhaps during the last few mm of travel.

"If bullet hits bone or does not exit, collapsing tissue on the back end has no relevant affect on a bullet, it's a one trick pony & does not get shot again."

Yes. Your point?

"This is actually not what is meant when referring to a bullet however, since bullet wise we are speaking of 'medical related' cavitation, not mechanically affected cavitation."

A bullet does not cause flow separation and temporary cavity mechanically? How else do you think it does it?

Temporary cavity is an example of very high speed cavitation (supercavitation) in a fluid medium due to flow separation and the inertial effect of radial fluid displacement. It is a hydrodynamic effect, not a "medical" one, although there may be medical consequences (such as a temporary spike in fluid pressure in the vicinity). The medical consequences of the permanent cavity are what determine lethality, though.

"'your-boat-guy' website, how a propeller cavitates in the bubbly sense: Many propellers partially cavitate during normal operation, but excessive cavitation can result in metal erosion or "cavitation burn" to the prop's blade surface."

Yep, due to low-order cavitation and subsequent bubble collapse on the surface of the cavitating object, causing metal fatigue. That is irrelevant to very-high-speed objects like bullets.

"cav·i·tate To form cavities in an organ or tissue .. cavitate formation of cavities.
cav·i·ta·tion 2. the formation of cavities, esp in a part of the body. 3. Medicine The formation of cavities in a body tissue or an organ, especially those formed in the lung as a result of tuberculosis. http://www.thefreedictionary.com/cavitate"

Flow separation and temporary cavity formation around a high-speed object in a fluid medium is in the realm of fluid dynamics, not medicine. Again, brush up on your fluid dynamics.

For a discussion of cavitation (in the fluid dynamics sense) in the context of wounding from hunting rifle bullets, see this article, under the subheading "II. D. Mechanics of Cavitation".

"new to me, super cavitation: A propeller is said to be fully cavitating when the whole of the back is covered in sheet cavitation. This phenomenon is also called super cavitation.. "

Yep. Supercavitating props are used on a lot of race boats, and some companies even played with supercavitating hydrofoils for a while. But supercavitation occurs whenever an object moves sufficiently fast in a dense fluid.

"Most larger caliber rifle-hunting bullets (i.e, larger than .223 --bE) are more likely to cause a quicker death to the animal, too."

Yup. That's because they cause more severe wounds than .223, which is the least powerful rifle cartridge in common use. Larger caliber rifles are also more lethal to humans, though you'd never know it from your rhetoric.

This does go to show just how dishonest the gun control lobby was when it claimed you can't hunt with an AR because it will "blow the deer to smithereens", though. Again, you're trying to make the least powerful rifle cartridges sound ZOMG SUPER SCARY!! compared to more powerful rounds, but the fact is that .223 is less lethal than most rifle rounds. And you have admitted yourself that rifles are the least misused of all firearms....so why the obsession with banning the most popular ones?

Thoughts...

Here's what you said:

"If cavitation occurs the animal can wander off & be in unbearable pain for days, moreso than with other hunting bullets."

There is no "if cavitation occurs"; rifle bullets cavitate, period, and most larger calibers cause more cavitation than .223 does, since the volume of the temporary cavity is roughly proportional to the energy transferred.

A fragile, light-for-caliber bullet at 3000 to 4250 ft/sec (40 or 55gr .223 JHP, 55gr .22-250, 58gr .243, 90gr .270, 55gr .30-06) will produce a much shorter, but wider, wound track than a limited-expansion, bonded-core bullet (like .223 50gr Barnes TSX, 60gr Nosler Partition, 62gr Remington Core-Lokt) or heavy-for-caliber bullets (77gr bonded core .223, 110gr .243, 140gr .270., 180gr .30-06). But the temporary cavity size is still proportional to the energy.

