Skip to comments.Dueling Rifle Rounds: Itís All About the Wound Channel
Posted on 05/26/2010 11:41:33 PM PDT by ErnstStavroBlofeld
The Times (the British one) has a story about the continuing debate over the 7.62mm round versus the 5.56mm as employed in the long range firefights in Afghanistan. The story asserts that the 5.56mm round used in the M4 rifle lacks sufficient velocity and killing power in long-range firefights. As Defense Tech readers know, weve covered this issue before.
As for the stopping power of the 5.56mm round, that very topic came up at a roundtable discussion I attended with the Armys Program Executive Office Soldier last month at Aberdeen Test Center, Md. It led to an interesting discussion about wound dynamics, the wound channel and the bleed out effect.
Responding to claims that high-velocity 5.56mm rounds pass straight through the body without killing, Brig. Gen. Pete Fuller, the commander of PEO Soldier, said a new 5.56mm round that will be shipped to troops beginning in June, the M855A1 lead free slug, will get rid of what he called yaw dependency.
The current M855 (5.56mm) ball round is yaw dependent. The closer you are to something youre shooting at, the less yaw it has and its going to go right straight through, said Fuller. Also, the M4 carbine has a 14 ½ inch barrel compared to the 20-inch barrel on the standard M16. That shorter barrel cut out 5 ½ inches for that round to get to full muzzle velocity, he said.
(Excerpt) Read more at defensetech.org ...
Why did they ever switch from a .30/06 round to the modern U.N. round?
The NRA ran an article awhile ago claiming South Vietnamese were too small to handle the larger round as a causative factor.
I think I would rather have a Garand - shot for shot than an M-16.
Hint: 7.62 NATO.
Just change the M-4 uppers.
100 rounds of .30 06 weighs about 5.8 pounds. 100 rounds of .223 weighs a little over 2.6 pounds.
Isn’t this countered by stopping effectiveness?
I don’t know. That depends on whether you hit something I guess. I think one of the considerations the military has made is that a wounded man takes two or more men to take care of him. Corpses don’t need any attendants.
OK, I will preface my remarks by saying that I not much of an expert on guns the way so many others are on this site. But from what I learned and what I know from direct experience from tools (where I do have a good background), it seems to me that not every rifle is best for all situations. In some situations the M16/M4 is better and in some situations the larger round 7.62 is better. It all depends on the terrain and the situation. So there will never be the perfect rifle for all situations, just like there isn’t a perfect universal tool.
Sorry, that is Not an Option.
Neither Rounds or Magazines for the 7.62x51 fit in an AR-15 Lower.
So Options would be M14 or FAL or the SCAR.
Ah, the reasonable man. I agree with you 100%.
Like you, I'm not a ballistics expert. And like you, I think there are other things to consider besides pure wound dynamics.
Trying to boil it all down to the downrange performance of a particular cartridge on a shot-for-shot basis begins with the assumption that the bullet hits its mark.
IIRC, somewhere there was research which said that only about 1-in-10 or 1-in-12 small arms rounds fired in combat is actually aimed. The rest are generally flung downrange with a 'to-whom-it-may-concern' note attached, or while trying to ratchet up the flinch factor. The superior performance of elite units depends less upon the innate skill of the soldier, than it does upon the fact that they actually aim more than their regular counterparts.
When you consider the lack of actual aiming, then other factors come into play in selecting a combat round, factors which would include logistics (the bulk transport weight of the rifle and the round) and induced fatigue (carrying ammunition and weapon, and pounding from the recoil).
So the M4 and 5.56 become more likely candidates for issue, when the peripheral factors are considered.
Right on the M1, OK on the M-14 if you need the range. I shot the 1000 yard range with an M1 with iron sights when I could see that far. 20 inch bull but I could at least qualify.
When an enemy is hit and penetrated at long range, he isn't likely to return any more aimed fire. Furthermore, in Afghanistan, he isn't likely to receive much in the way of medical care either.
I give you the socket wrench of the shooting world, the FN SCAR Rifle that is in use by our special forces.
As some of the world’s armies use 7.62 and others use 5.56, and continue to do so, it follows that neither is obviously superior. Each has advantages and disadvantages compared to the other. It’s just a question of what advantages you prefer and which disadvantages you are prepared to live with.
...and wounding has a greater morale effect on the enemy. One of your compadres is killed, that has a bad effect on the rest of the section. One of them is wounded and bleeding and screaming for help/his mother/social security that’s even worse.
