5.56x45 effectiveness from short barrels.

[Podmonkey]

Pod. If I shoot you in the chest with a burst from an MP5, your chest isn't going to quote energy numbers. Vitals will be struck and you will die.

You don't have such reservations with a pistol now do you? I'm sure you are 100 percent confident in your pistol's ability to kill someone with proper shot placement. That same shot placement is required for a .223 as with the 9mm. But for some reason, it isn't enough if it has a longer barrel and a 9mm when it was previously adequate from a 4 inch barrel.

Remember that thread I did recently? Where that robber took numerous hits from pistol rounds seemingly without effect? I put up with the 9mm because I can carry something like a G19 very discreetly on my hip, but if I have the bulk of a proper long gun I think I want more power.
Maybe I should get the .308 pistol?
I'm not a huge fan of the MCX frankly. SIG is having trouble with their QC lately.

 

[Marine Cpl]

Remember that thread I did recently? Where that robber took numerous hits from pistol rounds seemingly without effect? I put up with the 9mm because I can carry something like a G19 very discreetly on my hip, but if I have the bulk of a proper long gun I think I want more power.
Maybe I should get the .308 pistol?

Sometimes hollow points do that. They don't penetrate enough in some cases. That's why I won't use them.

 

[Podmonkey]

And again, its a

Sometimes hollow points do that. They don't penetrate enough in some cases. That's why I won't use them.

I don't think they were using hollow points. I bet they were using ball ammo.
I have to imagine that a 223 soft point at 2,300+ FPS will penetrate.

 

[Marine Cpl]

And again, its a

I don't think they were using hollow points. I bet they were using ball ammo.

Those 2 women? My guess is an underpowered handgun using hollow points. Vitals weren't struck. Insufficient penetration. If struck, it wouldn't matter if it was via a pistol or rifle. A struck vital is a struck vital.

 

[meketrefe]

We are talking about literally twice the energy for a 5.56 out of a 7.5" barrel vs the 9mm.

One distinctive advantage is not the energy but the capability for the round to defeat hard barriers over any other
pistol caliber or other rifle rounds like the 7.62x39, 300 whisper/blackout, etc...
So by reducing the speed and increasing the noise, blast and heat drastically one reduces the effectivness of this
round in one of the primary advantages then energy doesn't matter that much because many rounds pistol
and rifile will do the job if there is no presence of certain barriers or body armor.
Speed is the key, not energy. Also momentum and terminal design is more important than energy.
Energy alone is an indicator but not the only one and it might mean something or nothing given the role.

Again, rethink the size of barrel. I suggest this in good faith and based on the feedback not just from
my experience but from others. The size difference in practical terms is almost insignificant. 3-4 inches
here is a good return on investment.

 

[Podmonkey]

Those 2 women? My guess is an underpowered handgun using hollow points. Vitals weren't struck. Insufficient penetration. If struck, it wouldn't matter if it was via a pistol or rifle. A struck vital is a struck vital.

Looked like a .38 revolver and some indeterminate automatic.

 

[Podmonkey]

One distinctive advantage is not the energy but the capability for the round to defeat hard barriers over any other
pistol caliber or other rifle rounds like the 7.62x39, 300 whisper/blackout, etc...
So by reducing the speed and increasing the noise, blast and heat drastically one reduces the effectivness of this
round in one of the primary advantages then energy doesn't matter that much because many rounds pistol
and rifile will do the job if there is no presence of certain barriers or body armor.
Speed is the key, not energy. Also momentum and terminal design is more important than energy.
Energy alone is an indicator but not the only one and it might mean something or nothing given the role.

Again, rethink the size of barrel. I suggest this in good faith and based on the feedback not just from
my experience but from others. The size difference in practical terms is almost insignificant. 3-4 inches
here is a good return on investment.

The Galil only comes in 7.5" and 16" lengths unfortunately. I already have a 16" one.

 

[meketrefe]

And again, its a

I don't think they were using hollow points. I bet they were using ball ammo.
I have to imagine that a 223 soft point at 2,300+ FPS will penetrate.

