Military to adopt new round?



Jul 31, 2003
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I found this post while wandering the web...fairly long but has a lot of very good points for those who care about this stuff.

MY PROBLEMS WITH THE M4: Phil Carter e-mailed me, with reference to my last post, inquiring why I don't like the M4 carbine. (He has a certain fondness for it, since he carried one for a while as an MP officer.) I wouldn't go so far as to say that I don't like it in general: in the roles for which it was intended, it's probably far superior to the weapons it's replacing. I just don't like it as a general purpose infantry weapon. I drafted a lengthy post on this topic, but I think it's probably too lengthy. Let me try to summarize.

First, it's highly debatable whether the 5.56x45 mm M885 round that our military employs in the M16A2 and M4 is adequate for military use. Anecdotal evidence from the debacle in Somalia indicates that it doesn't reliably put the enemy out of action unless he's hit several times. Mark Bowden recounted complaints on this point from survivors of the battle in Mogadishu in his book, Blackhawk Down. (This is not to say a torso shot from a single 5.56 round can't kill: it certainly can. The question is when will it kill--fifteen or thirty second from now, or an hour from now? The difference is significant.)

None of this is terribly surprising to many shooters and hunters. The commerical equivalent of 5.56, .223 Remington, is considered a good cartridge for smallish varmints but not, generally, for anything larger. It isn't even legal for hunting deer--which are generally smaller and arguably easier to kill than men--in some states, because it won't reliably give humane kills, except perhaps with very well-placed shots. (In this context, "humane" means "rapid death.") In the military context, rapid incapacitation matters. Every additional moment that an enemy soldier is combat effective is an additional moment during which he can kill or wound friendlies. And although some people may have trouble believing it, some mortally wounded soldiers will continue to fight until they no longer can. That's probably especially true of enemies such as the Taliban and Al Qaeda, or even Somali militiamen, who can't expect any real medical care even if they do stop fighting, and thus have little incentive to leave the fight when wounded. (Their situation is unlike that of our own troops, who can normally expect to receive quality first aid and, if necessary, to be medevac'd within a reasonable time after being wounded. For our troops the choices may be, 1) stay here and keep fighting, or 2) live. For Third World irregulars, the choices are likely to be 1) stay here, keep fighting, and die heroically as a martyr, or 2) stop fighting and die anyway.)

It'd be awfully hard to quantify how many additional casualties we might take because we use a marginal round versus one that incapacitates more rapidly, especially since no small arms round is 100% effective in this regard. But I have no doubt that we have taken (and will continue to take) some additional casualties because of it.

Now, it's always dangerous to give too much credence to anecdotal evidence. Even if the 5.56 works exactly as we'd like it to in 99% of cases, we're probably disproportionately likely to hear about the other 1%. But in this case, the anecdotal evidence only gives credence to a view that long predates events in Somalia, and for that reason I tend to give it a little more weight than otherwise might have.

So let's just stipulate that the 5.56 M885 is a marginal manstopper when fired from an M16A2. The problem can only get worse in the M4. The "book" muzzle velocity for the standard M885 round firing an SS109 bullet from an M4 is around 200 feet per second lower than that of the M16A2. That reduction is due to the decrease in barrel length from 20" to 14.5". (To be blunt, even the 2900 f.p.s. velocity attributed to the M4 seems surprisingly high to me. The barrel is more than 25% shorter than a full-size M16's, but the bullet only loses about 6% of its velocity? That sounds a bit fishy. I'd like to verify it for myself with a chronograph.) If the M885 is marginal when fired from an M16A2, the M885 fired from an M4 is at least slightly less than marginal. It may sound like I'm making much ado about nothing, but I don't think so. You see, if the M885 is even reasonably effective against human beings, it's largely because at high velocities it begins to break apart shortly after impact, causing multiple wound channels, increased bleeding, a somewhat greater chance of hitting a major vein, artery or vital organ, etc. But the minimum velocity at which this will happen is somewhere between 2400 and 2700 feet per second, depending on who you believe. So even fired from an M16A2, the SS109 bullet stops breaking up--and thereby becomes considerably less effective against people--at around 200 meters. In an M4, the envelope is necessarily smaller because the bullet is leaving the barrel at only about 2900 f.p.s. and thus will fall below the minimum velocity that will cause fragmentation at even shorter ranges.

Reports from Afghanistan seem to support the contention the M4 has effectivness problems beyond about 100 meters. Again, anecdotal evidence should always be taken with a grain of salt. Nevertheless, these reports seem to confirm exactly what I'd expect from the M4, so I'm not as quick to discount them as aberrations as I otherwise might be.

