The SAWs that never WAS, part 5: from Minimi to XM249

The US Army hadn’t ever adopted a gun from Belgium until the M249 SAW (which is now made in the USA, but was always a Belgian design). The US has a reputation for not accepting foreign weapons, but historically that’s not entirely true. The first muskets owed a great deal of design featured to the French Charlevilles that armed so many Continentals. The Minié ball that made the rifle musket of the Civil War so lethal was invented… in Belgium. We bought the Krag from Norway, and the Springfield 03 was a license-built development of the German Mauser.

M249 as originally issued, in use in the Gulf War. DOD Photo,

M249 as originally issued, in use in the Gulf War. DOD Photo,

In the 20th Century, Belgian guns came close several times before they grasped the brass ring of an American contract. The FN FAL was a finalist, test weapons being produced in the States (by Harrington and Richardson) as the experimental T48. The FN MAG was briefly considered, but rejected in favor of the inferior M60. It was almost as if there was a Belginx. But any jinx was broken when the FN Minimi edged out all contestants for the US SAW contract. (In time, the MAG would win several rematches with the M60, and become a US standard weapon decades after its initial rejection).

A Light Machine Gun is Born

This FN Minimi prototype shows some M249 improvements feedingf back to FN, like the softpack  and handguard. Date unknown.

This FN Minimi prototype shows some M249 improvements feeding back to FN, like the softpack and handguard. Date unknown.

Belgians, and Walloons in particular, pride themselves on certain areas of national prowess which include beer-drinking and gun manufacturer. FN was, of course, John Browning’s European partner for many years, and it produced many proficient designers and engineers of its own.

While the US SAW program was still taking baby steps, across the Atlantic the Minimi began with a clean sheet of paper, and dissatisfaction with the portability of existing MGs, including FN’s own MAG. Some time around 1970, a team led by Ernest Vervier sat at a chalkboard at Fabrique Nationale in Herstal, Belgium, and began to design a new light machine gun. Their goal was a much lighter and more portable gun than their MAG (Mitrailleuse à gaz, gas-operated MG) general purpose machine gun. They also wanted to use the weapon to increase the range and punch of the rifle squad, much as the BAR had done, but the MAG was too heavy and bulky to do. Their first design was for a 7.62 x 51mm gun, but this gun does not appear to have been constructed at this time. Parallel developments at FN in the ammunition field made it possible to increase the range and penetration of a 5.56 round, so the Minimi team used the new FN SS109 round. This was the standard 5.56 x 45mm cartridge, but with a heavier bullet (63-grains vs 55) that required a faster rifling twist (1:7 vs 1:12) to stabilize it. The 5.56 Minimi was then able to be built some 3-4 lb. lighter than a 7.62 version would have been; the Minimi as tested in 1974 weighed about 16 pounds, and the 1977 version just over 15.

When the US issued the “Material Need” specification for the first round of SAW candidates in March, 1972, FN was not ready to participate, and the 8 Mar 72 spec required a 6.0 x 45mm gun, something FN would only do, if at all, after debugging the 5.56 gun, which looked more commercially viable. (This was a prescient call on FN’s part). The FN gun was ready in late 1974. It looked more like a baby MAG than today’s M249, with a slender steel-channel receiver containing welded-in rails the bolt carrier rides on, a wooden buttstock, plastic pistol grip, and no handguard except for a ventilated forward-receiver section (which still exists under today’s handguard) and the ventilated legs of the sheet-steel bipod. The rear sight was mounted forward of the feed tray hinge, and the front sight well forward on the barrel, right behind a muzzle brake with three holes on each side. This is the initial 1974 version of the gun. The image is from Small Arms of the World by Smith and Ezell, 11th Edition, page 67:

FN Minimi 1974 Army test

The interchangeable barrel came off with the adjustable front sight and gas system; the gas system had a regulator scaled down from the effective one on the MAG. It had two positions, normal and “adverse,” in order to keep a gun rocking when it began to foul. (The troops would soon discover that you could increase rate of fire — and wear — by putting the gun on “adverse” while it was clean). The bolt and bolt carrier were unmistakably inspired by the AK bolt system, inverted; the resemblance of the Minimi’s three-lug bolt and fixed-piston carrier to the Kalashnikov design is very close. The right-hand charging handle did not reciprocate with the bolt. The original Minimi spawned many variants and successors; all that are known to us fire full-automatic only from an open bolt. One of the earliest improvements, shown here, meant to address two Army requests: this post-1974 gun still has no alternate feed and a fixed (apparently wooden) stock, but it has a handguard reminiscent of the FN FALO, a ring for attaching the gun to a tripod pintle, a lightened bipod, and relocated sights (although not the final versions of any of these). This image is from Small Arms of the World, 12th Edition, p. 101:

FN Minimi 1974 Army improved

FN Gets Invited to America’s SAW Dance

With the Minimi getting a great deal of publicity and mindshare, General DePuy  of the Army’s Training and Doctrine command ordered that it, and its funky new ammunition, included in the initial round of developmental and operational tests which began in December, 1974.  The commercially-developed Minimi and HK23 were used as commercial yardsticks for the three Army designs (XM233/4/5). A modified M16 with a snail-drum magazine was a military-developed yardstick: it was preferred, at the outset, by the Marines. This is the 1977 version of the Minimi as tested by the US Army (image source, Small Arms of the World, 12th Edition, p. 101). It shows the alternate-feed and lightened stock, handguard and bipod, and the rear sight is close to the final version:

FN Minimi 1977 Army XM249

The HK23 fell by the wayside in a disputed series of calls over reliability and safety, and one Army-developed gun was clearly stronger than the others, the XM235. The initial modified M16 also couldn’t keep up with the belt-fed guns. But the surprise of the whole event was the reliability of the brand new, untested Minimi. It performed as well on that measure as the XM235, enough to earn it the respect of the testers — and the Army brass watching the competition closely. This early Minimi did not have the alternate-feed arrangement for firing from FNC (M16), and later STANAG, magazines.

Soldiers and gun-culture civilians also followed the competition with interest, and a bit of sympathy for FN as an underdog: the company had lost the last round of rifle and machine gun competitions to inferior weapons, the M14 and the M60. (Proof that the FN weapons were better than the US ones came in overseas sales: the M60 garnered few, and the M14 only one (Taiwan). FALs and MAGs were sold to scores of countries).

Even as the Army boiled its interest in contenders down to the XM235 alone, ditching the modified M16, the H&K HK23, and the XM233 and XM234 prototypes, Army officials, both ordnance officers and senior officers, had been watching the Minimi with great interest. General DePuy wanted to see the Minimi compete in a shoot-off against a developed version of the XM235, the XM248, which took the basic 235 design and incorporated an Army ergonomics checklist (and conversion to a new 5.56 mm cartridge that was competing with the SS109 in NATO tests). The Army officials had separated the ammo testing from the SAW testing; whatever SAW was approved would be made to work with whatever ammunition choice the separate NATO committee reached.

FN Modifies the Minimi for America

FN, meanwhile, was intensively developing and testing the Minimi and its SS109 ammunition. Soon after the gun was shown to the public for the first time, they had a dual-feed system that would interchangeably use belts and FNC, later M16, magazines. The dual-feed, or as FN called it, alternate-feed system, was developed by a team led by FN’s Maurice Bourlet, and patented (it is US Patent 4,112,817, filed in April 1977 and granted in september 1978). The ingenious feed mechanism blocked the magwell when the belt was in place, and blocked the beltway when the mag was in place; it was on the gun all the time and required no modifications, unlike the interchangeable parts of the H&K, or the feedway adapter that Curtis Johnson developed for the XM248, that allowed M16 magazine use by swapping parts.

