5.56 or 7.62?

[minmax]

Here is a simple enough debate.

Which round is better?

The 5.56m round, which we have tried to convince our allies go to is standard ammunition. What are its advantages and disadvantages in comparison to the old standard which was a 7.62mm round?

I have my own opinion but I will wait to see what y'all think first. I have used both rounds in the past with varying degrees of success and failure.

[ 04-17-2001: Message edited by: minmax ]

[Mike Robel]

You sure like to stir things up. To me, the minimum acceptable caliber to play with is .50 caliber. My prefered weapon is the 120mm FSAPDS-T round, follwed my 120mm HEAT-MP. In the 105mm days, I liked beehive. My PSG told me about the time in Viet Nam, he asked his platoon leader to dush off his tanks, which was being swarmed with VC using those little squirt guns, with beehive and the problem went away.

[Thermopylae]

Heres how I see it

5.56

You can carry alot of it.

Low recoil, high velocity, increases accuracy in snap-fire situations.

High velocity, tumbler effect, gives the light round adequate hitting power.

7.62

Its a heavy round, causes damage.

For purposes of aimed single shots/short bursts its highly reliable.

[Coyote]

You'll notice in TacOps that careful movement and use of smoke allow you to put your infantry nearly on top of your opposition. That makes a high cyclic-rate-of-fire 5.56mm weapon preferable as range isn't really an issue and at close range you must maintain fire superiority or get your bronze star posthumously.

In dismounted ops I'd probably still go with the smaller round to maximize my basic load. You can overcome the shorter range of the 5.56 with training and tactics. You can only overcome running out of ammo by getting more ammo and that is where round-weight becomes a factor. A grunt can only carry just so much.

The weight of the weapon is also important. The last time I carried an M-14 I thought my arms were going to fall off. The only problems I ever had with an M-16 were the front site catching in the brush and a cook-off during a long live-fire exercise.

BTW I (and it looks like all of the other respondents as well) assumed you meant 7.62x54mm NATO. How do you feel about 7.62x39mm Warsaw Pact ammo?

Coyote

Old tankers never die, they rust!

[Stoffel]

When I left the army in 1989 we had the FAL rifle,and the MAG machinegun.

All were 7.62mm.

I liked the FAL although it was relatively heavy compared to the 5,56 mm C6 and C7 the army uses today.

Story goes that the army will buy the belgium light machinegun from FN as well,I believe its called the minimi?

I think that although the 7.62 round is heavier it is more stabile in flight and have more adequate stopping power.

I read that the seals in Somalia were not so happy with these light rounds anyway since they had to shoot a target 6 or 7 times before they hit a vital part in the body.

And what do you think of the programs for a new assaultweapon started in the early 90's?

I saw four prototypes which fired telescoped

flechettes,little darts I thought it was 4.33 mm and without metal cartridges.

There were reports here in the media that the Israelis have used a sort of this ammo against the palestinians in the recent fightings.

[Olle Petersson]

I read an article in some small arms book on the subject of optimum calibre for military weapons.

There had been an exhaustive investigation and comparison between such factors as;

- Weight per round.

- Stopping power. (Knock down effect.)

- Recoil.

Small calibres have low weight and little recoil, but are also low on stopping power (usually causing more of a needle sting instead of a punch).

The result of this investigation was that calibres from 6.0mm and up had enough stopping power, while calibres above 6.5mm were too heavy and bulky to be optimal.

Interestingly enough the Swedish army used 6.5mm as standard rifle ammo until the end of WW2, only to adopt 7.62mm thereafter.

Now 5.56 is standard for assault rifles, but I've heard that the unit that's specialised in urban warfare keeps the 7.62 since it's better for shooting through walls/floors/ceilings.

Cheers

Olle

[Carter]

5.56 mm can be a very effective anti-personnel round.

The orginal idea in developing the 5.56 mm was for the small, but high velocity round to tumble on impact. Tumbling caused large tissue wounds. It may not kill the target, but it will do serious damage. The generals prefer to generate enemy wounded rather than enemy dead, because wounded cost the enemy more.

Developments to the 5.56 mm have created a round that will basically explode on impact, creating a very nasty wound.

Armor piercing variants would pass right through a person, depositing little energy, and most likely doing little damage. I hear the Army's new "green" round also has this problem.

The armor piercing variant of the 5.56 can penetrate at least 6 mm RHA. Non-armor piercing variants might only penetrate 1 mm RHA.

So if you are an infantryman in a short range, full-auto firefight, against a lightly protected enemy, the 5.56 mm is a good bet.

