USMC to replace M249 SAW with M27 IAR reports that the Marines will be replacing the M249 SAW with the M27 Infantry Automatic Rifle.

Marine infantry squads will replace their M249 light machine gun with a highly accurate, auto rifle geared for fast-moving assaults. In late May, Gen. James Amos, commandant of the Marine Corps, approved a plan to field the M27 Infantry Automatic Rifle to all Marine infantry battalions.

“In the training, the Marines were employing it in the semi-auto mode until they closed within 100 meters or so of the enemy and then switch to full auto to provide very accurate high rates of fire,” he added. “We don’t lose the ability to gain fire superiority.”

The H&K IAR on display at SHOT Show

I suspect the M249 is only being replaced in certain circumstances, rather than the dumping of the light machine gun for good.

[ Many thanks to Lance for emailing me the link. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Entropy

    Ok, I’m confused here. They plan to use an assault rifle as an LMG. What makes the IAR so much better in this role than an M16 or M4, and why can’t existing M16s be used in this role?

    I thought the whole purpose of LMGs was to provide high volumes of fire, usually with the use of enormous linked belts and a high rate of fire. It’s the reason the British Army replaced the L86 with the M249 in this role, because the L86 is no good for for continuous fire.

  • Saint Dude

    I remember reading somewhere ( that they’ll keep nine SAWs per company, or some similar number, in case they need some extra lead down range.

  • Guardsman26

    I find the adoption of the M27 bizarre. Is there any way to see this other than as HK416 adoption through the back door? I wonder if the M27 will be adopted more widely and replace not only the 5.56 mm Minimi but also the M16?

    I also wonder if the USMC neeeds a heavier light machine gun for a general fire support role. Will it adopt the Mk 48 7.62 mm Minimi?

    Whatever, the Hk416 and Mk 48 machine gun seem to be the current gold standards of infantry weapons.

  • Bima86

    I love the look of this weapon, but will it have the same performance as the M249?

    I’m more concerned about the sustained fire rate this weapon can provide, will it adopt a 30 round magazine or maybe a 100 rounds C-Mag.
    I know that the M249 can suppress fire an enemy position really well with its hi-capacity box magazine..

  • SoulTown

    My feelings about HK aside, still not convinced about the concept itself… What’s wrong with going the PKM route? The contractor types seem to think it’s a great idea…

  • Jim J

    Its a great weapon, once one has hands on experience with it and sees the concept completly blow the SAW out of the water its very impressive. I wish it was the standard service rifle.

  • Andrew

    Meanwhile at HK

  • What a horrible change. This is because most units use their saws like big M16s. It’s a different weapon system and needs to be used differently. This weapon has almost no advantage to the saw, except weight. A saw used correctly can be just as accurate in the field as an M4. Now squads have no heavy firepower capability.

    A replacement for a saw still needs to be belt fed, open bolt with a quick change barrel option. And of course select and/or full auto. LWCA had an interesting concept of an M4 with an option of firing from an open bolt. There are some weird conversion options that let an M4 be converted to be able to be belt fed. Combine a couple of those ideas and there could be something incredible.

    But, I don’t blame manufactures for not wanting to put a ton of research into a new weapon after the SCAR program. What a mess, and this is development of a weapon system that can’t sold to the public.

  • Theodoric

    I’m still betting on a stealth replacement of the M4 and M16.
    16.5 inch barrel, gas system, retractable stock, integrated rail system, non-burst-limited trigger group; if you accept its calibre, it’s the perfect general-issue assault rifle.

  • Leo Atrox

    You are correct. The M249 will remain in the Marine Corps ToE. Having been removed from service at the squad level, they will remain at the platoon level.

  • crisara722

    can anyone tellme wich are the main reason why they want to change the m249, and wich are the main advantages of the IAR over the last.


  • charles222

    Sounds good.

  • Paul

    It wouldn’t surprise me if weight played a factor. The M249 is quite heavy. If it’s not needed for the type of fighting they are doing, than carrying less weight would be a welcome change.

  • Erwos

    Could someone explain to me what this actually brings to the table, versus, say, an M4A1?

  • Lance

    Nice pic I see they now have bayonet lugs. This is really a attempt to get the H&K 416 ready for fielding as a standard issue rifle. I never liked the SAW I also thought a M-240/M-60 was better weapon anyway.