In addition, FN heard Army complaints about the lack of handguards (and burnt fingers on exposed barrels) and began developing several versions, as well as improved bipods, fixed, folding and retractible tubular stocks and a plastic version of the wooden original. FN photos from the 1970 show many variations of sights and bipod as well; the sights migrated back onto the feed tray cover (rear) and the gas block respectively, keeping about the same sight radius as the original design.

More fundamentally, the Minimi receiver underwent several changes. The final 1979 XM249 version had a receiver made from a single stamped and folded piece of steel sheet, with sheet steel rails spot-welded in place. (This is also reminiscent of contemporary Kalashnikov practice). The barrel-change mechanism was simplified and lightened. The 1974 Minimi had been over the Army’s desired weight of 21 lb., as stated in an October 1976 revised Material Need Statement; the changes to the receiver, stock, sights, barrel and bipod were instrumental in making the number by 1977. Here’s another XM249 prototype.

FN_Minimi_prototype

As we’ve recounted previously, the final four in 1979 were the Army-favored XM248, the Minimi as XM249, the H&K (lobbied back in) as XM262, and an M16 derivative, designed by an Army lab but included at the insistence of the Marine Corps, the XM106 Auto Rifle. (The Marines ultimately accepted the SAW, but they really did not want a belt-fed gun, because they wanted to keep their squad auto gunner’s load down. Many years later they would replace their squad-level SAWs with HK416s — an M16 derivative).

The zero-effort conversion from mag-loaded to belt-loaded feature was FN’s response to two other guns’ — H&K’s XM262 and the Ford Aerospace XM248 — ability to convert from belt to mag fed at the pull of a push-pin and the swap of a module. FN did them one better by building the mag module in to the left side of the receiver below the (belt) feed tray. This cunning solution exacted a very small weight penalty and allowed the feed change without carrying spare parts or partially disassembling the gun. While it had some problems feeding from the magazine, these were ascribed to normal teething in a set of hand-tooled prototypes, and in engineering terms, the FN solution was far more elegant than Ford’s or H&K’s. H&K, though, also offered a slam-dunk-easy caliber conversion, which was one of the XM262’s great strengths. Neither of these features had been requested by the Army, but of the two, they considered FN’s mag feed to be the more interesting one.

The Army was picky about the furniture and trim on the XM249, and the guns went through several iterations of handguard, sights, stock and bipod. The final handguard was a plastic one with a thick schnabel-like collar on the nose end to prevent the gunner’s hand slipping forward onto the hot gas tube or barrel. The final stock was made of metal tubes; the sight was adjustable by two knobs; the safety was a cross-bolt push-button, as in many sporting arms, and a plastic handguard pinned onto the receiver. The Army also disagreed with FN’s practice of satin-chroming the interior of the weapon, and guns made for the US forces would never have this feature. (The Army had found in the 1960s that chrome plating sometimes hid metallurgical flaws in M16 bolt carriers). Ammunition came in a hard-sided plastic (polystyrene) box that held a 200-round belt. This illustration of the original gun graced the original (1985) manual for the M249:

M249 illustration US Army

The M249 would become a well-loved gun, although some soldiers have always had some other preference, and it would have its share of problems. But the question is: how did it beat the preferred XM248 and the very good HK21A1 in 5.56 in the competition in the first place? There have been many conspiracy theories advanced but the answer seems a little bit simpler: the FN entry was a better gun, at least for the criteria the Army was seeking.

The XM249 in the 1979 competition

As previous installments in this series have made clear, the gun to beat going into the 1979 competition was the XM248. Army ordnance officers loved its forerunners’, the XM235’s, clever design, near-perfect ergonomics, and smooth, low-recoil firing experience, which let it put lots of rounds on target. In addition, they were impressed as well with its high reliability and the maintenance and logistical benefits of its modular design. The other gun that had caught the brass’s eye was the Minimi, as in those years FN was conducting demonstration after demonstration — worldwide — of its portability and firepower. (They even brought it to Range 44 at Bragg and demoed it to every SF light weapons class, long before it was type-classified, hoping to build a groundswell of preference among the sergeants’ mafia). The H&K XM262 and the Army-built, but USMC-preferred XM106 Auto Rifle were only in the competition as sops to influential opinion — in the HK’s case, to keep Congress off the Army’s neck, and in the XM106s, to pay lip service to the Marines.