It is light, offers low recoil, high rate of fire, and is generally effective at creating infantry casualites.

The 7.62 mm is more effective at long range, penetrates significantly more armor, and hits harder because it is a larger bullet with more energy.

minmax already wrote some interesting posts a while back about what he did with a 7.62 mm in combat. So I won't even try to talk about it any further.

[minmax]

Very interesting points raised by all of you.

I don't know the research or the experts but I do know that 7.62mm will knock someone down and they stay down. 5.56mm requires a couple or three shots to keep a target down.

I know generals and defense types want grunts to shoot to wound. It is a force multiplier b/c the wounded man will take people off the field.

What I have experienced is it is better to shoot to kill. A wounded person panics and still moves, shoots, and throws grenades.

5.56mm is useless against most armored vehicles.

7.62mm while not optimum it gives you more punch.

As far as weight I have humped an M-14 and M-16. The 14 is heavy but you get used to it. The ammo is heavy either way.

Someone said something about snap shots and full auto. I think I would still rather have a heavier round flying down range.

Well that is my two cents and then some.

[Stephen]

A weight advantage for 5.56 over 7.62 Nato? If it takes twice or three times the hits over 7.62 then a 5.56 round would have to be half the weight of 7.62 or less for there to be an advantage. And I'm pretty sure it is not.

I believe that individual weapons should be effective at normal section ranges, normally considered to be 400m. I personally think 5.56 is a little light for that until about 5 hits.

Section, platoon, company and sniper weapons need to have a greater effective range and I believe 7.62 NATO or bigger are a must. Having said that it makes sense for an infantry section weapon to use the same round as the individual weapons.

How about 7.62 short? Is that a good individual weapon round?

[Carter]

I've read that the 5.56 mm is better than the 7.62 mm short.

Kinetic Energy = .5 x mass x velocity squared

Therefore its usually better to be fast and small rather than big and slow. The 7.62 mm NATO is big and pretty fast.

Another thing to consider is that "Interceptor" body armor that can stop rifle rounds is becoming more available. If the bad guys get good body armor like Interceptor, the 5.56 mm will become less effective.

A 7.62 mm AP would be able to penetrate Interceptor body armor.

[minmax]

I can't answer about the 7.62mm Short I have only used NATO standard 7.62mm.

I agree about the ammo weight issue 10 pounds feels like 100 pounds after 15 klicks and it feels like 1000 pounds on a MCCRES Hump so I don't think it matters if its 5.56 or 7.62. Besides that is why God created FNGs to hump extra gear.

In terms of the physics involved I see what you mean by stating smaller faster packs a bigger punch but you have to accout for mass which means 7.62mm is still an effective round.

I am making these observations based on experiences seeing 5.56mm in M16s vs. 7.62 being used in M-60E3s and M14s and some H&K rifles. I would be interested to here from our Vietnam era brothers observations on the M-14s vs. M-16s which is a raging debate. Much like the old Springfield vs. Garand debate of our Grandfathers.

[Carter]

I did a rough calculation of the energies of several bullets. There are various factors, like barrel length, that could change these estimates.

5.56 mm = 1500 J

7.62 mm Short = 2600 J

7.62 mm NATO = 3400 J

The 7.62 mm Short is supposed to have poor "terminal" effects. The bullet won't break up unless fired at point blank. That's probably why the Russians switched to the 5.45 mm.

On a slightly different note . . .

The US is developing individual and crew served weapons that use 20 mm bursting munitions. These weapons can engage targets while in defilade. The munition explodes over the head of an enemy who might otherwise be behind cover. The weapons are supposed to be substitutes for the 40mm and .50 Cal.

They look like the best new advance in anti-personnel/anti-lightarmor infantry weapons.

[MajorH TacOps Developer]

Weight and bulk matter and they matter all the way from the factory to the rifleman's belt.

Less weight and bulk means more ammo for the rifleman. So long as rifle accuracy and stopping power is adequate at 400 to 500 meters then lighter is better.

If more range and stopping power is needed then the target should be addressed by machine guns, mortars, arty, etc.

I think it was S.L.A. Marshall who said that most firefights at small arms range are lost simply by the side that runs out of ammo first.

[Coyote]

"nullThe 7.62mm offers a psychological weapon that the 5.56 does not -- sound and feel. Anyone who's experienced firing an M60 vs. a SAW will know what I'm talking about."