So one of my major complaints about the M4 has to do with the effectiveness of its round. But that's largely an issue of ammunition, and fixing the ammunition could fix the problem. (And I'd like to see the ammunition problem fixed, but I doubt it will be.) So what are my other complaints?

First, reduced velocity also makes it harder to hit targets at longish ranges, because it makes the trajectory of the round steeper and thus makes good range estimation even more critical. This probably isn't an enormous problem, because most combat shooting doesn't occur extreme range and the M4's muzzle velocity, while lower than the M16's, isn't a lot lower. But it's an issue, nonetheless: maximum effective range has to be shorter for the M4. (I note that the "book" maximum effective range for the M4 is 600 meters, according to a couple of resources I've found online. To that I say, "hah!" 500 meters is a bit of a stretch for an M16, so I'm not about to believe that a weapon with a muzzle velocity at least 6% lower than the M16, firing the same projectile, is "effective" at an additional 100 meters. Methinks someone either pencil-whipped the numbers or redefined "effective.") And it's not just a matter of accuracy: at 500+ meters, an SS109 bullet--even from an M16--would be quite stable, traveling too slowly to fragment and have lost quite a bit of its kinetic energy. So even if you could hit a target at that range, lethality wouldn't be as good as one would hope. It can only be worse from an M4.

Second, assuming one is using an iron-sighted M4 there's the issue of sight radius: the shorter the distance between the front and rear sights, all other things being equal, the less inherently accurate a weapon will be. Because of its shorter barrel the M4's sight radius is considerably shorter than the A2's. With iron sights this will inevitably translate to reduced accuracy. Admittedly, it doesn't mean it's impossible to hit accurately with an M4; it just means it's harder to hit accurately with an M4.

None of this is to say that there aren't advantages to the M4. It's a pound lighter and 10" shorter than the A2, so it's more pleasant to carry and more maneuverable in CQB/MOUT environments. It's also a big step forward for vehicle crewmen who can't realistically carry A2's in their vehicles, but deserve something better than the M9 if they have to dismount and fight. (Given the choice between M4 and M9 in a firefight, I'd obviously always choose the M4. And since I don't think much of the M9, I'm all in favor of replacing it with the M4 wherever possible!). If the M4 has the SOPMOD's dovetail rail system, it's got a lot of flexibility and some nifty accessories are available. (There's a pretty thorough discussion here.) And at MOUT ranges the reduced velocity of the M4 is probably not a big deal in terms of lethality, as compared to the A2. (But it's still questionable whether the current 5.56 round is lethal enough, particularly at MOUT ranges where killing the enemy right now is doubly important.) Another advantage of the M4, compared to the H&K MP5 series submachine guns that it was at least partly intended to replace, is that the M4 will penetrate soft body armor. Some militaries around the world seem to be taking the idea of ballistic protection more seriously now than they used to, so this is a factor that weighs at least slightly in favor of the M4 compared to pistol caliber submachine guns.

Now, I know the Army and Marine Corps have focused a lot on MOUT in the past 10 years, on the assumption that "the war of the future" will be fought in cities. If one really buys into that assumption, the M4 may make sense as the primary infantry weapon. But personally, I'm not convinced that it's really necessary to fight in cities in most instances, nor am I convinced that all future fighting is really likely occur under those circumstances. So while I think improvements to the A2 may be warranted (the flattop, dovetailed receiver and rail system for the proposed M16A4 sound like a good start), I personally question the wisdom of giving up rifles for carbines. That is why I said I thought the choice of M16A4 over M4 was a good move on the Marine Corps's part.

UPDATE: A couple of points of clarification are in order. First, I don't mean to imply that I don't think 5.56 is capable of being an effective military round, against personnel. But I'm skeptical that a full metal jacket 5.56 can be. Some police SWAT/ERT/choose-your-acronym teams have been using the 5.56 at close quarters for a few years now, and the again-anecdotal evidence has been that it can be very effective. The difference is that most U.S. police departments issue soft point ammunition for 5.56 rifles. Even in the relatively small 5.56, soft points apparently cause a heck of a lot of tissue disruption and bleeding at high velocities, and I suspect they (or, potentially, hollow points or some type of frangible ammunition) would make the M16/M4 more lethal to a greater range. (emphasis my own)

