there are plenty of pictures of cavity wounds for the the 5.56mm & 7.62mm rounds, but I have never seen any of these for the handgun rounds.

the reason I ask, is because the people here keep saying 5.56mm is so good for close quarters, because it causes large cavity wounds, low chance of over-penetration, but good chance of body armor penetration.  but it seems like the .45 ACP and 9mm have problems with over penetration (which would suggest to me that they also do less fragmentation and cavity wounding), have less-controllable recoil, and less ability to penetrate body armor.

now, all this makes me very confused as to why gun companies do not use the 5.56mm caliber in SMG very often.  in handguns, I understand, because the bullets would be too long to fit in the handgrip.  But in most SMG, like the MP5, the magazine is not in the handle, so length of the bullet is not much of an issue.

it seems that the majority of SMG's are not designed in the 5.56mm caliber....the main ones that I can think of are the HK53 and G36C.  but the HK53 is certainly less popular than the MP5.  can somebody explain the full picture to me so I can make some sense of why these decisions are being made?  thanks!

There are pictures available for either of these rounds, but the're unimpresive .45" and .38" holes bored straight thru the target.

If the bullets expand they get about 50% bigger at best.

Pistol velocity bullets produce no measureable temporary cavity so there's no large cavity to shred with bullet fragments as 5.56mm Ball does.

Using an MP5 when the M4 Carbine is available is a major mistake folks are finally realizing.  

-- Chuck

wow, how can Heckler & Koch not know about this?

I'm sure they do, thus the reason for the HK53 and the newer G36K and the G36C.

Plus, I seem to recall that the MP5 is no longer produced (replaced by another pistol cal the UMP...the 53 is also discontinued, IIRC).

It's all about $$$.  If departments want pistol cal carbines, somebody will make them.  They might want them due to a lack of understanding ballistics, or it might be for liability reasons.

These are ball loads but but you get the idea. Damage larger than bullet diameter is rare.
[img]http://www.firearmstactical.com/images/Wound Profiles/45ACP 230gr FMJ.jpg[/img]

[img]http://www.firearmstactical.com/images/Wound Profiles/9mm US M882.jpg[/img]




Muzzle blast, muzzle flash and low muzzle velocity. They can all be alleviated but at an added cost. Plus, the stubby ARs don't demonstrate the same level of reliability as the rifles, and even carbines, do.

Add in that we, the faithful, are still educating the few that 9mm/.45 out an SMG isn't any more effective than the same out of a pistol and .223 is "too much gun" for indoors/LE and you've got the current situation.

[bored kode]

thanks a lot for those pictures Tweak

im having difficulty making sense of your comment



wouldn't a .223 have higher muzzle velocity? isnt that the idea?



do you mean a cash $$ cost?  cost of what? a flashhider?



interesting.  why is that?



seems like all of your points support that the .223 is a bad round for cqb...then you conclude by saying it is a good round, so im a bit confused here as well

.223 has a higher muzzle velocity than pistol rounds. From a short barrel it has a lower muzzle velocity that that required for a lot of loadings to work terminally. Many low velocity, or otherwise non fragmenting, .223 rounds are as effective as a .22RF

Problem:          
Muzzle blast.
Solution:
Ear protection, eye protection.
Failing:
Limited hearing, limited field of view
Solution:
Suppressor
Failing
Cost, licensing, public perception.

Problem:
Muzzle flash
Solution
Low flash loads.
Failing
Cost, lowered case capacity.
Solution
Improved Flash suppressor
Failing
Cost
Solution
Suppressor
Failing
See above

Problem:
Low muzzle velocity
Solution
Improved loads
Failing
Cost, availability, transportability.

The stubby guns, like the carbines, are working on a steeper pressure curve and cycling harder. They break parts more often and malfunction at a higher rate. The AR15 is a system, the further you get from the original the more finicky it will get. The problems can be dealt with but at an added cost.

