Recently I tested 55 grs. bullets of 223 remington, shot through an 20 inches AR barrel, against about 6 mm. of iron at a distance of 25 mt.

The bullets pierced the metal like butter.

So I was asking ot myself how true were the conclusion of the FBI, reported by italian gun magazines, that .223 remington was the most suitable for CQB and entry teams because there is no ricochets and no overpenetration.

Anyone with my same doubts?

As a general matter, after they hit something they start to break up pretty quickly.  M193, in any event, will start to get useless after about 5-10 feet from a good impact.  This is especially true of CQB because the velocities are up around 3100+ fps.  The best thing for you to do is go buy a bit of drywall and try it out.  Two sheets of drywall would simulate pretty well any standard interior wall without stud.  Put a pumpkin 5-10 feet behind a 6" spaced pair and see if you can do it much harm.

Ditto what tatjana stated.
If what you read was the FBI report, or a detailed summary, you will notice that the best results were not FMJ.  If you perform the test tatjana describes, use JHP, TAP, or any other high performance bullet.

Another test preformed here was use plastic milk jugs (1 US GAL or equivalent).  You will need several filled with water.  Place them in a row.  Use FMJ first.  (have SEVERAL lined up for this one).  Shoot.  Notice how many are damaged.  Replace said damaged milk jugs.  Use a JHP, JSP, ect and repeat test several times.  The best results were from TAP.  1-milk jug dead, second one had a ding, but no water leaking out.  Our carry ammo: 1st milk jug, dead; second seriously wounded; third, unharmed.
Our duty ammo is Federal .223 Premium 55 grain Sierra Game king BTHP.  Good, but not the best.
Hope this helps.
Art in KY

PS My carry AR15 (16" Bushmaster) with this ammo is LESS likely to over penetrate then my Glock Model 22, .40 with 180 grain Hydro-Shock.(sp?)

I am not responsible for misspelled words while the spell check is down.

My test involved 7 sheet rock walls each with 4"of fiberglass insulation.

Ammo:
Federal 55gr hp.
Federal 69gr match.
Federal 9mm hp.
My Custom load.

And 6 PPD officers witnessed test.
AR-15,16" bbl
MP-5

Penetration test
55HPs 7+ walls
69match 5walls (imediate tumble)
9mm MP-5 7+ walls
My Custom load 2walls and 2+walls.

www.moaammo.com  

I love the .223 so don't get me wrong,  but as for use against a man sized target I think it is junk. Want a good read from an unbiased source? Read "Blackhawk Down"....pat

Quoted: I love the .223 so don't get me wrong,  but as for use against a man sized target I think it is junk. Want a good read from an unbiased source? Read "Blackhawk Down"....pat

That's not what my (very) preliminary gelatin tests suggest.  I'll put it this way, I was EXTREMELY impressed with the penetration, wound channel, and it's explosive fragmentation at 15 feet. (from a 20" barrel)

There will be much more information to follow on this in the next few months hopefully.

Until, I will say no more.

Quoted: Ditto what tatjana stated. If what you read was the FBI report, or a detailed summary, you will notice that the best results were not FMJ.  If you perform the test tatjana describes, use JHP, TAP, or any other high performance bullet. Another test preformed here was use plastic milk jugs (1 US GAL or equivalent).  You will need several filled with water.  Place them in a row.  Use FMJ first.  (have SEVERAL lined up for this one).  Shoot.  Notice how many are damaged.  Replace said damaged milk jugs.  Use a JHP, JSP, ect and repeat test several times.  The best results were from TAP.  1-milk jug dead, second one had a ding, but no water leaking out.  Our carry ammo: 1st milk jug, dead; second seriously wounded; third, unharmed. Our duty ammo is Federal .223 Premium 55 grain Sierra Game king BTHP.  Good, but not the best. Hope this helps. Art in KY PS My carry AR15 (16" Bushmaster) with this ammo is LESS likely to over penetrate then my Glock Model 22, .40 with 180 grain Hydro-Shock.(sp?) I am not responsible for misspelled words while the spell check is down.

I'd have to digagree.
I shot at an older style (purged) propane tank.
At about 20-25 yards, 9mm wouldn't come out back. 185 grain .44 meg wouldn't go out back!
.44 meg almost exited out back. 9mm didn't come close.
.223 out of my 20" bushy, all 30 rounds exited, leaving a 3" exit "wound".
I know metal is a different test then wood/sheetrock, but its got to say something!

Quoted: I love the .223 so don't get me wrong,  but as for use against a man sized target I think it is junk. Want a good read from an unbiased source? Read "Blackhawk Down"....pat

The problem with the 5.56 in Blackhawk Down was that they were using ss109's (designed for M16A2 use), in short barreled CAR's which did not impart sufficient velocity for the bullet to effectively fragment.

Paolo...pisan...tatjana is beautiful and she has brains, A deadly combination I'm sure you would agree with. But, Imbroglio has it right. In combat, velocity is King. I posted a chart here www.ar15.com/forums/topic.html?id=69198&page=2. Intial means a small hole. Loop hole means nothing for this discussion, skip it.
Ciao, gumba

For non-miltary anti-personnel use, soft point ammunition might be the better idea.  

The obvious difference between metal penetration and tissue penetration (or over-penetration) is the energy-dissipation properties of the materials v. the projectiles being tested.

Quoted: I know metal is a different test then wood/sheetrock, but its got to say something!

The instructor stated he used water to better simulate human flesh.  Ballistic gelatin would have been ideal.  Curious, what ammo was the .223?
Art in KY

Quoted: Quoted: My test involved 7 sheet rock walls each with 4"of fiberglass insulation. Ammo: Federal 55gr hp. Federal 69gr match. Federal 9mm hp. My Custom load. And 6 PPD officers witnessed test. AR-15,16" bbl MP-5 Penetration test 55HPs 7+ walls 69match 5walls (immediate tumble) 9mm MP-5 7+ walls My Custom load 2walls and 2+walls. www.moaammo.com   From what distance?

Left 15 feet for the chrono and 1ft behind that approx 16 ft total.gj.