Of course, many would object that using expanding ammunition is against the law of war. Well, in some sense that's true, under the Hague Declaration (IV, 3) of 1899. But the U.S. never signed the Hague Declaration. Thus, the U.S. decision not to use expanding ammo is completely self-imposed, and probably arises mostly from our desire to see ourselves as good guys.(interesting point) But I have little patience with this sort of foolishness. I have trouble seeing how using expanding ammo is somehow less humane than using FMJ ammo that leaves the victim alive to bleed to death or die of a horrible infection, or burning him alive with napalm, or shooting him with a .50 caliber machine gun, or dropping 95 pounds of steel and high explosive on his head in the form of a 155mm artillery round. War is nasty business, and there's no prettying it up as far as I can see, at least with respect to how one actually kills the enemy. (Restraining actions directed at civilians is a genuinely humane thing to do, but that's an entirely different question in my book.) As for the concern that our enemies will retaliate by using the same sort of ammunition themselves, my response would be that most of our enemies probably couldn't care less about the law of war, and would already be using expanding or frangible ammo if 1) they thought it in their interests and 2) it were available to them. (Some rounds for weapons chambered in the Russian 5.45 mm round used in the AK-74 family are already reputed to tumble badly on impact, which causes much more tissue damage than if the bullet were stable. This may well be an intentional design feature. So in some sense it may not be going too far to say that our enemies are already using "enhanced lethality" ammunition, if you will.)

If there's any valid argument against using expanding or frangible ammo in military weapons, it's probably lack of penetration. These things just don't perform very well against most forms of cover. That may be a legitimate argument, but I suspect that only having to hit the enemy once to to put him down might be worth not being able to shoot through certain materials. (And I'm not sure that a steel penetrator like that of the current M885 couldn't be combined with a soft point design, if we really insisted upon penetrating hard targets. For that matter, there was a time when armor piercing and FMJ ammunition were two different things. A return to that system is at least an option.)

Another point I'd make is that I'm not trying to sound like a cheerleader for .30 caliber weapons like the old M-14. Many old-timers see the M-14, per se, as the solution to all problems of lethality. I'm skeptical that that's the case. It's true that the 7.62x51 NATO round retains its velocity better than the 5.56x45, and fires a bigger, heavier bullet, both of which mean that the M-14 will have better range and energy retention (and thus, at least marginally better long-range lethality) than the M16. So if you plan to engage in firefights at extended ranges, yes, the M-14's probably better. But I'm not sure that it's really such a fantastic manstopper, relative to the M16, at least in the 0-300 meter envelope where most shooting will probably occur. It's got more kinetic energy, but a heavy, stable .308 caliber bullet with a sturdily built jacket is likely to bore straight through its target, doing relatively little tissue damage on the way. So it doesn't necessarily put all that kinetic energy to work disrupting tissue. A through-and-through, 0.3" wound channel isn't really all that bigger or more damaging than a through-and-through, 0.22" wound channel, after all. (In fact, because of the 5.56's tendency to fragment at most of these ranges, it may even be a better stopper than the 7.62x51.) I suspect a lot of the 7.62's energy just ends up being wasted. I did some research on this topic a couple of days ago, and discovered that lack of stopping power was apparently a common complaint among soldiers around the turn of the century, when modern, high-velocity, 6mm to 8mm military rifles firing relatively heavy (for caliber) jacketed bullets first became common. (Ironically, some of the chief complainers were British soldiers shooting at--that's right--Afghan tribesmen on India's North West Frontier.) That's consistent with my theory. I've come to believe, at least tentatively, that the reputations as manstoppers of the old M-14, M1 and M1903/M1917 rifles in 7.62x51 and .30-06 have become exaggerated over time. (All that said, though, ultimately, the bigger the bullet, the bigger the hole and thus the tissue disruption, even if the bullet design is pretty awful. A .50 caliber FMJ round is darned near guaranteed to ruin your day. So at some level it's probably true that bigger non-expanding bullets are better than smaller non-expanding bullets.) On the other hand, the German 7.62x51 NATO round supposedly has a much thinner jacket than the American version, and fragments badly upon impact. If that's true, as this paper by Martin Fackler suggests, I'd expect the German round to incapacitate much more rapidly, and kill more reliably, than ours. But again, the question is one of penetration vs. tissue disruption: the harder, more solidly built American bullet will hold together and penetrate hard targets better than the German round. (Again, though, a steel penetrator in an otherwise fragile bullet might be an acceptable compromise, especially since a 7.62 mm bullet is large enough to accommodate both a penetrator of meaningful size and enough lead and copper to allow for significant fragmentation.)

Anyway, I just wanted to clarify that I think a badly designed bullet in nearly any rifle caliber will probably peform poorly against human beings. I'm not wedded to any particular caliber; I just think we ought to make sure that what we use works well, whatever the caliber.