Military History | How To Make War | Wars Around the World Rules of Use How to Behave on an Internet Forum
Weapons of the World Discussion Board
   Return to Topic Page
Subject: The truth about the 5.56mm round
TriggaFingaz    1/24/2004 1:51:19 PM
To all infantrymen and gunusers out there , tell me this: is the 5.56x45mm round an effective round or is it so weak that you need more than one shot to drop a man? Some books say that it is absolutely lethal, able to stop one's heart owing to sheer velocity. Other accounts claim that enemy soldiers hit with this round continue charging. Some books claim it will tumble and dig multiple wound channels in the body, detractors claim it drills straight though people but yet has poor anti-material penetration. Which is more accurate? Please specify whether you used M193 or M855 'green tips'.
 
Quote    Reply

Show Only Poster Name and Title     Newest to Oldest
Pages: PREV  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22   NEXT
Jeff_F_F    Wound effects   3/23/2007 11:45:58 AM
The confusion stems from seeing a bullet hit someone and seeing the wound, and it seems obvious that the effect of the bullet is the wound and the effect of the wound is to incapacitate the person shot. But it is a lot more complicated, becuase there is a lot more going on than just the wound that we can see.
 
Physical effects of a wound: This is the stuff we normally think about. Stretch cavities, wound channels, penetration.
 
Stretch cavity: the size of the temporary stretch cavity caused by a bullet is directly related to the amount of energy transferred by the bullet into the tissue. Deforming bullets are best at this, bullets designed to tumble quickly are better than ones that dont. However this effect appears to be basically meaningless, because soft tissue is very good at absorbing such trauma. The exception here is the brain, because the brain is enclosed by the skull, so penetrations that create large stretch cavities here cause the skull to essentially explode. However direct trauma to the central nervous system generally results in instant incapacitation anyway, so this effect isn't terribly important in combat. Otherwise, stretch cavities are just cool to look at in ballistic gelatin.
 
Wound channel/crush cavity: This is the actual tissue damage done by a round. This is primarily determined by the cross section of the object penetrating the target. Larger bullets, deforming bullets, and tubling bullets create a larger cross section so they create larger wound channels. But the best way to create a large wound channel is unquestionably fragmentation. Wound channel directly impacts lethality because the greater the amount of damaged tissue, the greater the amount of blood loss and the more rapid the onset of shock. However even if the wound channel destroys the heart the brain still has 10-15 seconds worth of oxygen left in it. Physical shock and destruction of the circulatory system cannot instantly incapacitate a person. If the wound channel passes through the brain or spinal cord, that's another matter. See below.
 
Direct central nervous system effects: directly damaging the CNS (brain and spinal cord) is the only way to reliably incapacitate a person instantly. With current technology that means that you have to hit these areas. Note that not even all hits to the head directly effect the CNS, only hits that penetrate the skull above the eyebrows or behind the ears have a chance of doing so, hence the design of modern helmets extending down further in the back.
 
Indirect central nervous system effects/peripheral nervous system effects: There may be effects we don't understand regarding the effects of trauma on the peripheral nervous system or indirect effects of trauma on the central nervous system. Unfortunately it is impossible withour current medical knowledge to distinguish these effects from psychological effects.
 
Psychological effects: The so called "I've been hit" phenomenon. Some people when shot even if the wound isn't lethal just stop and start going into shock. The reason for this is not clearly understood, and ways to make it more likely to happen are not understood either the amount of energy transmitted into the target probably helps here, but the most important variable is the person being shot. Some people go down with minor stuff. Some people take rediculous amounts of damage and keep ticking.
 
If you think "stopping power" can be mathematically predicted from the size of a bullet's stretch cavity or any other measurable variable of a bullet or its performance, I suggest some further reading. These are the citations submitted for the Congressional Medal of Honor.
 
Quote    Reply

Jeff_F_F    Wound effects   3/23/2007 11:55:38 AM

Jesus H. Christ, if you hit a target in the right spot, then it's game over with either 5.56 or 7.62. It doesn't matter which of the two rounds you hit the dude with, he's gonna die if he is hit in a vital organ. Bullet mass, and all of your overly complicated theories/ideas aren't important in the real world. Hit someone in the arm with 7.62 as opposed to the 5.56, he might bleed more, but the result is the same. Hit someone in the heart, lungs, or brain with any of the two rounds, and the result is the same.
 


Sure...but lets carry your arguement to the ridiculous level. Lets issue .22LR to the troops...they can carry thousands!! of rounds then..after all they just need to aim for the head. You want a round that is a compromise between accuracy, penetration, dropping power, and weight. In my opinion the 5.56 fall too short in penetration and dropping power. I've fired thousands of rounds of both 5.56 amd 7.62 in both the military and in civiian life. I handload my own rounds, do benchrest shooting and have been hunting for over 30 years. I wouldn't trust my life to the 5.56 round if I had a choice, let alone that piece of crap M-16. I'd take a M-14 or M-60 over a M-16/M-4 any day of the week.