The .223 round, when properly set up, is an excellent round for CQB, it beats any pistol round handily. It has downsides that one needs to aware of though.

I read an article put out by Olyarms ([url]http://www.olyarms.com/223cqb.html[/url]) citing FBI testing that concluded that 5.56x45 caliber would still provide adequate fragmentation (and thus stopping power + not overpenetrating) with barrel lengths 10-11 inches or greater.  This suggests that the G36C and HK53 would not be adequate, suggesting to me, the Colt M4 Commando (best suited SMG size .223 carbine I know of)  and G36K (which has a long enough barrel to maintain necessary velocity for large wound damage).  Both of which are very similar in internal barrel length and overall length.  

However, I think it would be better if a more compact weapon were used.  This has led me to consider the P90 as a superior weapon, because it seems to overcome the main disadvantages of the M4 commando/G36K.

[b]recoil:[/b] P90 wins. 60% of the recoil of a 9mm SMG like the MP5.  M4 Commando would have greater recoil than a 9mm smg.

[b]ROF:[/b] P90 wins or ties with M4. 900 RPM (compared to 800 of the MP5, 750 from G36K, 750-900 RPM in colt commando).  RPM is crucially important in a CQB situation where the suspect would be encountered at close range only and whoever hit first would likely win.  I dont know why the colt has a variable RPM listed...is it 750 or 900 really?

[b]compactness:[/b] P90 wins. 19.8 inches overrall length, compared to 26.8 in Colt M4 Commando, 24/33.8 inches of the G36K.  the G36K's most shortened length is also not fair to compare because recoil would be more difficult to manage without a stock.  the M4 still could be shouldered in its most compact form.  so the p90 definitely wins here.

and It also seems to overcome the disadvantages of a conventional SMG:

[b]fragmention/stopping power/overpenetration:[/b] P90 beats 9mm, and ties or comes close to tieing with .223.  virtually no overpenetration, large cavity wound damage, due to back-weighted nature which causes tumbling. it also probably exerts similar but reduced fragmentation compared to the .223.  compare this to .45/.40/9mm/10mm which will more likely penetrate and not fragment.

[b]body armor:[/b] P90 beats other SMG, loses to .223. the round is slightly larger(5.7x28), which is oging to make armor penetration more difficult than the .223.  it also has lower velocity which wont help.  From what I've read, .223 can penetrate body armor but then has trouble causing wound damage.  Given the lower charge of the SS109, I wonder if it would be capable of causing significant damage to a suspect after passing through body armor.  but the company claims that it can somehow peentrate 48+ layers of kevlar.  I dont know how this compares to the .223, or how kevlar compares to other body armor types.  It may or may not be adequate, i dont know enough on this subject.  

[b]other advantages of p90:[/b]
50 magazine capacity, non-protruding magazine
lightweight integral red dot which can be replaced if desired

[b]disadvantages to p90:[/b] large size of magazine does not fit into tactical vest, potentially slower magazine changing time, more difficult to fire in non-shouldered firing positions, thumbhole may not fit some users!

If anyone can offer opinions on my conclusions here, or produce pictures of SS109 cavity damage from the P90, or offer information on SS109 armor piercing capabilities compared to .223 armor piercing capabilities, I would really like to hear from you.

Most body armor will stop pistol ammunition.  Rifle ammo will zip right through at close range unless plates are added to the vest.  You get the picture.

MM

Wow some pretty 'conclusive ideas' without a shred of evidence to back it up?  Where do you get the idea that the P90 ammo fragments or even comes close to 9mm (let alone 5.56) in terms of wounding potential?

Doc Roberts covers it well here (including cites of MANY studies done on the round).
[url]http://64.177.53.248/ubb/Forum78/HTML/000050.html[/url]

No overpenetration because it UNDERpenetrates.  Badly.

And sorry, but the wound channel resembles a .22 Magnum.  You're seeing a TEMPORARY cavity in gel photos.