I don't think the psychological effect is equal on both "ends" of the firefight. Shooting at someone with a bigger weapon might give the user more confidence, granted. The guy on the recieving end doesn't necessarily know the caliber of the incoming rounds. He is mostly impressed by the volume and accuracy of the fire he's taking.

A soldier's concern about what he gets shot with is secondary to avoiding being shot in the first place, hence "supression". Rommel's opinion after WWI was that there should be eight men providing suppressive fire for each one moving forward. "I don't have a copy of "Infantry Attacks" so I can't give an exact quote.

See you at Fiddler's Green

Coyote

[minmax]

Psychological effects are important more so than many are willing to admit.

Some have posted that you seldom know the calibre of the weapon being fired at you. I think that may be true for an FNG but it becomes second nature to vets.

The first time a PKM opened up on us I had no clue what the calibre was but the sound got my attention in a hurry. You see bigger sound equates to bigger/longer range in you head. Now that does not always work out to be rational or true but in a firefight rational is not always a primary concern.

I know that one disadvantage to the bigger/louder weapons is that returning fire focuses on these weapons so you gotta move your bigger weapons more frequently or risk getting triangulated and/or artie dropped on you.

Captain Von Shell's (I think) Book BATTLEFIELD LEADERSHIP talks at length about psychology and the effects of different weapons on troop morale.

I personally like the 7.62mm round over the 5.56mm. Most vets that I served with agreed with the assesment that it knocked down and kept down what you shot at. The crap about shoot to wound only works if your a sniper with the range and hide postition to plink at a foe. Toe to toe firefights are about ferocity, psychology, luck, and good training.

Sorry for the sermon its late in the school day and I am in a foul mood.

[Gyrene]

Hello all, I'm not a poster to this side of BTS's forum nor am I a player of Tac-ops, so forgive me for butting in.

I cannot help to but to agree with Minmax on the point that larger calibers are better in all but very few instances.

A dramatic example can be found in the winter offesives in Korea, 1950.

The CCF forces heavily utilized the Russian PPSh (Known as the "Burp Gun" to GI's and Marines) which fires the 7.62x25 round (Quite a bit smaller then the current 7.62x39 AK round) while the American side favoured the M1 Garand and it's 30.06 round (Which is itself quite more powerful than the 7.62 NATO).

Many American fighting men suffered from multiple hits from PPSh's but a combination of their very bulky clothing and the extreme cold (Which often froze blood on wounds, effectively stopping the bleeding) made the small 7.62x25 caliber much less efficient than the much more powerful M1, which also had the added benifit of far greater range.

Incidently most American forces in the Chosin Reservoir are (And later Korean War campaigns) ditched their M1 Carbines (Firing a .30 caliber round more akin to an elongated pistol cartridge that a 7.62) which lacked the knock down power to stop Chinese rushes and the blowback energy to operate its own action in extreme cold.

How the M16A2 or the M249 SAW would perform the very same dramatic and extreme conditions as in the Chosin is debatable, but I'm sure that the M1 and its heavy cartridge (Along with the BAR) made a great contribution in that campaign.

My unsolicited 2 cents.

Gyrene

[Carter]

I found an interesting web site dealing with the wounds of various bullets.

http://www.vnh.org/EWSurg/ch02/02Projectiles.html

The 5.56 mm, 7.62 mm Short, and 7.62 mm NATO are listed.

The results are interesting.

The 5.56 mm and 7.62 mm NATO both look like they are very effective against personnel, but the 7.62 mm does have better penetration.

The Soviet stuff doesn't seem to measure up.

[minmax]

Extremely interesting web site thanks for the info.

I had a chance over the summer to shoot a fully auto MP-5 very nice!

Well back to class.

Your tax dollars at work teaching the young.

[Stoffel]

Not sure,I had the pleasure of firing the C7 (5.56mm)

last week on a training with a dutch army unit(I was invited)

I used to shoot with the FAL rifle when I was in active service (which is 7.62mm)

Indeed the C7 weighs less than the FAL so does its ammo.

But usual practice is when its not to heavy you can take more,so the weight problem will be the same on a long walk.

But I noticed one thing on the C7 it has less power compared to the FAL.

Whit that I mean you hardly feel a shot go off (pressure on the shoulder)compared to the FAL

After firing that rifle I usually had a blue and painfull shoulder the next day,not the case with the C7 though.