As far as non vital hits just bleeding more...thats true. But where the advantage lies with the 7.62 round is that at long range the bullet has more momentum so it has more energy that the 5.56 round. We're not talking Ft/Lbs of energy where velocity is the king but momentum where mass is. Which is more likely to push you back..a really fast moving tennis ball hitting your chest...or a slow moving bowling ball??. At long range the 5.56 round has a tendency to lose its energy faster. In addition because of its low mass it will stop and breakk up when hitting heavy bone or cover. Where a heavier bullet will shatter the bone. This is why you don't hunt large or dangerous game with a 5.56...I would stipulate armed men are dangerous game. There is no such thing as overkill...use the most gun you can handle.


5.56 has enough penetration punch through the chest wall into heart or to punch through the skull and into the brain at any normal combat ranges (out to 300m or so). 22LR does not.
 
Quote    Reply

Horsesoldier       3/23/2007 10:36:04 PM

 
Sure...but lets carry your arguement to the ridiculous level. Lets issue .22LR to the troops...they can carry thousands!! of rounds then..after all they just need to aim for the head. You want a round that is a compromise between accuracy, penetration, dropping power, and weight. In my opinion the 5.56 fall too short in penetration and dropping power. I've fired thousands of rounds of both 5.56 amd 7.62 in both the military and in civiian life. I handload my own rounds, do benchrest shooting and have been hunting for over 30 years. I wouldn't trust my life to the 5.56 round if I had a choice, let alone that piece of crap M-16. I'd take a M-14 or M-60 over a M-16/M-4 any day of the week.
 
We've known for half a century that almost all infantry engagements occur inside 300 meters.  An obvious correlary of this is that any round that sacrifices other performance characteristics to get good performance beyond 300 meters is a step in the wrong direction.
Add to that, the fact the in OIF/OEF the findings are that the majority of engagements are not occuring inside 300 meters, they're occurring inside 100 meters.  There is a very real niche role for a designated marksman's rifle in 7.62 (even though the USMC and Army have both found that scoped, somewhat accurized M16s work better than 7.62 guns in this role), 7.62x51 is giving up the things we actually need for an infantry weapon -- things like a large basic load, larger number of rounds in the gun per magazine and lethality optimized for minimal recoil for faster follow up shots and multiple target indexing.  Like I said in a previous post, 7.62x51 never provided an optimum mix of features for what was needed for an infantryman's rifle.
 
It still does not.  7.62x51 can be loaded into much better service rifle kind of combat loads than M80 ball (Hornady's 110 grain V-Max and TAP for instance)  . . . but then you get into the fact that the case length is wasteful for a load that more closely replicates 6.8 Rem SPC, 6.5 Grendel or 7.62x39 M43 performance.
 
At the end of the day (and I say this as a huge fan of the 7.62x51 FAL and 30-06 Garand), all rounds involve trade-offs in performance, and I just don't see the liabilities 7.62x51 brings to the table as being reasonably counter-balanced by the pluses it brings to the table.  It is still not a silver bullet, it still does not provide guarantee of one-shot-stops, etc.  A guy per squad as a DM, plus M240s, is a pretty good allocation of 7.62x51 in a modern force.  More than that is just not justified or overly helpful.
 
As far as non vital hits just bleeding more...thats true. But where the advantage lies with the 7.62 round is that at long range the bullet has more momentum so it has more energy that the 5.56 round. We're not talking Ft/Lbs of energy where velocity is the king but momentum where mass is. Which is more likely to push you back..a really fast moving tennis ball hitting your chest...or a slow moving bowling ball??. At long range the 5.56 round has a tendency to lose its energy faster. In addition because of its low mass it will stop and breakk up when hitting heavy bone or cover. Where a heavier bullet will shatter the bone. This is why you don't hunt large or dangerous game with a 5.56...I would stipulate armed men are dangerous game. There is no such thing as overkill...use the most gun you can handle.
 
A better analogy would be the difference between a fast moving tennis ball and a slow moving soccer ball, if that (5.56mm 62 grain being much closer to half the mass of M80 ball than your analogy or mine reflects).
 
As for hunting large game, that stems from a desire to kill humanely, not an admission that 5.56mm cannot kill deer, etc.
 
Concerning using the most gun you can handle -- again, I'm a fan of the FAL and other full-power rounds -- but for troops who have to carry a real quantity of ammunition (versus a hunter who may go into the woods with a box or less of rounds), it's not just the weight and recoil of the weapon by itself that bears consideration. 
 