Most rifle rounds at 2200 fps loose most of their capability to produce massive shock.
It is a matter of the terminal design and ballistics. After that most bullets rely solely in
wounding potential alone. This is what pistol rounds do, they compensate for their lower
speeds by introudction section and more aggressive terminal desings like solids and bonded
hollow points.
That is why the 30 caliber was phased out for military use because the rounds are not that
effective at hard barrier and then range is limited to impact above 2100-2200 rounds.
This is the biggest limitation of the 30 carbine and blackout and others.
Small for caliber, low sectional density and slow speeds is not the most desirable so why
then compromise from pistol if one is abandoning those advantages of the 5.56?

 

[meketrefe]

The Galil only comes in 7.5" and 16" lengths unfortunately. I already have a 16" one.

The galil is limited by design too. It has been phased out. Continues to be a good gun but
I would try to take maximum advantage of both platform and modern rounds.
Again, this is me. you might have ohter things in mind but I am just saying in case you
didn't think about all these things.

 

[Marine Cpl]

Looked like a .38 revolver and some indeterminate automatic.

.38 Special and .380 hollow points are known to penetrate about 10 inches in gel. Human skin accounts for 4 inches in gel. They didn't penetrate enough and the shot placement was poor.

 

[Podmonkey]

Most rifle rounds at 2200 fps loose most of their capability to produce massive shock.
It is a matter of the terminal design and ballistics. After that most bullets rely solely in
wounding potential alone. This is what pistol rounds do, they compensate for their lower
speeds by introudction section and more aggressive terminal desings like solids and bonded
hollow points.
That is why the 30 caliber was phased out for military use because the rounds are not that
effective at hard barrier and then range is limited to impact above 2100-2200 rounds.
This is the biggest limitation of the 30 carbine and blackout and others.
Small for caliber, low sectional density and slow speeds is not the most desirable so why
then compromise from pistol if one is abandoning those advantages of the 5.56?

.30 was phased out of infantry rifles because the guns were too big, too heavy and not controllable enough in full auto, the ammo was to bulky and heavy also.
Mainly the appeal for me is that the gun is very compact and more effective than a 9mm.
And I already have a good supply of 5.56.
I recently sold all my 7.62x39.

 

[meketrefe]

A simple round that screams in a short carbine is the 357SIG.
Or the 5.7 that was designed to get the most firepower with shorter barrels and w/o the need for a welding helmet to fire
a PDW.

 

[Podmonkey]

.38 Special and .380 hollow points are known to penetrate about 10 inches in gel. Human skin accounts for 4 inches in gel. They didn't penetrate enough and the shot placement was poor.

We don't actually know what the effect on the target was. He could also have been just an especially resilient individual. Which is why I'd like a greater margin than the 9mm gives me.

 

[Marine Cpl]

Regardless, what about the successes of the UZI and the MP5 by Tier 1 operators using ball rounds? Were they all just flukes?

 

[Podmonkey]

A simple round that screams in a short carbine is the 357SIG.
Or the 5.7 that was designed to get the most firepower with shorter barrels and w/o the need for a welding helmet to fire
a PDW.

I looked it up, 5.56 out of this barrel length still out powers a 5.7. But if I had access to a full auto P90 that would be the ideal gun for my purpose.
But I don't.

 

[meketrefe]

.30 was phased out of infantry rifles because the guns were too big, too heavy and not controllable enough in full auto, the ammo was to bulky and heavy also.
Mainly the appeal for me is that the gun is very compact and more effective than a 9mm.
And I already have a good supply of 5.56.
I recently sold all my 7.62x39.

The x39 continues to be a decent round and at least it has the capacity with modern brass to pump a 110gr to 2600fps
but one needs to reload. The 30 carbine and blackout cannot do that.
They were phased out because they are light-for-caliber slow moving cartriges with poor trajectories and penetration in
hard barrier at ranges up to 100 yards.
For example a classic 5.56 will penetrate a considerably thick piece of steel even past 100 yards where the x39 and blackout will fail to penetrate.
same thing with certain types of body armor w/o being the best body armor that might require a more potent cartrige like the 308.

These are pretty realistic requirements in todays tactics.