Maybe its the same for stopping power,I dont know.

the stories told in Blackhawk down (if they are true)show a bad result regarding stopping power

[Slapdragon]

One thing that is very important to remember is that the 5.56x45mm M198 round, the 5.56x45mm SS109 round, and the 7.62x51mm round are each completely different in their design, nature, and technology. The 7.62x51mm round is essentially a short 7.62x63mm (.30 M2) that fires a similar bullet design and is based on technology developed in 1894 and modified in 1906. At ranges below 500 meters it overpenetrates targets and does not dump all of its energy into targets. Its bullet shape was optimised for feeding reliability and not wound channel. Of the three rounds it has the lowest penetration and lowest wound channel effect, although it is superior to the 7.62x39mm in penetration. The round out ranges the ability of an infantryman to use it by around 600 meters.

The 5.56x45mm is 1950s / 60s technology. Because the bullet has an unstable cross section, it does not penetrate body armor well, but it has one of the highest wound ratings of a small arms bullet made. When it enters a human, it first causes a supersonic shock wave in the tissue of the target disrupting organs and breaking internal viscera, something very rarely seen in the slower 7.62x51mm. Next, instead of boring right through the target, it will flip end for end because it is not stable, dumping all of its energy in the target. In terms of "killing power" it is the best round here.

The defeat of the M198 by body armor, and the needs of longer range squad automatic weapons led to the development of the SS109, now NATO standard. The SS109 is more stable in flight combined with higher twist rifle barrels, and causes a smaller wound profile than the M198. It is more deadly than the 7.62x51mm, but less deadly than the older M198, instead being more suitable for 700 meter LMG / SAW employment.

the 7.62x39mm performs like a weaker version of the 7.62x51mm, and the 5.45x39mm performs like a weaker version of the M198.

Except in very limited situations though, killing power is subsumed by other factors on the battlefield, so the killing power of a round is not a huge issue as long as you are talking a rifle calibre round.

(So, the earlier example of the 7.62x25mm round is in a different league).

Now -- current research starting as early as the 1930 German studies of small unit warfare has shown that individual weapons fire in and of itself is not a major factor in battlefield combat. The power of a unit is locked in its automatic weapons, and the ability of those weapons to suppress the enemy, forcing them to stop firing and keep there heads down, and to kill the enemy by the use of well targeting automatic weapons fire. In each case, the availability of ammunition to a small unit, and the ability of the small unit to carry ammunition, does indeed carry the day with fire fights. This does not mean random hosing, but giving each man an automatic weapon of a light calibre and a ton of ammo and training them when to exercise various forms of fire discipline is the key to success. The normal model for any force now is to use firepower to hold an opposing force in place for destruction by artillery, or to close for destruction by rapid automatic fire. This is also the methodology of ambush, where "suppression" of an opposing force is the initial goal of a "mad minute" followed by destruction before the enemy can recover.

[Carter]

I think the 7.62 mm NATO is quite deadly.

Look at the figure for the 7.62 mm soft-point (Figure 11).

In the description of the 7.62 mm soft-point it says "although shooting accidents are not infrequent with such rounds, they are rarely seen in the hospital since few victims of torso shots survive."

------------

Additional ballistics information, including more figures can found at: http://www.firearmstactical.com/wound.htm

[Slapdragon]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Carter:

I think the 7.62 mm NATO is quite deadly.

Look at the figure for the 7.62 mm soft-point (Figure 11).

In the description of the 7.62 mm soft-point it says "although shooting accidents are not infrequent with such rounds, they are rarely seen in the hospital since few victims of torso shots survive."

------------

Additional ballistics information, including more figures can found at: http://www.firearmstactical.com/wound.htm<HR></BLOCKQUOTE>

The "few victims shot in the torso" is the key there, not the 7.62. The 7.62 is not an ineffective round, it is just not as deadly as the 5.56 of either variety.

Realize that the film of the shooting of South Carolina Trooper Mark Coates, who was struck under the arm by a .22 LR standard velocity bullet, one of the weakest bullets made, fired from a short pistol and unlikely to have even a hundredth the energy of a 5.56mm at 300 meters, clipped the trooper's aorta. He died in 12 second on tape with little or no external blood loss.

[Stephen]

I'm sorry but what a stupid statement! " The 7.62 is not an ineffective round, it is just not as deadly as the 5.56 of either variety.

"

How can this be! 7.62mm NATO delivers more momentum and more enery to the target. How can it be less effective!

If you are talking about diferent kinds of projectile, then you are talking chalk and cheese! In military use it is normally a FMJ. And all FMJ break up in a similar manner.

Regardless if the projectile tumbles or not, the wound channel for a 7.62 mm is larger than than of a 5.56mm at the same range.

