How reliable are US small arms?

Thing is, it works: M4 Carbine with accessories used by Big Green. Click to, etc.

Thing is, it works: M4 Carbine with accessories as used by Big Green about 10 years back (the accessories are also under continuous improvement). Click to, etc.

One gets weary of seeing forum commandos and gunshop experts spouting nonsense about current issue weapons. Most usually, this is in the form of bad-mouthing the M4A1, a weapon most of them have never fired, and praising alternatives from the elderly M14 to the HK 416, which is basically a very heavy piston M4 with a nicer finish. Generally, these guys’ knowledge of the M14 and 416 is limited to reading puff pieces in gun magazines, although some of the M14 guys carried them in the early sixties.

We’ve been told that the M4 jams all the time, and that combat soldiers have died trying to clear their jammed M4s as they were overrun, that the M855 and 855A1 ammunition is not lethal at combat ranges, that some M4 features like the forward assist prove its inferiority, and that limited adoption of 7.62mm special purpose weapons like the M14 Enhanced Battle Rifle (EBR), the M110 Semi-Automatic Sniper System (SASS) or the Mk17 Special Operations Combat Rifle – Light (SCAR-L) show that the M4 is obsolete.

Similar vituperation and calumny is directed against the M249 SAW, some of which have been replaced in USMC service but the M27 IAR, an HK 416 variant. The Marines made that decision for tactical reasons, not because of dissatisfaction with the M16 platform (which should be obvious, because the 416 is, after all, 90%+ good old M16).

The M4 (not A1) with standard accessories: Knight's RAS and BUIS. Click to embiggen (wallpaper worthy!)

The M4 (not A1) with standard accessories: Knight’s RAS and BUIS. Click to embiggen (wallpaper size!)

It’s hard to put a finger on why this body of opinion has such lasting power on the internet. It does not square with personal experience of most of these weapons. Some of the stories are not true — the story of dead men with jammed M4s are a recyling of a durable story that actually did occur in Vietnam, but as we’ve previously reported, that happened to a unit that taught their troops that the M16A1 required no maintenance at all. We never experienced an M4 jam (or M16 jam for that matter) that was not due to magazines. Likewise, while basic training and the soldier skill books teach activation of the forward assist as some sort of Santeria appeasement of the Gods of Firepower, we never needed or used the thing, which was added only at the insistence of Army purchasing bureaucrats in the early sixties. They wanted a way to force the bolt closed on an oversize or bulged cartridge, something you could with the op rod on an M14 (or M1 rifle and carbine). This was actually how they killed the US FAL. The forward assist was superfluous then and it’s more superfluous now, with the 60s ammo problems long since worked out.

The units that experienced problems (for example at FOB Wanat) were using M4s as sustained fire weapons in magdump after magdump at near cyclic rate. While it’s understandable why they did that, in that particular circumstance, it’s not a duty cycle within the design envelope of any shoulder-fired infantry weapon and an hour of sustained cyclic-rate firing will cause damage to almost any air-cooled weapon.

As far as jamming is concerned, here’s what the Army says about their reliability requirements versus their results on the M4 series carbines.

The reliability requirement for the M4 is 600 Mean Rounds Between Stoppage (MRBS). The demonstrated current reliability is over 3600 MRBS as a result of our continuous improvement program.

That’s pretty consistent with our experience on flat range, combat range, and in combat operations. That might explain why the Individual Carbine contestants have had such heavy sledding — you not only have to beat those numbers, but you have to beat them by a wide enough margin to justify the costs and logistic stress of a rifle change-over. (Radical rifle change-overs have generally failed in wartime. Britain dropped the superior P14 and went back to the Enfield in WWI, Russia backed off and Germany never went all-in with semi-autos in WWII, Japan and Italy got caught with their logistical pants down in mid calibre-change, the US Army was hesitant on breechloaders and repeaters from 1860-1895 or so).

Now, there are other parts of that 2009 document that are less impressive (the M4’s cumulative testing amounts to 8 million rounds — not a lot when you consider the tests span some 17 years as of that doc’s date), but there are some interesting facts that you might not have known about the M4. For instance, here’s what went into the product improvement program:

To date there have been 62 improvements to the M4, which include improvements to the trigger assembly, extractor spring, recoil buffer, barrel chamber, magazine and bolt.

That’s the stuff that Big Green’s ordnance shop signed off on (there have actually been 30 more improvements since the 2009 letter). There’s more stuff happening at the Naval Surface Warfare Center in Crane, Indiana, for the special operations world, and new ideas are often shaken down over on our side before being thrown over the transom to the big Army. The Army with its hundreds of thousands of troops is less inclined to tinker and experiment.

The M249 likewise is performing well, as far as reliability goes.

The M249 SAW, the Army’s Squad Automatic Weapon, has a reliability requirement of 1200 MRBS and yet today demonstrates a reliability of over 23,400 MRBS.

And it, too, has been product-improved in a number of ways. Bottom line: these are pretty darn good guns.

At the time of the letter, in 2009, the Army planned to run contests for several improved weapons. As it is, these contests are being squeezed between the low budget priority given the land forces and the military in general, and the general satisfaction with  present weapons. That’s what just killed the Indiidual Carbine competition dead as a mackerel.