But the test brought out a few surprises. In the various mods that Ford Aerospace had dutifully applied, under Army direction, to the XM235 design from Rodman Labs, they had somehow killed the best of the gun’s advantages. The move of the pistol grip to make it easier to shoot from either shoulder negated its near-center-of-gravity control. And the reliability, the XM235’s singular strength in its 6.0 x 45 mm version, was poor.

The standout was the XM249, with the H&K XM262 a close second. (H&K and FN had taken no chances with the test, and each had provided 18 very-well-inspected and -tested guns). Had there been a huge differential in the cost or contract terms, the Army might have selected the HK21A1, but they didn’t; in May 1980 they announced to the world that the XM249 had won and would be standardized as the XM249.

The M249 and its Progeny in US Military Service

It took some years for the thousands of M249s to be procured. The first 2,000 of them were made in Belgium, while FN was setting up US production. Subsequent M29s have been made in the United States.

The original M249 with the adopted version of stock, bipod and handguard, but with what looks like an oddball rear sight, and the FN-designed flash suppressor. This flash suppressor would later be replaced by the standard M16A2 version.

FN_Minimi_m249saw

Early in its career, the M249 received a product improvement package (PIP). The tubular stock was replaced by a plastic one quite close to the shape of the 1974 wooden stock, but containing a hydraulic buffer. The handguard was replaced by one with an upper heat shield (a quotation from “The Gods of the Copybook Headings” seems apposite here). The sights were modified, the flash suppressor replaced with the standard A2 part, and a grooved pistol grip replaced the original smooth one.

M249 PIP

fn_minimi_m249_PIP

Here’s another picture of the PIP version.

m249-PIP

When the wars in Afghanistan and Iraq broke out, the standard version of the 249 was the PIP, in most combat units with an added Picatinny rail on the receiver, often mounting the Elcan M145 machine gun optic. These have in turn been replaced by ACOGs. Further modifications include more rails and a collapsible/adjustable buttstock. In addition, with all the guns old and well-worn, the receiver rails have been prone to breakage at the weld. The spot welds have been replaced by continuous welds when guns are rebuilt. Also, the two-position gas selectors have been modified to only have the “Standard” aperture (Joe was leaving it on “Adverse” all the time, wearing the guns out).

The biggest disappointment in the field has been one of the features that wowed the Army back in the 1970s — the alternate feed. M249s are just not reliable feeding from magazines (the most repeated theory is that the cyclic rate of the gun is too high for the mag to feed. But the same mags feed OK in an M16A1 with a much higher cyclic rate, so the theory’s probably high-sounding bunk).

Special Operations Forces use two more versions of the Minimi that are not technically M249s, but certainly share its DNA. The Mk 46 is a 5.56mm gun that is shortened and lightened; it has an adjustable stock resembling an M4 or CAR-15 stock, and a Knight’s Armament rails system. It dispenses with the problematic alternate feed and is a belt-only gun, and is available with a shorter barrel. Here it is:

PEO_M249_Para_ACOG

The Mk 48 is a 7.62mm version… bringing the Minimi full circle to its 7.62mm roots.

Mk_48_PEO_Soldier

The USMC began replacing its M249s in 2011 with the M27 Infantry Automatic Rifle — essentially, the magazine-fed M16 variant they wanted in 1974. Persistent, aren’t they? The Marines did not care for the weight of the gun in the squad automatic role, and considered it wasteful of ammunition.

