Comments I would like verfication on


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InfernoMDM
July 28, 2005, 11:56 PM
Can someone reply to the below info. From what I can tell from tests, info etc. I cant believe this guy is right. Can someone verify or disprove this for me? This comment was about CQB and 9mm vs the 5.56 penetration.

"There is a good reason most SWAT teams have switched from 9x19mm HK MP5's to 5.56x45mm AR15/M16's for entry/CQB.

A 9mm from a carbine-length barrel has a tendancy to over penetrate.

On the contrary, a 5.56mm with a velocity in excess of 2700fps (achievable at CQB range from an 11.5" barrel) will break apart at the cannelure upon entry (often breaking into even smaller pieces), transferring it's kinetic energy within the body, thus vastly reducing the chances of over penetration.

I suppose if there's no concern for what might be behind your target . . . "


"Actually, ball ammo has just as great a chance of fragmentation at CQB range as other varieties, sometimes more."

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Cesiumsponge
July 29, 2005, 12:19 AM
It's been shown in informal tests (Box Of Truth) that even pistol-length barrels firing a pistol round will on average penetrate on equal or superior grounds compared to VERY specific 5.56mm loadings using drywall as a test medium.

Those specific loads from 5.56mm that penetrate less than pistol loads are frangible and/or hollowpoints of less mass (40-50gr range) and higher velocity (3000fps+), therefore designed to break up very rapidly. Pistol rounds like 9mm and .45 tested outperformed the 5.56mm in jp/frangible offerings on drywall medium. While those 5.56mm loads mentioned will penetrate less drywall and might sound good, its performance on a human subject are not as well documented so it might be risky in stopping power. That same source (BOT) tested M193 which showed typical "rifle overpenetration" effects that exceeded pistol rounds tested.

Yet, M193 and M855 (both FMJ loads) offerings have been very well documented to realiably fragment at the cannelure at a certain key velocity (which I don't have handy). Any velocity above that leads to increasing fragmentation and subsequent damage. Any velocities below that greatly reduce it's effectiveness as it will not fragment and leaves a simpler wound channel.

Interestingly enough on sand-filled targets, all rifle loads penetrated less than pistol loads.

The simple answer to your question is "it depends". Specific ammo types will do what they're designed to.

Majic
July 29, 2005, 12:20 AM
On the contrary, a 5.56mm with a velocity in excess of 2700fps (achievable at CQB range from an 11.5" barrel) will break apart at the cannelure upon entry (often breaking into even smaller pieces), transferring it's kinetic energy within the body, thus vastly reducing the chances of over penetration.
Where in the world was this heard from? First not all 5.56mm bullets have cannelures. Second unless it's a frangible bullet it won't break apart. Bullet jacket design have developed beyond the stone age. Now an expanding bullet will expand not far from entry and yes it could (and I said COULD) shed some of the lead core as it continues to penetrate, but a FMJ will hold it's shape unless it hits a bone. Then it may deform, but it still won't break a part.
To put it politely, that is the most uninformed statement I have ever heard.

Cesiumsponge
July 29, 2005, 12:26 AM
Second unless it's a frangible bullet it won't break apart.
...but a FMJ will hold it's shape unless it hits a bone.

Simply untrue in certain cases. Specifically, M193 and M855, mil-spec ammunition from Federal and Winchester, have shown overwhelming regularity in fragmentation at the cannelure at required velocities, which IS a present and required feature on M193 and M855. There are 55Gr FMJ which might get compared to M193. Unless its a contracted ammunition, it's simply a patterned bullet design or clone, or simply a bullet in the same weight category. Many have shown contrary results to M193. Wolf makes a 55gr FMJBT that's similar. However the copper jacket is thick enough that it won't fragment.

This following link is one of the best compilations for this information: http://www.ammo-oracle.com/body.htm

http://www.ammo-oracle.com/images/wund5.jpg

^^^ That is M193 tested in calibrated ballistic gelatin. You can see velocity vs fragmentation.
http://www.ammo-oracle.com/images/m193frag.jpg
^^^South Afican mil-spec M193 recovered from calibrated ballistic gelatin test @ 3150fps. Fragmented big time.

http://www.ammo-oracle.com/images/extracted.jpg
^^^ Wolf 55gr FMJBT @ 2885fps. Fast enough for M193 to fragment, but the Wolf remains in one piece.

Majic
July 29, 2005, 12:38 AM
have shown overwhelming regularity in fragmentation at the cannelure at required velocities, which IS a present and required feature on M193 and M855.
Doesn't that say it's a frangible bullet?

Cesiumsponge
July 29, 2005, 12:44 AM
M193 is a NATO-spec 55gr FMJ and M855 is a NATO-spec 62gr steel-cored "penetrator". Both use a true lead core w/ copper jacket (with the addition of a steel section in the M855. Neither are listed as frangible. I don't know if the ribbed cannelure was designed specifically for fragmenting the copper jacket or it was a bonus. Either way, a cannelure doesn't turn an FMJ into a frangible round.