“Corpses dont need any attendants.”
And they never come back.
Exactly right, but that won't prevent this longstanding argument from continuing NOR will it prevent the .mil brass from wasting millions of dollars and many lives persuing a one-size-fits-all solution to small arms procurement.
The fully-incomplete list:
A heavy 7.62 x 51 rifle with a 20 round box and 24" barrel will not be a good choice for room-to-room ops.
The 5.56 round may gain you fire superiority in terms of volume, but what the enemy once only used for concealment is now COVER.
The pain in the butt of getting your M16 in and out of rooms and vehicles is payment for the fact that the extra 6" of barrel helped make the round work as advertised.
An M4 is not the appropriate tool to take out the jihadi 1200M away on the next Afghan mountaintop.
You WILL lose muzzle velocity on a 5.56 round when you cut your 20" M16 barrel down to a 14.5" M4 barrel.
When you tighten up the twist on that M4 to get more downrange accuracy on your new, slower 5.56 round, the bullet will now have even more tendancy to punch through and through and not get the yaw and frag that the design once yielded.
When you move to a round designed to defeat Soviet body armor, it may not work as well on unarmored 110lb Somalis.
If you switch from a 5.56 to a 7.62, 6.5, or 6.8, your 200+ round combat loadout WILL weigh more.
If you switch to a "green", lead-free bullet, don't be surprised later on when you find an unpleasant trade-off for your environmentally misguided decision.
Pick your poison. Then bring along a squad designated marksman with a scoped .308. Don't forget the Forward Air controller who's really good with a radio either.
7.62x51 will not fit in a m4 lower, it is to long. AR10 however....
I’ll take the 12 gauge in the hallway for $1,000, Alex.
That'd go a long way towards solving the problem.
If they’re comparing the 7.62x39 round to the 5.56 round straight up, the larger bullet is not “better.” The 7.62 bullet is larger, but it’s much slower. It’s around 2900 feet per second compared to 2100 fps for the AK-47 round.
I prefer the good old 55gr FMJ out of an M4 and a 77gr SMK out of a 20” SPR or M16. That seems to give the best exterior and terminal ballistics for both rifle configurations. Anything else needed is a different tool requirement.
Why use one bullet when three of four will do the same job?
How they got through that article without mentioning bullet weights and twist rates baffles me. Nothing wrong with a “mismatch” of the two, if gnat’s ass accuracy isn’t needed. Give me a bullet that’s unstable enough to flip like a Ukranian gymnast on impact.
“Give me a bullet thats unstable enough to flip like a Ukranian gymnast on impact.”
I am sick and coughing hurts, stop it. lol.
“Why use one bullet when three of four will do the same job?
Don’t know about you but under pressure I’m not such a perfect shot and I don’t know anyone who is. More chances with more ammo is a good thing.
Sorry...was sick last week. Coughing didn’t last long, but it hurt. Get well soon.
If you spray your ammo into the dirt or into the treetops, you will die. Only those who retain fire discipline and "mesh with the team" will survive. A magazine can be emptied really fast on full auto, almost without any meaningful hits.
Belt-fed machine guns are a horse of a different color.
This isn’t about spray-n-pray; this is about real-world shooting, not some mental exercise. No one makes every shot. No one. Not me, not you, no one. Having extra rounds is a good thing. It is a fallacy that it takes multiple rounds of 5.56 to take someone down but only one 7.62.
Frankly, i wonder how many of our soldier’s ballistic problems are actually differences in the ROEs they serve under as opposed to their forebears with heavier rounds.
No one firefights in a vacuum. If our people were allowed to adapt their tactics to the weapons, instead of visa-versa, I think we’d see much better results from the lighter round.
You make an excellent point. How many times are the troops left on their own to fight it out with a rifle when artillery or airs trikes should be used because the ROE doesn’t want to hurt property or isn’t in budget. People talk of 1,000 shots across A’stan’s mountains, but what the Hell for? Those shots are for heavy equipment, not rifles.
That is sometimes true. As a general rule, I'd bet on the 7.62. I'd surely prefer the 7.62 X 51 fired from a nice long rifle if I were in Afghanistan. I like AR-10s and FALs. The M-14 has its problems, but it sure did shoot well. I currently have an M1A with a synthetic stock. It behaves very well. I'd probably depend more on my L1A1 in a real scrape.
You should choose your own weapon. If that is a 5.56 variant, that is cool. I'll willingly carry those heavy 7.62s.