For killing a large game animal humanely, the wound has to be deep enough to reach the vital organs after penetrating the shoulder. A .223 can create a deep cavity with a bonded core hunting bullet, but it's not very wide, and hence requires very precise shot placement. For example, a Nosler 60gr .223 deer hunting bullet penetrates 18.5" and doesn't fragment, but the permanent cavity is less than half an inch across, requiring a much more precise shot than you would need with a bonded core 130gr .270 traveling 300+ ft/sec faster.

http://www.midwayusa.com/product/862243/hornady-superformance-sst-ammunition-270-winchester-130-grain-sst-box-of-20

"it's the degree of cavitating expansion which causes the damage, moreso to surrounding internal organs. Handgun bullets below ~1,000 fps (iirc) generally don't cause significant cavitation, their wounds are often considered akin to being stuck by a dagger or run thru by a thin fencing foil (sword) - the permanent wound cavity."

Yes, exactly. And for all bullet styles, rifles like .243, .25-06, .270, and .30-06 produce more cavitation and more severe wounds than .223 does, whether you are comparing light-and-fragile .223 to light-and-fragile .25-06/etc., or tough bonded-core .223 bullets to bonded-core .25-06/etc. .223 is the least powerful rifle caliber in common use, and it shows.

"After fragmenting, the .223 inside an animal could result in two separate temporary cavities, just like in a human, but greater likelihood than larger hunting rifles for the .223 wound NOT to be fatal, thus resulting in the animal running off mortally wounded & in great suffering."

Choosing a fragmenting .223 bullet instead of a bonded core .223 for hunting small deer would be as stupid as choosing birdshot over buckshot for the same purpose. Fragmenting bullets are for small game and to limit penetration at in-home distances, not for shooting deer. .223 deer loads would be the NON-fragmenting bonded core rounds, like Nosler Partition, Barnes TSX, Remington Core-Lokt, etc., which typically give 18" or so of penetration and no fragmention.

The exact same scenario of a shallowly wounded animal running off would occur if an idiot hunter were shooting fragile loads out of a .243, .270, or .30-06 (or 12ga birdshot, for that matter). A 58gr .243 doesn't penetrate any more than a 55gr .223 does, it just fragments more violently and makes a wider wound.

"Well aware that bullet characteristics are finicky, and that fragmentation is not solely a function of caliber."

Limiting the discussion to modern rifle cartridges, fragmentation isn't a function of caliber at all; it's a function of bullet construction primarily, and velocity secondarily (which in turn depends on the bullet weight chosen within that caliber). A 58gr .243 will fragment more violently than a 55gr .223, more in line with a 40gr .223, even though .243 is a respected deer caliber.

"wiki, eh; most all of this you will concur, but it backs me up: Most handgun projectiles wound primarily through the size of the hole they produce. This hole is known as a permanent cavity. For comparison, rifles wound through temporary cavitation as well as permanent cavitation. A temporary cavity is also known as a stretch cavity. This is because it acts to stretch the permanent cavity, increasing the wounding potential. The potential for wounding via temporary cavity depends on the elasticity of the tissue, bullet fragmentation, and the rate of energy transfer.

Many handgun bullets do not create significant wounding via temporary cavitation, but the potential is there if the bullet fragments, strikes inelastic tissue (liver, spleen, kidneys, CNS), or if the bullet transfers over 500 ft·lbf (680 J) of energy per foot of penetration."

Yes, absolutely. Common handgun velocities are in the range of 850 to 1500 ft/sec, primarily due to the short barrel length (making high powder capacity superfluous). There is some question about whether temporary cavity can affect some tissues above 1100-1200 ft/sec (e.g., +P 9mm at 1300+ ft/sec, or 125gr .357 Magnum at 1600 ft/sec) but at the 2600-4300 ft/sec velocities of hunting rifles, temporary cavity can be a big deal.

What you're missing is that if either temporary cavity size and fragmentation, or velocity, are your criteria for banning rifle calibers, then .223 would be waaaay down the list. You seem hung up on .223 FMJ or light JHP, but go look up the ballistics of .22-250, or .243/.25-06/.270/.308/.30-06 with the light bullets, and get back to me. The little .223 is a rifle round, but its lack of power shows when you compare its terminal ballistics to other common rifle calibers.