Something worth considering imo.

 

[Podmonkey]

Regardless, what about the successes of the UZI and the MP5 by Tier 1 operators using ball rounds? Were they all just flukes?

I don't have access to full auto guns. Automatic fire compensates somewhat for lower powered individual shots. But taking your argument I'll turn it round on you. Why has just about every military abandoned 9mm submachine guns in favor of short 5.56 rifles? The UZI was replaced by the Micro Galils after all.

 

[meketrefe]

The round and projectile are important. It is a matter of saying I am going to stay main stream or I am going with something that can separate
itself from the rest in terms of capability.

 

[Marine Cpl]

I don't have access to full auto guns. Automatic fire compensates somewhat for lower powered individual shots. But taking your argument I'll turn it round on you. Why has just about every military abandoned 9mm submachine guns in favor of short 5.56 rifles? The UZI was replaced by the Micro Galils after all.

You think all those shots were full auto? No shot placement whatsoever?

Why was it replaced? Same reason as with anything else. Coolness. For decades it wasn't an issue. .223's were available back then too. The M4 carbine was available since the 80's.

 

[Podmonkey]

You think all those shots were full auto? No shot placement whatsoever?

Why was it replaced? Same reason as with anything else. Coolness. For decades it wasn't an issue. .223's were available back then too. The M4 carbine was available since the 80's.

The 80s is when the transition away from SMGs began. 70s actually. About when the 5.55 bullpups started showing up. Then when people started to realize bullpups kind of sucked militaries started chopping down barrels.

 

[Marine Cpl]

Penetration to vitals are the only thing that matters Pod. Look at all those skinnies in Mogadishu that took round after round of 5.56 mm green tips. The ones that died quickly were the ones that had vitals struck.

But maybe the skinnies didn't read the same energy books that we do to know how to behave when hit with rifle rounds.

 

[Podmonkey]

Penetration to vitals are the only thing that matters Pod. Look at all those skinnies in Mogadishu that took round after round of 5.56 mm green tips. The ones that died quickly were the ones that had vitals struck.

But maybe the skinnies didn't read the same energy books that we do to know how to behave when hit with rifle rounds.

The problem there was that the M855 was just penciling through the thin frames of the Somalies without doing anything. Unless the heart or brain is hit a .22 hole doesn't have much effect. Not in the short term anyway. It's not about penetration, it's not about expansion nor fragmentation. Itss about flipping the switch on the CNS, failing that it's about reducing blood pressure as rapidly as possible, starving the brain of oxygen and incapacitating.
Or as Masad Ayoob points out, a hit that shatters the pelvis is likely to be pretty effective too.
Penetration, expansion, fragmentation, yaw, tumble, big and slow, small and fast. All just means to the end of suffocating the brain.

 

[Marine Cpl]

The problem there was that the M855 was just penciling through the thin frames of the Somalies without doing anything. Unless the heart or brain is hit a .22 hole doesn't have much effect. Not in the short term anyway. It's not about penetration, it's not about expansion nor fragmentation. Itss about flipping the switch on the CNS, failing that it's about reducing blood pressure as rapidly as possible, starving the brain of oxygen and incapacitating.
Or as Masad Ayoob points out, a hit that shatters the pelvis is likely to be pretty effective too.
Penetration, expansion, fragmentation, yaw, tumble, big and slow, small and fast. All just means to the end of suffocating the brain.

And what do you think will happen with a 7.5 inch barrel with reduced velocity? Sure a hollow point can expand a bit but that expansion isn't going to do jack immediately if a vital isn't hit.

The late Dr. Fackler who studied and performed surgery for many rifle wounds for the Army stated that hydrostatic shock had minimal effect even with rifle rounds. He treated many wounds from rifle rounds that were near vitals that didn't produce that lights out effect that everybody nowadays seems to be parroting.

Most of that fragmentation happens in shallow areas even with high velocity. You aren't going to get even that with a 7.5 inch barrel. So you are left with minimal expansion that you still need to hit a vital with. A shot to the gut or the left lung isn't going to knock someone out or have them bleed out immediately. Hell. A shot to an artery doesn't do that.