Would you do so in a "duel" where your opponent got to choose the terrain and engagement conditions?
If you are asking if I would choose my weapon appropriate for the terrain and engagement conditions, I would answer "yes".
If you are asking if I would always choose a weapon that used 7.62 X 51 rounds, my answer would be "most of the time".
I think it wise to also have a sidearm and a few grenades. Did I mention deployment with a well-trained and well-drilled team?
I like it when the tanks clear the houses.
I think your rejection of my question, proves my point.
It is manifestly obvious the intent of my hypothetical was to have you choose your weapon BEFORE learning the terrain and engagement conditions.
What rejection, and what is your point?
I phrased TWO answers in order to answer an ambigious question. State your question without ambiguity, or choose whichever on my answers that seems to go with the intended question.
I'll try again, and I'll type really slowly: It is appropriate to choose the weapon according to the situation. I would carry more that one weapon if possible. I prefer the 7.62 X 51, and would probably choose to carry heavier ammo under most circumstances.
That wasn't even slightly obvious. Given this clarity, I would choose a weapon that uses the 7.62 X 51 round.
ARVN wasn't the problem...
“Why did they ever switch from a .30/06 round to the modern U.N. round?”
The 7.62 x 51 NATO cartridge (.308 Winchester) is the updated version of the venerable .30-06 round that takes advantage of the advances in modern gunpowders and bullets to achieve the same/better ballistic performance as the older .30-06 round. 7.62 x 51 cartridge brass can be easily made from older ‘06 brass by renecking to the shorter OAL of the 7.62 round.....well within the capabilities of the average reloader......
It might be noted that the US lobbied/steered Nato to adopting this as the standard NATO round.... the UN had nothing to do with it. A few years after the 7.62 adoption the US reversed course and adopted and pushed NATO to adopt the M-16/5.56 mm (.223 Remington), which to date, is the longest serving Rifle (M-16/M-4) and calibre to be used by the US military.
Highly accurate with good performance down range the 7.62 x 51 Nato round along with the Upgraded M-1 Garand known as the M-14 service rifle would again/still be my personal choice to carry into battle.........
“Hint: 7.62 NATO.
Just change the M-4 uppers”
I believe that it is possible to convert the M-16/M-4 to 6.5 or 6.8mm rounds by changing uppers/barrels, but to get a 7.62 Nato you would have to go to Eugene Stoner’s AR-10 design......
The Nato round is much longer than the M-16/M-4’s magazine/magazine well could accommadate.....
That's one way of looking at it. It's not the way I look at it.
“If theyre comparing the 7.62x39 round to the 5.56 round straight up, the larger bullet is not better. The 7.62 bullet is larger, but its much slower. Its around 2900 feet per second compared to 2100 fps for the AK-47 round.”
Both the Russian 7.62 x 39 and the US 5.56 x 45 rounds are medium power rifle rounds made for lightweight, selective fire, shoulder weapons......
More appropriate is the comparison of these rounds is their respective Muzzle energies
5.56 NATO x 45 = 1325
7.62 Russian x 39 = 1527
7.62 Nato x 51 = 2802
As you can see the %.56 Nato and 7.62 Russian are similiar in Muzzle energy....within 15% of each other......
While the 7.62 Nato round, a high Power rifle round, is hands above at almost double the ME of these two......
You are correct in stating that calibre/velocity is not the whole story.....all 7.62 mm’s are not equal.......
Did we have female combat soldiers back in the Viet Nam Era?
If that is the reason we switched from the M1 type weapon to the M16, it was a poor one.
“Highly accurate with good performance down range the 7.62 x 51 Nato round along with the Upgraded M-1 Garand known as the M-14 service rifle would again/still be my personal choice to carry into battle.........”
Neither the Vietnamese or women was a factor in this.
Stoner developed his rifle and the 5.56mm cartridge was adopted in 1957, well before either of these was an issue.
Other rumors that need to stop:
1. It WAS NOT made “to wound”. It was made to kill and does that just fine.
2. The bullet doesn’t tumble in flight. The bullet design causes the tail-heavy projectile to tumble in tissue, thus causing fragmentation and greater damage.
3. It was never made by Mattel.
And the list goes on.
“2. The bullet doesnt tumble in flight. The bullet design causes the tail-heavy projectile to tumble in tissue, thus causing fragmentation and greater damage.”
In effect, this is worse than a dum-dum bullet which is a violation of the Geneva Convention, no?
The Hague Accords weren’t very technically sophisticated.