The Army … plans full and open competitions for an improved modular hand gun, a subcompact personal defense weapon, a new individual carbine and a longer range sniper rifle. The individual carbine competition will address current, emerging and future threats.

The Army has since fielded the M2010 .300 Win Mag sniper rifle, and SOF have other long-range options, so that test came off successfully (after all, the 2010 is basically an M24 with a railed chassis and the heavier chambering, and this expansion possibility is why the 24s were built on a magnum-ready long action from day one). Given the weight and compactness of a lightly-accessorized M4, the PDW is most unlikely to find a niche in the US Army. Pistols take up a lot of mindshare in the gun culture, but in the military they are secondary (if that!) weapons; it will be hard to justify replacing the M9, which is adequate to its de minimus combat task..

The letter was signed by COL Doug Tamilo and approved by BG Peter Fuller. Read The Whole Thing™ and expect a follow-up on more recent M4 improvements.

Note to readers: the Tokarev stuff promised this week is taking longer than expected as we wrangle images.

6 thoughts on “How reliable are US small arms?

  1. Aesop

    “The test of an intelligent man is how much he agrees with you.” – apocryphal.

    WM, you’re a gentleman and a scholar, and there’s damned few of us left.

    Also, I think the explanation is the Cool Kids Phenomenon. If everyone who now claims to have been actually present at Woodstock, for one example, were actually there in the day, the resultant mass would’ve have reached singularity and created a black hole and sucked the planet through a wormhole. Ditto for everyone who claims to have some revelations about the inferiority of the M16/M4 system, back in the day or right now. Everyone wants to be Yoda on this.

    There is a place for the M14 system. It, unlike anything .223-based, turns a lot of things that are cover from .223 into mere concealment. They also deliver rounds at ranges that .223 dares not go, or where it fliess wildly askew due to wind and physics limitations. That’s helpful, particularly when bad guys are shooting from ridges across valleys, and hiding behind mud walls. The old walnut stocked versions were far more suited to things like horizontal butt strokes, which is a lot less helpful, though comforting to some. Because the weapon is heavy, and the ammunition doubly so.

    But for most of what anyone wants a battle rifle to do, the M16 family, as upgraded since adoption, is pretty damn close to the king of the hill, and likely to stay there in perpetuity until beam weapons become a reality. And not least of which is because there are now not just one, but 2,000 product improvement entities whose very economic surivival are tied directly to the continued dominance of that system. We call them aftermarket accessories manufacturers. The concept of making the weapon a Lego-block plug-and-play of cartridge and function conversions hasn’t hurt its continued viability either. Kind of exactly as Eugene Stoner envisioned, albeit less perfectly. Proving once again, that absent a reincarnation of John Moses Browning or the like, no ONE of us will be smarter than ALL of us.

    1. Hognose Post author

      Actually, we find there’s no problem hitting men at 500-600m with an M16-series weapon, even a 14.5″ M4. The problem is the terminal ballistics of M855 at that range is pretty awful. The round was designed for penetration, not for energy transfer, but at that range it doesn’t have a lot of energy to transfer and center of mass hits are frequently not disabling. (And when I say we can hit a man-sized target I don’t mean we can call precise bullet impact on the guy, or make consistent cold-bore first-shot hits at that range like you can with the M24 or 110. I mean you can fire three aimed shots from a supported position and hit the guy). Guys who have done long-range workups find that in Afghanistan, the ACOG’s bullet drop compensator is way off. (The air is less dense than the International Standard Atmosphere at Sea Level that the ACOG is adjusted for). What’s needed is a density-altitude compensating reticle, but in the meantime I worked up some math for the guys to use, for how much they need to lower the hold vis-a-vis the ACOG.

      The funny thing is they learn density-altitude math in jumpmaster school, but that lives in the JM compartment in their head, and they don’t pull it out for shooting!

      ETA: in SF and SOF they still have the SCAR-H. What that’s been co-opted to do is CQB rifle with the 10.3″ barrel, but it was intended to answer that mid-range (between M4 and sniper) use case.

  2. Aesop

    I assumed hit probability for 500m anyways, having regularly accomplished that on square ranges with iron sights on an A2 with little difficulty, as a consequence of marksmanship training that didn’t rely on plastic pop-up targets.
    I haven’t played with the ACOG for more than a few minutes at a time, but the tip about altitude density is useful.
    In any case, shooting at anything other than paper beyond 400m would seem to indicate a choice in rounds that might actually do something besides provide an annoyance.
    My crystal ball is fogged, but just on odds, I suspect future conflicts will be more like Iraq and Mogadischu urban meatgrinders than like A-stan long-range ballistics duels.
    I always thought it was a lot like being asked “Blondes or brunettes?”, where the correct answer is “Both!”
    A squad with a light section and a heavy section would make up for in flexibility what the logistics of a half 7.62/half 5.56 squad would cost in annoyance. We seem to deal well with M240s and 249s well enough, so giving 3 guys around the 240 a 7.62 rifle wouldn’t appear beyond the realm of imagination.

    1. Hognose Post author

      Yeah, the big issue even with 77 grain Mk 262 or what have you is terminal ballistics in the 600m zone. Your pH is higher than it ever was out there (and with the coming weapons of this century — we’ve covered Tracking Point and looked into what Mepro is doing — it’s going to get higher still). But the pK is not keeping pace.

  3. Pingback: How they’re improving the M4 | WeaponsMan

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