 

[Podmonkey]

And what do you think will happen with a 7.5 inch barrel with reduced velocity? Sure a hollow point can expand a bit but that expansion isn't going to do jack immediately if a vital isn't hit.

The late Dr. Fackler who studied and performed surgery for many rifle wounds for the Army stated that hydrostatic shock had minimal effect even with rifle rounds. He treated many wounds from rifle rounds that were near vitals that didn't produce that lights out effect that everybody nowadays seems to be parroting.

Most of that fragmentation happens in shallow areas even with high velocity. You aren't going to get even that with a 7.5 inch barrel. So you are left with minimal expansion that you still need to hit a vital with. A shot to the gut or the left lung isn't going to knock someone out or have them bleed out immediately. Hell. A shot to an artery doesn't do that.

I think it will do more than any 9mm. Certainly it's less effective than my 16"AR. Not arguing that. A 10mm PCC would probably be equally effective.

 

[Marine Cpl]

I think it will do more than any 9mm. Certainly it's less effective than my 16"AR. Not arguing that. A 10mm PCC would probably be equally effective.

How do you think it will do more? A .223 expands to about .50 the most if that. Any 9mm can do that. Some even way larger. You might get a sightly bigger hole than the 9mm would do due to the added velocity but a vital struck is a vital struck.

 

[Marine Cpl]

Read this article below. It states that a 64 gr Gold Dot from a 7.5 inch barrel clocks in at 1930 fps. That's below the point where it stretches tissue beyond elasticity. At that point like @meketrefe said, the bullet itself will do the sole wounding. The speed that makes the .223 work as designed is gone. And that speed is only at the muzzle. Now add some distance to it and the velocity gets worse.

A PCC of the same barrel length may even displace more tissue since the expanded projectile is bigger.

5.56x45mm Fired From a 7.5″ Barrel is Just a Glorified .22LR

 

[Airborneguy]

Now this is a great discussion.

I’ve read that human muscle tissue is not dense enough to be fully effected by hydrostatic shock, especially in skinnier people. The key to killing a human is the brain, a vital, or to make them bleed out quickly.

One animal where hydrostatic shock is very effective is pigs/hogs. Their muscle tissue is so dense, a small, fast round like the .223 is fully effective against them, pushing a huge wave of damage through the channel, basically knocking them out, if not killing them immediately.

 

[Podmonkey]

Now this is a great discussion.

I’ve read that human muscle tissue is not dense enough to be fully effected by hydrostatic shock, especially in skinnier people. The key to killing a human is the brain, a vital, or to make them bleed out quickly.

One animal where hydrostatic shock is very effective is pigs/hogs. Their muscle tissue is so dense, a small, fast round like the .223 is fully effective against them, pushing a huge wave of damage through the channel, basically knocking them out, if not killing them immediately.

Hydrostatic shock is indeed a thing. It's just there is a threshold below which the effect is not a source of wounding. Most pistol ammunition sits below this threshold. Most center fire rifle ammo sits above it.

 

[Podmonkey]

Read this article below. It states that a 64 gr Gold Dot from a 7.5 inch barrel clocks in at 1930 fps. That's below the point where it stretches tissue beyond elasticity. At that point like @meketrefe said, the bullet itself will do the sole wounding. The speed that makes the .223 work as designed is gone. And that speed is only at the muzzle. Now add some distance to it and the velocity gets worse.

A PCC of the same barrel length may even displace more tissue since the expanded projectile is bigger.

5.56x45mm Fired From a 7.5″ Barrel is Just a Glorified .22LR

Hmnnn. I'd like to see some gel tests of this.
The. 22lr thing is hogwash though. Even at 1900fpsor so a 64gr 5.56 is far above 22mag, and also the 5.7x28. But does the TSX cover this particular base better? Would it stabilize in a 1:7 twist?

 

[Marine Cpl]

It's been proven that human tissue that stretches beyond the point of elasticity can only happen with projects that travel over 2000 fps. Some tests have shown 2100 fps and others have shown the number to be at 2200 fps. Anything below that and the projectile itself is doing the sole damage like a pistol does.