  • JH1990

    The unit that just replaced us in afghan had them. Not a bad concept they just need quad stack mags, or a reliable drum (Not the Cmag). They also need a better bipod….

  • Avery

    Didn’t we have “Rambo” just a while back tell us that when you get into a mad-minute situation such as a counter-ambush or defending a crash helicopter, that you want essentially uninterrupted fire and magazines slow you down?

    It sounds like the Marines are developing tactics around the IAR, but, until the Marines issue out C-Mags or get ahold of quad-stacks for their SAW gunners (the former is likely), the IAR is incapable of matching the volume of fire of a belt-fed machinegun.

  • Jeff

    Isn’t a belt of 200 better than a mag of 30 when you are on ‘rock and roll’ mode?

  • JT

    I can see if it were augmenting the m249, but replacing? Do they have another SAW that would be there as well? How would they swap out barrels? Would they keep extra barreled-upper receivers with them?

    Maybe this has something to do with the new Magpul 100 rounders that are coming out.

  • Raoul O’Shaughnessy

    Nice tactic…and, unsurprisingly, every marine will suddenly be a former SAW gunner. Nice end run.

  • soless

    Now they have to start stocking up on the Surefire 100rd mags! That’s if this does follow through.

  • j

    this comment probably sounds stupid, but could we replace it with a gun that isn’t 5.56?

  • Flounder

    I just do not understand why the marines are switching out the saw for what looks like pretty much just a full auto M4… I mean it runs off of mags so its not like they gained any capacity over the 100 rd belts. Yeah it is lighter but so is an M4… It’s not like you can switch out the barrels. Oh Yeah I read the original report on that’s where I got the above tidbit.

    Maybe you can clear up why the saw is being replaced with this.

  • j

    maybe 7.62×39
    even though i don’t like that caliber

  • Matthew Carberry

    The fireteam position IS called Automatic Rifleman after all.

    It would make sense for the Asst. AR to carry a couple C-Mags (or whatever hicap is acceptably reliable) to give sustained fire capability for a hasty defense or supportive fire.

    The AR wouldn’t replace the SAW in absolute capability for a sustained dug-in defense, but shoehorning what at root is a crew-served LMG into the AR role wasn’t ideal for most of what the Marine infantry squad does; locate, close with and destroy the enemy with fire and maneuver or repel the enemy’s assault with fire and close combat.

    When it comes time to dig in there’s time to bring out the SAWs and Golfs.

  • Sev

    but what about suppressing fire? a 30rd mag isn’t exactly enough and the US military doesn’t (at least to my knowledge) use 100 round Beta C mags.

  • Lance

    @ Flounder

    The IAR is not to replace the M-16A4 its actually heavier and has a lot more heavier barrel than a standard m-4 or M-4A1. Yes they haven’t got the mags for them threw the politics yet buts doing a good job and just give time for Marines to find a decent high cap mag for it.

    As for the SAW I never liked the idea I always thought a GPMG like a M-240 or M-60 was far better in support due to its 7.62mm firepower in support is far better than 5.56mm wimpy firepower for support. I don’t think the regular military will go with the Mk-48 since they just got done developing the M-240L light weight GPMG.

  • charles222

    Yeah, the regular military is never going to adopt the Mk. 48 because of increased occurance of parts breakage.

    Anyway, this weapon is literally just about perfect. Yes it’s not belt-fed BUT belt feed is actually disadvantageous in quite a few ways; all it has going for it is continuance of fire. You can’t reload a SAW on the move, the 100-round drum is NOT a particularly long-lasting quantity of ammo, the 200-rounder adds even more weight to what’s already a heavy weapon, and even just basic reloading under cover is a slow process with about five steps. It’s a junk-ass weapon as far as a MOUT situation is concerned and with something like 3/4ths of the world’s population living in urban environments, yes this is a concern. Leave the sustained fire role to the platoon’s M240s and give the automatic rifleman a weapon that integrates him better with the rest of the fire team.

  • jdun1911

    There is no reliable 100 rd magazine, especially when you are dealing with high constant cycle rate. I’m not even sure if 60 rd magazines are reliable to depend your life on.

  • Rohan

    Enjoy your C-mags at 4.6lbs loaded with 100 rounds.