As for imperical evidence people who have used both in combat report that one 7.62 NATO stops where as two or more 5.56mm are needed.

[Slapdragon]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Stephen:

I'm sorry but what a stupid statement! " The 7.62 is not an ineffective round, it is just not as deadly as the 5.56 of either variety.

"

How can this be! 7.62mm NATO delivers more momentum and more enery to the target. How can it be less effective!

If you are talking about diferent kinds of projectile, then you are talking chalk and cheese! In military use it is normally a FMJ. And all FMJ break up in a similar manner.

Regardless if the projectile tumbles or not, the wound channel for a 7.62 mm is larger than than of a 5.56mm at the same range.

As for imperical evidence people who have used both in combat report that one 7.62 NATO stops where as two or more 5.56mm are needed.<HR></BLOCKQUOTE>

The reason is the muzzlel energy is not the end all and be all of effectiveness. Muzzleenergy comes into effect when one considers the effect of the round on bone, and penetration (muzzle energy versus cross section). The 7.62 rounds of all types have three reasons they do not cause as serious of a wound ballistic (per Ezell quoting USDOJ tests on each round).

First, the 7.62x51mm, while not great penetrator against body armor, penetrates skin too well. The energy of the x51 FMJ bullet is not dumped into the surrounding tissues because the more massive bullet maintains momentum better in the fluid of the body. The 7.62x51mm could actually be moving much slower and cause the same amount of damage because it would not over penetrate soft tissue. Overpenetration is wasted energy (it could be solved bu hollowpoints, but for obvious reasons is not).

Next is wouund shock. Supersonic bullets that are still supersonic when they enter the body for the first time trigger a shock wave that can rupture organs. The faster they are going, the bigger the shock wave. Within practical range of an infantry rifle (300 meters or less under combat conditions)the 5.56 has a bigger shock wave because it slows much faster in trasition to the fluid, and because it is going much faster to start with.

Finally is the fact that for both shells, position counts more than shell energy as long as you are talking rifle shells moving over the speed of sound when they impact. A .22 killed Trooper Coats, he shot a man 5 times with a .357 and although hitting center of mass, he failed to strike a vulnerable organ. This although the .357 has the highest rating on the Police deadliness scale (which measure chances of surviving a street shooting by a certian weapon and is based on a census of officer and civilian shootings since 1956 -- something they drill into our heads at the academy).

As for the 7.62x51mm being so deadly no one reaches the hospital alive, it is hogwash. According to Korean War statistics on accidental shootings during training (from US DOD book entitled The Medical Corps in Korea 1950-1953) accidental rifle shootings by US soldiers at a time when (those adjudged not to be malingering or suicide) had a better than 80 % survival rate assuming medical aid was available. In World War Two 75% of all shootings with "rifle caliber bullets" resulted in the casualty surviving. At no time during the last century have rifles ever been that deadly. The issue is location of the shot, not caliber of round, as nearly half of all officers hit by .38 shells in the chest will die if not wearing a vest, and the .38 is not the greatest round in the world.

[Slapdragon]

Let me offer the similie. In stock car racing, why doe the car with the most horse power and torque not always win? Horsepower and torque is the direct equivilant in terms of force to a bullets muzzle energy.

The reason that the 5.56 is actually a better killer than the 7.62 is because the assumption that energy is the only variable. In fact, it is a composite variable with a nonlinear relationship, mostly because the human body is a complex organism.

Here is another example. A large lead pipe swung at a person's chest can come very close to the speed of sound at its tip, and can deliver many multiples of the energy of a 7.62 bullet, but is less deadly. In fact, when we look at police officers on the street, the lead pipe to the chest is far less of a threat than one to the head (changing the body position variable) or a knife to the chest thrust with much less energy.

Then you have the case of body armor. The body armor I wear on the streets will stop a .357 magnum bullet. If that ever happened to me, it might break my ribs and crack my breast bone, but I would be much more likely to survive the encounter. The amount of force I would be exposed to is the same though -- the vest does not "absorb" any energy -- it just spreads it out. Now a 5.56 or 7.62 will penetrate and may kill me, even though so much energy is lost to them by the dispersion of the energy on the vest that the bullet could well be subsonic and thus not have much shock wave, and may even be deflected by the deflector pad in my vest out of the way of the main organs.

This is why the 10mm is relatively rare as a police round and the .40 S and W is fairly common. The 10mm at close pistol ranges may actually overpenetrate its target, and although better at penetrating body armor is harder to shoot. You are better off hitting the chest with a .22 than missing the head with a .458 magnum