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, we’ve 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 Army’s 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 you’re shooting at, the less yaw it has and it’s 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.
save
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.
barbra ann
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 don’t 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.
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