    That’s equal to 4 1/2 30rd magazines (135rounds)!

    The M16A4 weights in at 7.5lb, the M27 in at 7.9lb.

    Nearly the same weight, but the M27 has its mass in a thicker 16″ barrel.

    The fireteam position IS called Automatic Rifleman.

    His job is to stay with his fireteam, fast and light.

    “The M249 is quite heavy”

    Actually it’s only 17lb, (Mk26 13lb), the M240 is heavy at 26lb (Mk48 18lb)

    There is a machine gun squad in the company weapons platoon with six M240, machine gun trained crew (MOS 0331) with tripods.

    Anybody who suggests issuing 7.62mm MGs down fireteams with M240 / M60 has never carried one (23-26lb plus 400-600 rounds at 26-38lbs).

  • Rijoenpial

    Hi guys!

    To Lance: the USSOCOM has the Mk48 in their inventory, so why not ask them or follow their lead?

    Also, the HK’s IAR shortcomings clearly demonstrate how rigged the entire thing was: the mere fact that you have no ability to change barrels, and in so having to be aware of the cyclic rate of fire in order to prevent problems, such as cook-offs, is ridiculous, since for instance FN’s contender, the HAMR, does not present those shortcomingsa and even has a clever system to prevent just that!

    I also find it hilarious to select a replacement for the SAW that clearly lacks the most important thing: firepower, be it in terms of quantity (30 rounders?! Come on!) and in terms of quality (no interchangeable barrel, having to reduce cyclic rate to prevent cook-offs!)

    The mere fact that the soldier needs to carry 22 mags clearly shows how hasty and ill advised this project was devised and carried out! So, they will reach the SAW’s weight with the weight of all those mags! I can’t even imagine how will that poor soldier carry all those!

    I have my hopes on the SAW-MAG and the hope that it will be used by the troops as soon as possible because I can imagine a Taliban using a Soviet LMG and vaporising the pee shooters with their 30-round ‘LMGs’…

    IF accuracy was really the deciding factor, they would have used the M16A4s or the M4s with a good scope and/or re-institute the 3-round burst and full-auto capabilities onto the M4!

    My point is that this rifle being adopted makes little to no sense, unless it has been done to circumvent the bureaucracy and allow for a HK416 into the inventory! Because this IAR is nothing more than an HK416 with full-auto capabilities and a heavier barrel!

    Full-Auto in a weapon with only 30-round magazines in it, is hilarious! To have it being fielded without a proper magazine option for suppressing fire, I am guessing that the M249 will be around for a while, because it is just a matter of time before the brass realise that this was a poor, poor decision! Hopefully, a decision that won’t cost lives!


  • Pete Sheppard

    The USMC squad has three fire teams; the Army, two. In a basic “fire and maneuver” situation, the Marines will maneuver one FT, with the other two providing the base of fire. Two IARs in this setting will provide equivalent support to the one SAW of an Army squad, where there is only one FT providing BoF for the maneuvering FT. Given this difference, the SAW makes sense for the Army squad–which is also oriented to mechanized movement, rather than foot.

    Keep in mind also, that rarely will a squad be completely on its own, but will be working with its parent platoon/vehicles, so the PLT/transport will be providing the REAL Base of Fire.

    Of course reality rarely matches the dream. Murphy hates dreams…

  • Andy from West Haven

    Sorry, rather have the 249. But if they were issuing quad stack 60 rounders with those HK’s it would be a bit better. Those 100 rounders are dumb.

    Better off with a C-mag or the new 150 round drums I saw. Yeah, I know people say they work or they don’t. And I know that people that shell out the money for them don’t want to be embarassed by posting a Youtube vid of it jamming. But when I see the Youtube vids where they mash the trigger down and all 100 and 150 rounds go flawlessly, it makes you feel all warm and fuzzy inside.

    Ooooh, better yet. A 249 in .300 BLK… Be lighter than the 7.62 version and still pack 200 rounds. Alas, 5.56 isn’t going anywhere anytime soon.

  • El Gato

    It looks like the Marines finally read the Army’s initial critique of the M-16A2. Let’s hope three round burst goes away. It really throws off the weight of pull in semi auto.