Federal makes a specific "U.S.G.I. 50 GRAIN BULLET REDUCED RICOCHET LOW PENETRATION UNITED STATES GOVT. ISSUE. IN SEALED G.I. AMMO CANS" according to www.ammoman.com

Frangible ammo uses a matrix of metal powder or particles bound in resin or whatever other method of binding that creates a solid, but disintegrates on impact. It is like beating someone in the head with a sack of wet sand. They also have prefragmented ammo, which I guess is like beating someone with a sack of quarters.

InfernoMDM
July 29, 2005, 12:59 AM
So generally speaking is the 9mm or 5.56 more apt to going through someone?

Cesiumsponge
July 29, 2005, 01:09 AM
As I mentioned:

The simple answer to your question is "it depends". Specific ammo types will do what they're designed to.

You'd have to be much more specific. 5.56mm runs the gamute of less-than-9mm penetration to much-more-than-9mm-penetration. 9mm and 5.56mm ballistics and penetration would also depend on the type of ammo and the velocities encountered.

It's kind of like asking: Is a 4-cylinder faster than V8. Yeah, under specific circumstances, but not always (almost never :neener: ).

444
July 29, 2005, 01:17 AM
Ammunition need to be tailored for the purpose you intend to put it to.
There is 5.56 ammo that might not even penetrate a single sheet of drywall (frangible) and at the other end of the spectrum there is armor piercing. As a civilian in the United States, you can use whatever ammunition you want to use.
Most of the knee jerk posts made on the internet in regard to 5.56/.223 ammo is referring to military ammunition. Military ammuntion faces an impossible task. Penetration is VERY desireable for military ammunition. But, having a bullet expand and/or fragment is also very disireable. Having a bullet with the ability to do both is all but impossible. So, you comprimise and end up with a bullet that doesn't do either task real well. This information does me no good at all. I have owned at least one AR15 since the early 1980s. At present, I own more than 10 as well as two bolt actions chambered for the same cartridge. I have NEVER fired a single round of military issue ammo out of any of them. The only military issue ammo I ever fired was when I had no choice because I was in the military: I fired what they handed me. The terminal effects of military ammo is as valuable to me as yesterday's newspaper.

bogie
July 29, 2005, 09:35 AM
Hmm...

I, for one, can sorta understand the 5.56 for houseclearing...

Why?

I'm guessing that the folks DOING the clearing are wearing some darn good hearing protection. Wearing goggles. All that stuff.

You pop a hot-load .22 rifle round in an enclosed space, and it's the next best thing to a flash-bang. You don't have to shoot the bad guys - they'll be holding their ears and trying to crawl under the furniture.

And if you're shooting pre-fragmented 40 grainers, well, they probably won't go through more than a couple of layers of gypsum board.

Cannelured rounds tend to be fmj solids or soft points, and I wouldn't count on 'em breaking up reliably. I'd rather see "dust" rounds specifically made for the job. And you're still going to have to worry about jacket pieces zipping around.

Now, if it was me, I'd just go with flash bangs, and a suppressed .45.

Hawkmoon
July 29, 2005, 10:13 AM
It also depends on the weapon. If you can find it, read up on the AR-15 and M193 and M855 ammo on a site called the Ammo Oracle.

Both the standard military AR rounds tend to break apart at entry. They are not frangible rounds, but it high velocity they tumble on impact, and the centripetal force generated by the tumbling causes the jacket to separate at the cannalure.

BUT ... (big "but") this is for rounds fired from a standard 20" barrel. Among the complaints about the M4 carbines in the sandbox is that the shorter barrels don't produce sufficient velocity to cause the tumbling and fragmentation. Which means you might as well be shooting .22LR (or maybe .22 magnum). The effect is even worse through an 11-1/2" barrel.

I would say that article is a bit wide and short of the mark.

444
July 30, 2005, 02:03 PM
That last post was strictly about shooting military ammo. If you are NOT shooting military ammo ........................

I am not trying to be a jerk, but most of the stuff you read on the internet about the 5.56 round is assuming we are ONLY talking about military ammo. They will refer you to pages that discuss the performance of military ammo. If you are not using military ammo then that information is not informing you of anything germaine to you.
Whether or not a bullet fragments, expands, tumbles etc. is a function of bullet design. A given bullet will perform as designed when it is fired at the design perameters. Military ammo is designed to do certain things at certain velocities just like every other bullet. If the performance you want doesn't occur at the velocity you want, then don't use that bullet. Find a bullet that does what you want it to do.
For the VAST majority of civilians, military ammunition doesn't do what we need/want it to do for most of our uses. If you want really super accurate ammo, military ball ammo isn't it. If you want violent fragmentation, military ammo isn't what you are looking for. On and on and on. Military ammo is an attempt to do everything the military needs in one bullet. As civilians we don't need one bullet to do it all. We can pick and choose bullets to do whtat we want, and if our needs change we can change bullets or cartridges or weapons.

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