 
 
Quote    Reply

PowerPointRanger    Penetration Optional   3/24/2007 1:58:50 AM
The current war presents an interesting scenario:
 
If combat takes place in crowded civilian areas, do you really want a lot of penetration?
 
If you are assaulting a room, you only need ammo capable of going 20 feet, not 300 yards.  A high-velocity, high-penetration round risks punching through the wall and hitting the civilians in the next building.  Under such a scenario, a shotgun would be a better choice of weapon.  (Civilian police run into this same problem).
 Or you might do okay with a low velocity, high rate-of-fire weapon.
 
So would you want a fully automatic .22 short with a 100 round of ammo, or a 5.56mm with a 3 round burst & 30 rounds, or a 7.62 with a sem-automatic & 20 rounds?
 
Quote    Reply

Yimmy       3/24/2007 6:25:53 AM
Remember, at short distance the 5.56mm will suffer explosive fragmenttion in flesh, and so will not over-penerate, as 9mm or 7.62mm would be likely to do.  Hence why American SWAT teams use more M4's than MP5's these days.
 
I suppose it depends on opinions mind.  British CO19 still use semi-automatic MP5's mostly.  British armed response units do also use 5.56mm weapons though, such as Steyr's, H&K33's and G36's.
 
 
Quote    Reply

doggtag       3/24/2007 4:53:19 PM

The current war presents an interesting scenario:
 
If combat takes place in crowded civilian areas, do you really want a lot of penetration?

 If you are assaulting a room, you only need ammo capable of going 20 feet, not 300 yards.  A high-velocity, high-penetration round risks punching through the wall and hitting the civilians in the next building.  Under such a scenario, a shotgun would be a better choice of weapon.  (Civilian police run into this same problem).

 Or you might do okay with a low velocity, high rate-of-fire weapon.

 So would you want a fully automatic .22 short with a 100 round of ammo, or a 5.56mm with a 3 round burst & 30 rounds, or a 7.62 with a sem-automatic & 20 rounds?

From what I understand (read stuff, haven't been there myself), shotgun-weilding US troops are feared in Iraq more than AR-armed infantry.
Would a .410 or 20-gauge auto shotgun satisfy such a query (room clearing and extreme QCB)?
That should satisfy all those too-much-recoil antagonists who cry foul at heavy recoil weapons, as .410 and 20 gauge don't hit you in the shoulder like a 12-gauge (or 10 bore for you British folk), most notably when firing slugs instead of shot.
 
As far as "would .22 weapons work?", (and HorseSoldier, I'm not trying for any confrontations here, nor am I ranting or barking conspiracies), the Russians experienced first-hand in Chechnya that .22 caliber weapons can inflict serious-enough, even fatal, damage.
A current issue of Special Weapons For Military & Police 2007 (Harris Outdoor Magazines, has a Cobb BA50 "Big Boomer" on the cover)
,on pages 23 and 74 (Sniper's Dilemma) talks of Russian experience against these "little" rifles.
   Quote: "The lowly rimfire rifle has repeatedly demonstrated that in capable and determined hands it can be lethal with head and neck shots inside the length of a football field or soccer pitch.  In an urban environment that's plenty of battle space for just about any kind of small arms. To decrease its inherently low signature even more, Chechen snipers crudely fastened a plastic bottle, Irish Republican Army style, to the muzzle of their "Sobol" squirrel guns and cut a hole in its base to allow the lead bullet to exit unimpeded. They were derisively referred to as "fly killers" by "serious" Russian small arms designers, but decibel levels were lowered enough to blend into urban ambient sound, making it much more difficult to acquire a back azimuth.
    The Russians, whether they admitted it or not, were often fatally impressed as face, neck, throat and head shots thinned the ranks of its police and military on duty in places like Grozny. So much were they impressed by this schoolboy's sporting piece turned urban guerilla warfare weapon that they developed their own, but as a more sophisticated professional version. The modular Izhmash SV 99 is a .22 caliber sniper system based on their Biathlon competition rifle..."

More info on these .22 sniper rifles can be found here: http://www.snipersparadise.com/equipment/rifles/SV99.htm
(although the info gets very repetitive.)
 