You are confusing cavitation with fragmentation.

".. in context I wrote this: .. the .223 was designed for against humans, to incapacitate with grotesque exit wounds & internal fragmentation, rather than a desired quick kill. If cavitation occurs the animal can wander off & be in unbearable pain for days, moreso than with other hunting bullets

If cavitation occurs it would of course add to the incapacitating damage done; other bullets are moreso designed to kill rather than incapacitate as the .223. "

All bullets cavitate; that's what produces the temporary cavity. Rifle bullets cavitate more than handgun bullets. Big rifle bullets like .30-06 cavitate more than small rifle bullets like .223 (and .30-06 can throw a 55gr bullet at over 4000 ft/sec, or a 110gr at 3400, if you want to talk high velocity).

What you appear to be thinking of is fragmentation, which can result in a shallow, nonfatal wound if an inappropriately fragile bullet is used to hunt a big-game animal. And what you don't seem to understand is that fragmentation is a function of bullet choice, not caliber choice. A 55 to 70 grain bonded core .223 bullet designed to stay together on impact will stay together on impact, and penetrate like a scaled-down .270, whereas a 40gr varmint bullet will turn to powder and small fragments upon impact, and penetrate like light birdshot.

Likewise, a 58gr VMAX out of a .243 Winchester at 3925 ft/sec will fragment more violently than any .223, whereas a 100gr Hornady SST out of the same rifle won't fragment at all. So you pick one for coyote hunting and another for deer hunting.

"other bullets are moreso designed to kill rather than incapacitate as the .223."

So .223 Remington should be banned because it's not as lethal as a full-power rifle? Wow. And again, some .223 loads fragment and some don't, just like 9mm, .243, .270, .308, .30-06, and every other centerfire caliber out there; it depends entirely on load choice, not caliber. But with any style bullet, .223 will produce a less severe wound than a more powerful rifle shooting the same class of bullet will, because .223 doesn't have the powder capacity to match the kinetic energy or achievable velocity of the larger calibers for a given bullet mass.

Facts inconvenient to your thesis = "nitpicking".

"What he actually wrote was that it had a 'very high velocity' @ 3,000 fps, which you well know is what imparts high kinetic energy to the bullet, thus making the .223 quite powerful despite its light weight."

Oh, baloney. Plenty of deer and elk rifles can exceed 3000 ft/sec, including that poster's recommendation of .25-06, .270, and whatnot. .22-250 can approach 4300 ft/sec with the same 55gr bullet that you are railing about in .223 at 2950-3000 ft/sec. A .270 or .25-06 can match or exceed the velocity of any .223 load, with more mass, and will create a commensurately larger wound.

The inhumanity of using a small varmint round on a deer-sized animal or larger is that the wound may not be severe enough or penetrate deeply enough to incapacitate the animal, resulting in needless suffering and a wasted death.

"If cavitation occurs the animal can wander off & be in unbearable pain for days, moreso than with other hunting bullets."

Cavitation occurs with *all* hunting bullets above 1500-2000 ft/sec. A .25-06, .270, or .30.06 will produce twice the cavitation (or more) than 55gr .223, because it has more mass and more energy at the same or greater velocity.

"The target shooting aspect is immaterial"

Not for target shooters...which, I'll remind you, vastly outnumber hunters in this country.

"hunting game at longer range impractical; small game a quarter mile away bothers you? a 22 rifle is likely the preferred method for short range."

Then why is .223 Remington the most used varmint hunting round in America?

I'll tell you. Because it has enough energy to make humane kills on small game beyond the 50 yards or so that .22LR will, out to the extended ranges you discuss that require higher energy calibers like .22-250.