  • Gabe

    Sort of seems like a development of the BAR weapons system. Not in function but in the role the upper military echelon wants it to fill. I dunno if thats a good idea πŸ˜›

  • armed_partisan

    I’m glad to see I’m not the only one who thinks this is a stupid idea and at best a back door attempt at replacing the M-16A4 with a front piston driven M-4 clone. I think the Colt IAR was a much better version of the same concept, and if someone can explain to me why the Ultimax 100 isn’t a better choice still, I’d love to hear the details.

  • Rijoenpial

    Oops, almost forgot: Regarding the mags available for the IAR, the only one that looks promising is the aforementioned SAW-MAG from Armatac Industries… Regarding the Surefire 60 and 100 round mags, the Vuurwapen Blog guy realised by mistake that their followers are prone for jamming, since they are NOT non-tilting followers! Major bummer! The Beta-C Mag is the crap we all know about and the there isn’t much else except Magpul’s still vaporware quad-stack mags…! of course, they can have four mags clamped together, so that would be faster but totally cumbersome for the operator!

    My guess is that if they want this IAR to work, they will need to alter the design to make it new barrel-friendly, change the closed bolt nonsense to either a dual system like the LWRC or like the FN HAMR, a system that changes from closed bolt to open bolt automatically!

    I can’t understand the choice of the HK’s very limited design, unless for the reason I and other fellow posters presented before!

    In a word, another proof that the Brass is playing with soldiers lives, by giving them unequivocally lawed designs that may well unacceptably cost some of their soldiers’ lives!

    They really need to stop wasting the taxpayers money and playing with soldiers lives like this!


  • Flounder

    @ Lance
    I think you misunderstand my point. In my opinion and to my knowledge the IAR is halfway between an M4 and a SAW yet it seems to have the advantages of neither. Then again i’m not well versed in the tactics of the marines.

    Another problem that’s been bugging me is that the IAR cannot switch out barrels to sustain a high rate of fire like the SAW can. So does it even matter that it currently only runs off of 30 mags? Seems like if it’s capacity was as high as the SAW’s it would overheat the barrel real quick. On the soldiers who were part of the test fielding of the IAR noted that you had to keep the amount of fire down and they carried 22 30round mags. Thats right 22 different mags! Not sure if that’s awesome or ridiculus.

  • Big Daddy

    There are many different tactical environments. No one weapon can cover all of them except your basic battle rifle. Any military NEEDS to have overlapping weapon systems. This is just that, it bridges a gap between the M-4/M-16 and the M-249.

    Bravo to the Marines with their MK M-27 and the M-32, they try with so much less funding to give their troops the weapons they need. Not some magical mystical POS the Army always seems to come up with like the M-25 and M-320.

  • Ferrus Manus

    Maybe they are going to buy some HK MG4 or HK 121 next.

  • Avery

    @JT and soless:

    I’m pretty sure you know those 100-round magazines (just going off what Surefire has on the market) would become an impromptu pintle mount for the IAR. They’re ridiculously long. It’s going to be Beta C-Mags or Armatac SAW-MAG if they want something other than the USGI standard issue, because the gunner would not be able to go prone with the IAR if their using the Surefire magazines.

    The Surefire 60-rounders might work, but it alleviates the issue just a bit.

  • Jim J

    Most SAW gunners lay down a large volume of inaccurate fire, with the IAR and the SDO they lay down a much more accurate equal volume of fire while carrying less weight. Yes new training/Tactics will be developed but the concept is valid I didn’t believe it until i viewed it either. It really works and when the whole fire team reaches the objective the Saw gunner isnt much more worn out then the rest of the team. The key in the environments i fight in today is speed, endurance, and accuracy from what ive seen in my opinion the IAR improves these elements dramatically. Its not the Cold War any more its highly unlikely battles will be waged by groups any larger then the company level and even that is rare.

  • Jim J

    not to mention IARs shoot about 1 MOA with M855.

  • Matthew Carberry

    Remember, unlike the Army, the primary unit of maneuver for Marine infantry is not the squad but the 4 man fireteam. The Team Leader with his pocket artillery of the 203, the Rifleman to carry batteries πŸ˜‰ , the Automatic Rifleman who, when the concept was created had a BAR, not a machinegun, and the Asst. AR who carries more ammo for the AR.

    A true machinegun was never part of the plan, the -60 and then the 249 were shoehorned in due to lack of a good AR option when the M-14 wasn’t up to snuff in the ’70s.