Forest,

I am purposely trying to jump to my own controversial conclusions specifically becaise I recognize my ignorance in the subject.  The only way for me to know if I am understanding something correctly is to pick it apart and make conclusions from it, and if somebody corrects me, then I realize I was wrong and learn something.  

However, in my post, I did not say that it had good fragmentation, but assumed that it had large wounds due to the fact that a) it did not overpenetrate, so all of the force of the bullet must be stopped within the person and b) the bullet is designed with a backweighted nature to tumble.  What I said in terms of fragmentation was that it was likely to fragment like the .223 only less so due to it's larger caliber and lower velocity.  i was concerned about the fragmentation potential but took on faith what the FN website said about it.

brouhaha,

that was my biggest fear with the SS109 ammunition, the fact that it lacked the charge of the 45mm cartridge and had a larger caliber further reducing velocity.

I assure you, I am not seeing a temporal stretch cavity in gel photos.  I can assure you this because I havent seen any gel photos, but I would like to!  However, your statement perplexes me because I believe Doc Roberts or somebody else on the BMT/RBCD discussion said that gel would not show temporal cavity damage, just regular cavity damage, and that's why BMT ammo did not look as good in gel as on meat.

Now I am getting mixed information, because the FN website says that their ammunition has excellent stopping power, and you're saying that it underpenetrates and has insuficcient stopping power.  I recognize that a company would tend to bolster its own image but I dont want to take this information on faith from either source...can you direct me to the data that leads you to the conclusion that the FN ammo is inadequate?

What force?  Doesn't it weigh 31gr?  It has NO momentum behind it.





Because manufacturers never bend the truth to sell their wares?



I'm not sure I understand you here.  You mean the .45 ACP?



They're around.  I'll see if I can dig some up.




I don't know who said that, but I can definitely see the temp cavity in gel photos.  Particularly the shots Tatja and I have done.



Read Forest's link above.  While on that website, do more searches for the 5.7 and you'll see.  If you can, read the IWBA articles that Robert's cites in his post on that thread.

I NEVER trust the manufacturer...unless it's myself.

There is also a post on the General Forums here:
[url]http://www.ar15.com/forums/topic.html?b=1&f=5&t=212064[/url]

There are multiple threads tacked to the top of the ammunition forum which will answer a lot of your questions.

There is the [url=http://www.ar15.com/forums/announcement.html?b=3&f=16&id=178]Best of B&T Ammolabs[/url], [url=http://www.ammo-oracle.com]Ammo Oracle[/url], and finally [url=http://www.ar15.com/forums/topic.html?b=3&f=16&t=164814] Wound Ballistics Articles by Dr. Martin Fackler[/url].

One important thing in regards to a bullet tumbling - I'm surprised so many people think a bullet keeps tumbling ad nauseam or that there is some magical thing that happens. The bullet - in the case of a conical rifle bullet - will tumble ONCE, 180 degrees to travel with it's center of mass forward (its base). RN bullets, like the pistol bullets in Tweak's pictures, may not tumble at all. Even so - there's nothing magical about tumbling. The permanent wound cavity becomes larger for a short distance while the bullet yaws 180 degrees.

do you mean 31 grains or 31 grams?  i am not sure how heavy it is.  31gr sounds awefully light.  i was not aware that grains were specifically a measure of weight.  if you mean grams, then i dont know how to compare that because i dont know the gram weight of other bullets.



like i said, i have not overlooked that possibility.  but i tend to assume that there is some merit to what a company says, and they are blatantly bragging about this feature, so i think its worth looking into.



no.  I am comparing the 5.7x28mm FN round to the 5.56x45mm NATO round.  I am assuming that the slightly larger caliber will result in slightly lower velocity.  Recognizing that the 5.56mm caliber required a lot of velocity to cause substantial fragmention, I was concerned that by shortening it from 45mm to 28mm it would lack the sufficient velocity required to fragment as the 5.56x45 does.



i would appreciate that



noted




alright i will read those as soon as i have time

thanks for those links.  after reading that, I no longer question the inefficiency of the SS109 round.  

brouhaha, I agree with you.  You seem to have misread my post.  I said that the 5.7x28 was a larger caliber with less power than the 5.56x45, and that BOTH of these factors would cause the [b]5.7 to have a lower velocity[/b] than the 5.56.