Again, you're saying that the top target round in the USA is irrelevant for target shooting, and the top varmint round in the USA is irrelevant to varmint hunting. That is nonsensical.

"your gloss glosses over what you volunteered recently, that the .223 will generally cause more severe damage if it hits a person thru drywall, with more grotesque & serious wounding. Bullet will still tend to fragment. Thus, first author's claim that the .223 is 'less desirable for home defense' is not 'exactly backwards' as you say, but spot on."

No, *you* have it backwards. See the Police Marksman article I referenced upthread. .223 Remington shooting lightweight JHP is *less* lethal after penetrating drywall than 9mm JHP or 12-gauge buckshot, even after a single wall, and is less likely to penetrate multiple walls or exit the structure.

"Here I sorta disagree with author, I think you need between 500 & 1000 dollars to get a bushmaster or ar15, making it an upper class white man's toy"

I suppose $549 is "between 500 and 1000 dollars", but it's hardly out of the reach of a working class adult. You're looking at about the same price as a Savage Trophy Hunter XP bolt-action at Walmart.

"some kind of bizarre status symbol that is hardly ever used constructively or humanely."

The most popular target rifle in the nation is almost never used for benign purposes like target shooting? Uh-huh.

"It is one of the most unused in violent crime or to cause death"

Yep, in spite of its being the top selling civilian rifle in the United States, and one of the most common rifles in U.S. homes. Which makes the obsession with banning it all the more bizarre.

It seems a response to this thread was posted Somewhere Else...

where it would be protected from civil debate. The gist of it:

"the AR15 was a POS for anything but close in combat"

Actually, one of the selling points of the AR-15 platform is that it's not a POS for civilian shooting at 300-600 yards. That's one of the biggest things that differentiates the AR from the Ruger Mini-14 or civilian AK's; the latter are basically 300-yard guns (with the exception of the Mini-14 Target), whereas a rack-grade AR is a 600-yard gun with a suitable optic, and longer barreled AR's are usable for target shooting out to 1000 yards. The AR's design makes it shoot like a bolt-action, and it's easy to swap barrels, free-float the barrel, etc. without needing a gunsmith.

Here's a New Zealand AR owner hitting at 609 yards with a 14.5" barrel and a sound suppressor (yes, New Zealanders own and shoot AR's, and owning a shorter-than-16" barrel and sound suppressor is less of a hassle there than here). The round is slow out of a shorty 14.5" barrel, but accurate:




500 yards with an iScope:



700 yards with a 20" (another Rock River, FWIW):



1000 yards:


"The most popular ARs have 20 inch barrels but good varmint guns have 28-30 inch barrels and are bolt action, a whole different animal from the AR platform."

Not in .223. Most bolt-action .223 varmint hunting rifles have 22" to 26" barrels, because the little .223 case doesn't hold enough powder to take advantage of a barrel longer than 24"; most AR's set up for varmint hunting are 20" or 24".

The 26" to 30" barrels are for more powerful cartridges like .22-250 that can take advantage of the extra length. And as pointed out above, one of the draws of the AR platform is that it shoots like a bolt-action, in terms of accuracy and barrel harmonics.

Remington Model 700 SPS Varmint, 26 inch
Mossberg MVP Varmint, 24 inch
Savage Model 25 Walking Varminter, 22 inch
Weatherby Vanguard S2 Varmint Special, 22 inch
Remington R-15 VTR Stainless Varmint, 24 inch (AR-15 type)


"The longer barrels add velocity (which is crucial to overcoming the 55 grain light weight projectile) and accuracy. "

Not in .223, they don't. Longer barrels add velocity to a point, until the gas has expanded enough that barrel friction overcomes gas pressure and the bullet begins to slow down. The little .223 case doesn't hold enough powder to take advantage of a barrel longer than 26", and some loads start slowing down after 24".

http://rifleshooter.com/2014/04/223-remington5-56-nato-velocity-versus-barrel-length-a-man-his-chop-box-and-his-friends-rifle/

A longer barrel does *not* add accuracy; for a given barrel diameter, a longer barrel is less rigid than a shorter barrel. As long as your barrel is long enough for good velocity (which affects the distance downrange at which the bullet slows to the wobbly transonic zone), adding more length won't help accuracy and may hurt it.