    With three teams per squad that gives you two 203’s, two AR’s and 4 rifles, plus the squad leader, “suppressing” while the third team moves. None of whom are burdened by a weapon that, realistically, is less than optimal for getting hits from an unsupported position. “I’m up, he sees me, I’m down” sucks with the SAW, much less the 240.

    When operating as a platoon you have the same thing x3 and in that kind of op you’d likely have guns from the weapons platoon along and distributed as attachments.

    Anyway, it’s all about offensive maneuver at that level. All that is really needed is a reliable hi-cap mag for the AR for sustained fire while the rifles change mags.

  • Burnzy8

    Lance, I remember someone floated the idea that the M27 was backdoor way for the Marines to replace the M4 and M16. Could be total BS but maybe not. If they could add a ceramic heat shield to the gas plug so the hand guard doesn’t heat up excessively and use one of those newfangled self-lubricating surface treatments for the barrel and moving parts it would be even sweeter.

    If the new blacktip 855a1 ammo actually does what the army says it does, far from a sure thing I know, but if it does then the M27 just might get the job done.

  • Michael Loyd

    Maybe you guys dont know what the M27 is….comparing it to the M4 makes absolutely no sense because aside from their similarity in apperance, they dont have much in common. Nothing is similar about the two weapons except the receiver type and caliber size. The M27 is free floated(barrel harmonics), has a higher cooling capacity(due to its free float design), is piston operated, and has a highly enhanced recoil reducing system. Although they may look a like, they are in fact not similar. I’d like for you to find a SAW gunner who has had to replace their barrel in any situation. Machine gunners who exploy their weapons at the cyclic rate in any situation should be jacked up by the section leader.The commandant of the Marine Corps spoke to our graduating TBS class and spoke about how he himself but a five round burst on target from 500m. There isn’t a SAW gunner in the world who can do that. All you guys talking about fire superiority must not understand that rounds down range dont count for anything. Suppression isnt suppression until its accurate. If you are saying we are going to scary the enemy into not maneuvering because of rounds down range, then then apply that logic to our current enemy who employ tactics that result in volume of fire without accuracy. Saw gunners tend to over exaggerate how well they shoot with the SAW. What I dont know is that the M27 is 10lbs lighter than the SAW which is an advantage i’d take anyday considering the SAW gunners are usually the ones who cant keep up to everyone else. You wont find many active duty Marines arguing against the M27.

  • Matthew Carberry

    I was on a recon team, not in a leg infantry unit, but we never took the spare barrel and bag out on patrols. 3 to 5 round aimed bursts won’t overheat the barrel. The only time I can see actually changing one out during a firefight is in some Ft. Apache FPF situation where you are locked in with a T&E and just making a wall of lead.

    One thing M. Loyd, are you saying a SAW gunner can’t regularly -hit- a target at 500 or farther with a 5-ish round burst (off the bipod) or they can’t keep them all -on- the target at 500?

    I’d agree with the latter but the former is wrong in my experience.

  • Lance

    They are not replacing the A4 with the IAR its heavier and barrel is shorter than what the Marines want now in the future they buy a 20 inch 416 who knows. The Mk-48 has some reliability and parts breakage problems and since the Army just adopted the light weight M-240L the 48 isn’t going anywhere.

  • GySgt Barnes A, J.

    Read @Pete Sheppard’s comment up there^^^ He know’s what he’s talking about.

    I’ve been in the Corps for 12 years and I’ve had to go into combat with the SAW and the 240b several times, and it’s a pain in the ass. Try reloading or swapping out barrels while getting pounded by 7.62x39mm and 7.62x54mm rounds. It sucks and then when you’re done the only thing you have to throw back is those pewnie 5.56mm pellets from a weapon that weighs 22 pounds fully loaded. You already have 50 pounds of armor 3 extra 200 round ammo pouches. I also always went out with my personal R-870 tactical and my Colt m-1911. plus the other 40 pounds of other random gear. 5 pound kevlar on your head… That SAW sucks.. Forget about the 240 bravo and especially forget the m60..

    I would much rather have the m27… But Personally if we’re going to go from an LMG to an AR I think we need to bring back battle rifles like the m-14 or use the FAL or G3. I’d rather have a 7.62x51mm round to throw around.

  • Rohan

    Time shall tell.