The Future of the M249

The Army expects to replace the M249, but for different reasons than those already cited by the Marine Corps. The Army’s M249s are at the end of their useful lives; almost all of them are over 20 years old, and many have been hard used in training and combat during that period. So Big Green is in the early stages of what could be the Next-Gen SAW. Given that the original project began in the 1960s, ran tests in the 1970s, and fielded guns in the 1980s, today’s buzzcut private could well be retired from the Army by the time the new gun shows up in unit arms rooms.

Until then, the state of the art SAW is the M249.

12 thoughts on “The SAWs that never WAS, part 5: from Minimi to XM249

    1. Hognose Post author

      That’s true. It was many years before the gun escaped tanks, but it was the initial coax for the M1 Abrams and the Bradley fighting vehicles. When it was up for competition in the tank, its competitor was a very strange M60 variant with little commonality with the infantry 60. It did have all the reliability and durability issues. What kills 60s is if they are not heat-treated just so during manufacture, the receivers stretch. And even if they are, given enough time and enough rounds, the receivers stretch. OTOH the Stellite-lined barrels they pioneered (in light guns, anyway) are the heat. FN offers stellite as an option to its worldwide MAG and Minimi customers — it almost doubles barrel life, especially if your joes are prone to fire long bursts.

      I should probably do one on the procurement of the M240 because the tankers raving about it were instrumental in getting the grunts to give it a second look.

      1. Aesop

        Baby Brother, the former TC, raved about the FN MAG.
        Detached for a brief and hated sojourn with the Cav scouts (like all true treadheads he loathed walking, esp. with an annoying amount of field gear), his recollections of having to dummy-paracord all the main groups of his M-60 because things like buttstocks and trigger groups would fall off the damned things while being trundled over hill and dale 24/7 would give a platoon sergeant (and unit armorers) grey hairs faster than privates on a weekend pass. That, and the clever design enabling key moving parts to be successfully misinserted bassackwards should have been reason enough that in any conflict, we airdrop bundles of M-60s on the enemy, in hopes they’d pick them up and try to use them.

  1. Daniel E. Watters

    One explanation I’ve come across for the poor performance with magazines is that the original XM249 test samples used machined magazine wells welded into place instead of the stamped units used on the production model. I’ve only seen this alleged in an article from mid-1980s after the early complaints resulted in Congress pulling procurement funding.

    1. Hognose Post author

      That’s plausible. Most of what I recall reading at the time (in things like JDW, Armies&Weapons, International Defense Review) was GIs bitching about it and the ordnance shop telling them it was all in their heads!

      I can’t tell from the rotten pictures I’ve got how that mechanism was made, and the patent (US 4,112,817) is silent about the manufacture of said, “sleeve which can serve the purpose od guide for a magazine,” which is typical of patents. They don’t normally talk about manufacturing tech unless that’s intrinsic to the invention, and there are dozens of ways to slice any one mechanism, manufacturing-wise.

      http://www.google.com/patents?id=zo06AAAAEBAJ

  2. Aesop

    And on the seventh day, FN rested, and said, “It is good.”

    Here I break ranks with the current-issue Misguided Children: the SAW is still the way to go.
    “Wasteful of ammunition” was the same absurd claim made when we switched from muskets to breechloaders, from Trapdoor Springfields to 1903s, for 1903s to Garands, from Garands to M14s, from M14s to M16s, ad infinitum (a longrunning Leatherneck comic strip called “Qvantico Corps” about the mythical Roman-era Marines probably had a centurion complaining that bundles of arrows wasted more ammo than issuing a single javelin per man).
    A LMG hosing lots of bullets at the enemy is a feature, not a bug, especialy if they’re all running towards your guys with malicious intent. If the rounds are wasted, that’s a training failure, not an engineering and design flaw.

    I’d like America to design the best weapons in the world, but when surpassed, I’ll settle for our military buying our guys the best weapons in the world. SAWs and FN-MAGs are just fine for that party.

    1. Hognose Post author

      You missed the Krag! And the reason the unlovely and unloved Krag was chosen over, inter alia, Peter Paul Mauser’s brainchild, is that the Krag had the very best magazine cut off to stop those damned soldiers from wasting ammunition on the enemy. (Which when you put it that way….)