"The only positive input for the AR was the ability to jerk off 10-15 rounds at a running target. Really? That's a good idea? Like you can know what lies past the target and make a humane kill on a running target?"

That is hilarious. You're shooting at 200+ yards, and you think you're going to "jerk off" fast shots? A more measured one-shot-per-second is do-able out to 200 yards or so, but at 600 you'd better be watching and correcting.

And if you can't see what's behind and around the target at 600 yards, you have no business taking the first shot, whether it's a target range or a prairie dog colony. I'm not sure what scenario you're imagining here.

"If you want a good varmint gun try a 25-06. Twice the weight of the .223 and the same velocity. Flat trajectory, not susceptible to windage and with custom loads can exceed 4000 fps. All states accept it for game up to elk."

A .25-06 is a big-game cartridge, not a varmint cartridge. It's a .30-06 deer and elk rifle necked down to 6.5mm caliber for better long range performance, and is about twice as powerful as a little .223, being more comparable to a .270 deer/elk rifle than it is to the centerfire .22's.

Can you use a long range deer and elk rifle like a .25-06 on groundhogs and prairie dogs? Sure! Overkill, but if that's what floats your boat, more power to you. The downsides are that .25-06 costs far more than .223 to shoot, has far worse muzzle blast, and kicks much harder, making it very unpleasant to shoot a couple hundred rounds in a day. For a target rifle, .25-06 would be brutal compared to a .223, for the same reasons of muzzle blast, recoil, and expense.

Cartridge comparison:


Left to right: .25-06, .308 Winchester, .223, .17 HMR, .22LR, .22 airgun, .17 airgun

The guy who was killed for selling loose cigarettes was killed in New York City, not in an NC mall.

I'm pretty sure that if you were walking around with a modern-looking rifle in New York City, you'd be put in a chokehold too...or worse.

A lot of that goes to the difference between NYC's philosophy of government, and the rest of the nation's. We don't have "stop and frisk" here either, and people don't get put in chokeholds for selling fricking cigarettes.

It's a very old law...

and I believe its intent was to regulate the manner of open carry. Of course, given the history of NC gun laws, it was probably written to disallow open carry by people with the the "wrong" amount of melanin in their skin.

Not legal in NC. (n/t)

More scaremongering about centerfire .22's...

Since the ".223 is WAY TOO POWERFUL for civilian use" argument was so glaringly silly, someone has tried the exact opposite argument, basically arguing ".223 is not powerful enough for civilian use, but still should be banned because ZOMG VELOCITY! and its military pedigree" (ignoring the fact that it's based on a civilian varmint hunting cartridge, of course).

http://www.democraticunderground.com/12629188

After a great deal of hand-waving about military automatic weapons and the military utility of 5.56mm in full auto fire, there are some pretty novel claims. To wit:

"Because of the light weight projectile and very high velocity (3000 + feet per second vs 2600 FPS for the M14) many states prohibit the 55 gr .223 round as a humane hunting round."

Wait, just four days ago, you guys were saying that .223 is too powerful for deer hunting and would tear up too much meat if you shot a deer with it, so it should be banned. Now you say 55gr .223 is too underpowered to humanely kill deer, so it should be banned. Which is it?