I realize this is getting a bit off topic in terms of ar15, but I have nowhere else to ask, so i will just continue hopefully its not a problem.

you guys have explained why the p90 is no good.  so i looked around for the shortest 5.56 carbine...and that is the fn f2000.  not only is it the shortest, but it has a much longer inner barrel than many larger carbines including the M4 commando.  the weight is comparable.  can anyone think of any problems with this rifle?  it seems that for these reasons it would be the best suited weapon for unsilenced CQB.

The reason I misunderstood is because both the 5.56 and the 5.7 use .22cal bullets.  It's just the name that's different.  Kinda like the Swiss version of the 5.56 is called the 5.6x45.  The .308 and .300 Win Mag can also use the same bullets.  So do the .38 and 357 Magnum.  

It's a marketing thing.

I thought you were referring to the heavier bullets of the 5.56.

brou,

well then...that certainly is ridiculous.  why would FN do such a thing.  WHY.  (this is a rhetorical question)

Troy,

gotcha.  thanks for explaining that.

so what do you guys think of the F2000?

the maryland shooters site has a very helpful table relatign barrel length to muzzle velocity to 2700 & 2500 velocity range (reliable/maximum fragmentation range).  however, it only goes for 20-11" barrels. Does anyone know of a larger table that could show muzzle velocity over a larger range of barrel lengths? (specifically down to a 9 inch barrel)

Not to mention that a FA 9mm is cake to control vs. a FA 5.56 in such a short barreled weapon.

Well, from personal experience, a 9mm FMJ shot into the leg at point blank range (est 1000fps), w/o hitting bone did little damage.  The exit hole was less than the diameter of my pinky fingernail.

MG

You start getting below 11" barrels and you won't be seeing fragmentation for M193 & M855 (the rounds the table is setup for).

However other rounds have lower fragmentation thresholds.  If you're going to a 9" barrel you'd want to look at the heavy OTM bullets and only expect fragment at really close ranges.

Forest,

I am aware of this.  it is because it needs at least 2500 fps to fragment.  the reason i want the 9" velocity data is so that I can make a more accurate plot of the data so I can see if barrel length is linearly related to muzzle velocity or logarithmically related.  also, I want to see if my assumptions about the G36C -- that it would not fragment at the muzzle -- were precisely accurate, or know exactly what range it would fragment at, be it 40m, 10m, or what.  I also want to see data for longer barrels so that I can determine the fragmentation range of my 24" bushmaster.

Thinking about the FN ammunition system...it seems that they had a really good idea with the P90, but they just made a tiny mistake.  

The idea: put the 5.56x45mm bullet in a bullpup carbine that is the same size as a conventional SMG.  then, to eliminate the excess recoil + muzzle flash + noise that would be expected by putting a rifle round in a small gun, they said, lets just reduce the powder to the optimum level for our P90 barrel length so that it performs ballistically exactly the same as a 5.56x45mm in a 9" barrel but without the excess recoil.

The problem: they made it too compact, a 9" barrel will not allow the 5.56 to perform adequately.  

The solution: if they lengthened the barrel just 2 inches, they could then have all the fragmentation advantages of the 5.56 in SMG size without the recoil.  The question I am wondering, is, can this be a possible modification?  Looking at firing photos of the P90, I see significant muzzle flash, which suggests that maybe if you modified the inner barrel to be 11", it would still have enough charge to shoot at the same speed as a regular 5.56x45mm out of an 11" barrel.  if this were the case, it seems like this gun would step up to a whole new level.  does this make sense to the experts out there?