Now in this area (.22 cliber and shotguns), I do have personal experience, having been a small gamer since 14. A x4 scoped .22 Magnum was my squirrel, rabbit, turkey, crow, groundhog & rats-at-the-local-dump gun for almost a decade until I sold it.
And I can't begin to guess how many .410s, 20-, and 12 gauge shotguns have been thru the family.
If I could, even before military training, hit small game with a bullet (not shot) easily at 100 yards with .22 ammo, making lethal sniper shots by some trained professional isn't really that unrealistic. 
(an interesting note on "plain" .22 rimfire like the 100 & 200 round bricks of Hornet wax-coated-tips I used to buy
 
Quote    Reply

grunt0311       8/2/2007 9:32:12 AM
The M855 round is not a perfect round; no round is perfect. But the M855 does the job pretty well. The problems with it stem mainly from the shooter's bad judgement. The gripes that it won't penetrate certain things like walls or cardoors or anything like that is stupid. If it won't penetrate things like that then don't aim at those things. Don't waste the ammo. It comes down to fire discipline. If you don't have a good target then don't shoot. Now the M855 will shoot through glass without deflecting and car windshields (at least the steel penetrator will make it through) which is where a person should be aiming when shooting a car with a M16/M4. They should be trying to disable the driver not the car at that point. Back to the point, I saw a demonstration with a .45 ACP, a Mathews bow and an ammo can filled with wet sand. The .45 didn't penetrate through and the arrow went through with no problem. The problem is not the caliber or size of the round it is the design of it. If you want more penetration the majority of the mass needs to be in the front. On the flipside if you want more of the kinetic energy transfered to the target the mass needs to be in the middle or rear of the projectile. Now most bullets are designed to have the mass in the middle or rear of the projectile because they have sufficient velocity to ensure that their inertia carries them deep into a target. This also helps to deform the bullet and helps with the fragmentation because the rear mass continues to push from the back while the target pushes from the front. So there are two forces working to deform the bullet. While arrows on the other hand derive their inertia from the mass of the arrow so to ensure good penetration they have increased mass at the front of the projectile because the mass of the fieldhead or broadhead continues to pull the arrow deeper. Now the steel penetrator changes everything because it it strong enough to resist the forces deforming the bullet because it is designed to penetrate hard targets, not soft targets like flesh. Depending on where the round strikes its target (in this case a human) there are other factors to determine the lethality of a round. Does it strike bone or soft tissue? Is the target wearing body armor etc? I had a corpsman explain it best by saying, "skinny people will handle a gunshot wound better than someone who is bigger, more muscular, because they have nothing to slow down the round." The round is able to pass right through them without losing a lot of inertia. Ideally a combat projectile should be able to penetrate armor as well as being able to fragment in a soft target for increased lethality. Until a round is designed that can do those two things it really isn't going to matter what caliber it is. I have seen Iraqis shot multiple times with 7.62 and 5.56 and still be able to fight. It really doesn't matter what caliber is used if you don't hit the target in a vital area. I personally would rather have a weapon that allows quick accurate following shots over a one shot wonder because that one shot is not always one shot. So the argument shouldn't be over what is the right caliber. It should be about making the bullets more lethal because shot placement will always be more important than shot size.
 
Quote    Reply

Nichevo       8/2/2007 4:32:37 PM
I agree that bullet design is key.  And of course we are limited by the Hague Convention (not Geneva IIRC).  So what can be done within this framework?

No expanding jacketed bullets.  Okay.

1)  Solid lead bullets, perhaps lead gas check, perhaps not?  SWC bullets would be murder at close range, really add something to pistol or SMG.

2)  Solid jacketed hollowpoints?  No, I mean to include jacketing the tip.  However, the tip is hollow - concave.  The bullet will therefore not expand, but should create a greater wound through shock and energy transfer.  It could have a ballistic nosecap if desired.

3)  For CQB/nonlethal apps:  assuming you want chiefly to STOP the foe, a very large blunt slug at low speed with low SD.

This reminds me - gf, you mentioned involvement with MetalStorm?  Could we correspond?  I have a thought for you there.

 
Quote    Reply

historynut       8/3/2007 12:34:01 PM
I notice that the people that complain the most are the one's that use it the most and are able to compare rounds. So when they say that a round bigger then 5.56 but smaller then 7.62 would be nice I tend to listen. No one is saying the 5.56 round is no good, just that a little bigger round could be a lot better. So why not test it and find out.
Worst case you spend a few million dollars testing it. Best case you get a round that saves a few lives.
 
Quote    Reply

flamingknives       8/3/2007 2:12:57 PM
My experience was that it is generally the people with least experience who complained about bullet size.

The parameters and variables involved in lethality of various rounds are so diverse that a comprehensive test programme would be financially and morally impossible. The only way to determine lethality is to shoot lots of living people in order to develop a validated model.

Nichevo:
Indeed it is the Hague convention, not the Geneva Convention that imposes limits on bullets. There is a specific ban on explosive bullets, but the wording of another part is prohibiting along the lines of "Weapons that cause unnecessary suffering" so the wadcutters or concave-tip bullets would likely fall foul of this legislation.
 
Quote    Reply
PREV  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22   NEXT



 Latest
 News
 
 Most
 Read
 
 Most
 Commented
 Hot
 Topics