If you think 3000 ft/sec is "very high velocity", there are plenty of civilian hunting rifles that can exceed 4000 ft/sec with the same weight bullet, or that can throw a bullet two or three times as heavy as a .223 at 3200+ ft/sec. That's because .223's small case doesn't hold enough powder to match the velocity or energy that a bigger case can produce. For example, a .22-250 Remington can throw a 55-grain bullet (same weight as typical .223) at 3786 ft/sec, or a 40-grain at 4224 ft/sec. By comparison, my 16" AR will launch a 55gr at around 2950 ft/sec, if that.

http://en.wikipedia.org/wiki/.22-250_Remington

I also notice you praise .308 (7.62x51mm NATO) as a civilian cartridge. Ummm, guess who developed that cartridge, and for what purpose. And what about .30-06 Springfield, originally designed to kill human beings at extreme range, and capable of exceeding 3400-4000 ft/sec with some loads? Just asking.

"The lightweight projectile and loss of ballistic energy past a few hundred yards making it ineffective for long range target or varmint shooting"

So the #1 varmint hunting cartridge in the nation is useless for varmint hunting. Maybe you should tell these hunters:

http://www.fieldandstream.com/forums/-firing-line/223-vs-22-250 (ummm, yep, that's a hunting site)

Funny thing is, the majority of bolt-action varmint hunting rifles are chambered in .223.

http://www.remington.com/products/firearms/centerfire/model-700/model-700-sps-varmint.aspx
http://www.cabelas.com/product/Mossberg-MVP-Series-Varmint-Bolt-Action-Rifle/1367708.uts
http://www.savagearms.com/firearms/model/25WVCamo
http://www.hyattgunstore.com/weatherby-vanguard-s2-varmint-special-223-rifle.html
http://www.winchester.com/Products/rifle-ammunition/Performance/Varmint-X/Pages/X223P.aspx

Maybe that is true because .223 Remington is a slightly improved variant of the .222 Remington varmint hunting round introduced in 1950, and is even better for hunting small game than .222 is. Yes, .22-250, .220 Swift, etc. kick .223's butt in terms of velocity and energy, but .223 recoils less, is much cheaper to shoot, and doesn't wear out a barrel like the higher velocity choices.

"making it ineffective for long range target or varmint shooting (although very few people participate in 1000 yard competition)."

Soooo, the #1 centerfire target cartridge in the United States is useless for target shooting, too. Do you see the disconnect there? Heck, there's an entire division within F-class long range target shooting (F/TR class) devoted to .223 and .308:

http://demigodllc.com/articles/introduction-to-f-class-1000-yard-competition/

And how about hits at a mile using a custom bolt-action .223?

http://www.longrangehunting.com/articles/shooting-223-mile-1.php

Yes, there are cartridges that carry a lot more energy and velocity at 1000+ yards (6.5mm Creedmor comes to mind, or .22-250, or .300 Win Mag, or .338 Lapua Mag), and yes, .223 is also a great IPSC cartridge. But if all you want to do is punch holes in paper out to 600-1000 yards, you can set up a .223 to do it pretty well, and more cheaply than most.

"Also because of its very high velocity it is capable of penetrating an intruder's body and then interior walls and still inflicting lethal injuries after doing so make it less than desirable for home defense."

This is exactly backwards; .223 Remington with civilian jacketed hollowpoints or softpoints penetrates less in both ballistic gelatin and drywall than almost any pistol or buckshot load.

It is less likely to "penetrate and intruder's body and then interior walls" than almost any other round, centerfire or rimfire, with the possible exception of light birdshot. (I say possible exception because 40gr .223 JHP may even penetrate less than birdshot at close range, but I can't find a suitable birdshot test to compare.)

Don't take my word for it. See Roberts G.K., "Law Enforcement General Purpose Shoulder Fired Weapons: the Wounding Effects of 5.56mm/.223 Carbines Compared with 12 ga. Shotguns and Pistol Caliber Weapons Using 10% Ordnance Gelatin as a Tissue Simulant, Police Marksman, Jul/Aug 1998, pp. 38-45.

Roberts even discounts a lot of lighter .223 JHP and SP loadings as not offering *enough* penetration for routine law enforcement use, although I think that in general, the ideal for home defense is a bit less penetration than might be required for LE use. But if you want to know why law enforcement ditched 9mm carbines in favor of .223 for in-home use, there it is.