      1. Aesop

        Artistic license.
        If it hadn’t been for Teddy Roosevelt and a hiccup of a few months’ action in Cuba, the Krag would have been the B-58 of infantry weapons: pretty, lots of great ideas, and never heard from again. Someday I’ll have to track one down for the rack just because.
        There are probably a few thousand of them in cosmoline in Albany and Barstow MCLB, because they never throw anything away.

        And we note that the 1903 had the same Mauser mag disconnect to keep troops from wasting…yeah, that.
        And that my M-16A2 had a three-round burst instead of rock & roll because…
        And that the SAW was originally intended to use 30-rd. mags so that…
        One wonders why they don’t just go back to the BAR, maybe reworked for 7.62×51 with a helpful 5- or 10-round magazine, to keep from…

        Actually, this does more to answer the previous question about why the bayonet hangs on. With all those military geniuses always finding new reasons not to let troops shoot up the enemy, having the front end pointy is probably just a gesture to keep the rifles from being swung like clubs, which bends them up a bit.

        One cannot help but recall Longshanks’ comment in Braveheart: “Arrows cost money; the dead cost nothing.”

        1. Hognose Post author

          1. The magazine adapter on the SAW was there as a backup to the belt, that’s all.
          2. The FN-MAG is the BAR, with the bolt inverted so it can be belt fed, and manufacture simplified.
          3. Longshanks was the bad guy.

          Yours in film appreciation,
          – Nose

  3. Bill K

    My son is a 249 gunner in the Marines, not that far out from MCT – hit the fleet in July. But he says that the 249 jams fairly frequently, and I don’t know why – his calls home are pretty brief. I’m reasonably sure that he takes care in cleaning. He did before he joined the Marines. Any thoughts?

    1. Hognose Post author

      The Marines have owned his 249 since sometime in 1986 or so. It’s a good design, Bill, but anything where metal rubs on metal is going to wear. At some point you can’t rebuild ’em any more… even airplanes, the most rebuildable things going, sometimes they tell you your engine core has been rebuilt as many times as possible, and can’t be brought back into spec. I wonder when it was last TI’d. The Army is supposed to do this before every deployment, and I would guess the Marines plan to have it done before every cruise or deployment, too. In a Technical Inspection, specialist inspectors with tools and gages examine a unit’s weapons and sign them off as in spec, or downcheck them for rebuild. (Of course if his MEU or whatever turned in worn 1986-vintage M249s, they might get worn 1986-vintage M249s back. Hopefully ones coming from storage that have passed TI. But intermittent problems, and most jams are intermittent in any gun in the field, are very hard to diagnose).

      Most sport shooters have never seen a worn out gun, and the US military usually does replace them before they’re that bad. But it’s really hard to squawk a gun that has intermittent problems. The chain of command has to make it an issue.

      1. Bill K

        Thanks! He does like the M2, and seems to think of that weapon as ‘Mr. Reliable’. Maybe of more recent vintage, from what you say. At any rate, he’s supposed to be on leave for Christmas, and I hope to get the skinny then. He also said, even before the sequester, that the Marines have a yearly ammo allotment, that is smaller this year than last, from what his older companions tell him. They’ve mostly burnt through it. He’s bummed that they don’t get to practice more – I think he said that he’d fired the 249 only 3 times in the last couple months (don’t hold me to that). How are guys supposed to get proficient if there’s no money in the budget for enough ammo? Is that just a Marine problem, or service-wide?
        Oh, and if I can brag on him, he carried in addition to his pack, and M2 receiver for an entire 20K at Pendleton without ever calling, “Fresh meat”or setting it down, the only one in his company to make it all the way. I just hope and pray that when they take a college grad like him who joins as enlisted to do it the hard way, that the bureaucracy won’t turn its back on his idealism a la Doherty & Woods.

Comments are closed.