And for those who don't have access to a university library, or lack the attention span to read a technical-y academic article (minutiae!), see pictures!

"So, what is it good for? For doing what the military specified; firing a large volume of high velocity projectiles at close range to inflict the maximum number of injuries as quickly as possible."

Baloney. Show me the milspec where the military use of 5.56mm was driven by close range effectiveness over larger calibers. If I recall my history, the 5.56mm decision was based more on increasing the likelihood of hits at longer ranges compared to the then-standard M14. You're quoting gun-control-lobby talking points, not military doctrine. At the time, the U.S. military felt that in any engagement with the Soviets, closing to CQB distances would be a disaster, and hence emphasized accuracy and longer range fire. You do remember that the original M16 had a 20" barrel and target style aperture sights, yes? You do remember that the #1 thing on U.S. military planners' minds was the Fulda Gap scenario, not room-clearing, yes?

"It was designed to military specifications for use by infantry soldiers and paramilitary police officers who have been trained in the use of such weapons."

More handwaving. The .223 Remington is simply a modified civilian varmint hunting cartridge, and in non-automatic civilian rifles, it's simply an improved .222 Remington and a less powerful alternative to harder-kicking, more expensive rounds like .22-250, .243 Winchester, 7mm-08, .270, .308, and .30-06. And since it is easier for a novice shooter to learn to shoot a small, light-kicking caliber well than it is a larger one (which is why .223 is so popular as a first rifle), the argument "ZOMG .223 requires moar training than .308!!!" is downright silly.

In the military context, yes, 5.56mm/.223 allows military automatic weapons to put more lead on target at cyclic rate without uncontrollable muzzle climb. That's irrelevant to civilian non-automatics, just as penetration with military FMJ is irrelevant to civilian softpoints and hollowpoints. For civilians, .223 simply means you can shoot a smaller, lighter rifle with less recoil, less expenditure, and less risk of overpenetration than if you were using a full power rifle, all else being equal.

I'll also point out that some say .223/5.56mm is too underpowered for military use, since the military has to shoot through things, etc. Remember when 5.56mm rifles were derided as "poodle shooters" by Col. Jeff Cooper (USMC Ret.) and others? I think there is some merit to the criticism of .223's lack of lethality at range (see Dr. Martin Fackler, et al), but the real kicker is weight, and modern soldiers are maxed out on weight (body armor, radios, NVG's, support for more effective crew-served weapons). Ditching body armor or advanced electronics so they can carry a heavier-caliber rifle that hits harder would be a poor trade.

Taking Back the Infantry Half-Kilometer (thinks military should switch to a more powerful caliber)
http://www.chuckhawks.com/ar_disgrace.htm (way out of date on reliability issues, but has a point about lack of lethality)

"That's what it is good for."

It's good for civilian target shooting, which is why it's the #1 centerfire target cartridge in the United States.

It's good for varmint hunting, which is why it's the #1 centerfire varmint hunting cartridge in the United States.

It's good for defensive purposes while limiting overpenetration, which is why it's overwhelmingly used in civilian law enforcement patrol rifles and why it's the #1 choice of U.S. homeowners for defensive carbines.

Hand-waving about military automatic weapons shooting military full metal jacket ammo has absolutely nothing to do with the merits of .223 Remington as a civilian rifle cartridge. It's by far the most used civilian rifle round, and for very good reasons.

"Yet anyone with a few hundred dollars can walk into Walmart and buy one without training or instruction. There is something wrong with this system."

Just like any other civilian rifle, including those that are far more powerful and more lethal (which is most of them). Of course, you just want to keep as many guns as possible out of the hands of U.S. gun owners, which is why you're fighting so damn hard to outlaw the least misused class of weapons in America.

.223 Remington is the least powerful civilian rifle cartridge in common use (except for 5.45x39mm), but that doesn't mean it's not a great civilian cartridge, and all the handwaving in the world won't change that.
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