    If the M27 is so hot; super barrel, piston and recoil system, why are the Corps persisting with M16A4.

    5 rounds into one target is not suppressive fire but a waste of 4 rounds. If you can see a target, kill it. If not suppress it and stop it manoeuvring and engaging you.

    If its so good with ammo, why are you still carrying the same amount of ammo as the current SAW gunner (660 ball vs 600 link). That’s still 20 pounds of ammo, either way.

    Mk46 would save 5lb, and half the so called savings of the M27. It suits SOCOM and they operate of small teams.

    I’d like for you to find a SAW gunner who has had to replace their barrel in any situation.

    I would in defence, every chance I had. No more “Battle of Wanat” and fusing M249s.

    Anyway, it’s all about offensive maneuver at that level. All that is really needed is a reliable hi-cap mag for the AR for sustained fire while the rifles change mags.

    It’s called belt feed. Drums, quadstacks, C-mags don’t work in the real world.

    Wasn’t the M249 adopted as THE SAW, and had none of the short comings of the BAR, ie belt feed and quick change barrel option, back in the 80’s?

  • Rohan

    There, the defenders used whatever weapons were available to them,
    firing personal weapons furiously into the nearby trees and aiming 40-
    mm grenades at more distant enemy positions. Without any machine
    guns of their own, the mortarmen had to use M4 assault rifles firing at the
    maximum rate of fire simply to suppress the enemy in order to survive.
    In this way, Phillips burned out a series of three M4s. He then picked up
    an M249 SAW belonging to the engineers and tried to fire it but it failed
    to shoot. Mortarman Queck had previously tried to fire the SAW but it
    was jammed. Another trooper later fired it successfully after changing its

    US Army Combined Arms Centre

  • Jim J

    For all you arm chair commandos or pogs there is no need for a quick change barrel its not World War II if you putting that many rounds down range that fast your messed up and have no training whatsoever. If your clearing a room with an open bolt belt fed weapon you are slow and stand a large chance of malfunction. In fixed positions we use 240s, Mk19s and the occasional Saw. On todays battlefield we are constantly on the move. Some people seem completly oblivious as to the way we fight today.

  • subase

    I think it’s just a response to the combat conditions on the ground. If the M249’s main purpose is suppression for movement, it must mean there is no longer any need for suppression for movement. The enemy is attacking from such a long distance away that moving around or towards them is a non issue. And of course the weight load of marines makes the idea of them running after the enemy laughable. Then there’s CQB. I do think this is a back door attempt to make the HK416 standard for the marines, but there does seem to be alot of good reasons for dumping M249 use in Afghanistan. And of course this enhanced HK417 is just a superior weapon to the M16/M4 with identical manual of arms, so no complaints.

  • Lance

    The Mk-48 might be also replace in SOCOM service by the new M-240L the new M-240L is about the same weight as a LMG but fire 7.62mm NATO and uses all same M-240B parts except the receiver which is titanium. That the new GPMG the Mk-48 isn’t going anywhere.

  • Rohan

    The Marines of 1st Force never carry the spare barrel. It is unnecessary when compared to the mission essential gear required for a deep reconnaissance mission. While it can be successfully argued that the M249 is problematic and temperamental, Ist Force has had no problems carrying the M249 (para) in condition three (that is-bolt to the rear, chamber empty, mechanical safety off. The primary safeties-the operator’s brain and a straight trigger finger-are always engaged.) Force uses the M249 (para) as a base of fire weapon-at the rate of one per six-man team. Consider that during deep reconnaissance, they will be without benefit of supporting arms in the deep battle area. They can depend on no one but themselves to dominate or break contact with the bad guys. The reconnaissance team must have something that can deliver accurate automatic fire at the sustained rate. The M249 (para) may not be without faults, but until something significantly better comes along, it is a good weapon for the company.

  • Matthew Carberry

    This isn’t any conspiracy. It’s simply finally fixing a 50 year old TO&E problem. The SAW (Squad Automatic Weapon) is an LMG. LMG’s were designed to facilitate squad-level MG-based infantry tactics. More or less what the Germans developed in the latter part of WWI.

    Fire team tactics were a response to the evolution of semi-auto battle rifles, which put more firepower into the hands of the individual riflemen, reducing the need for an actual MG, which required a crew, to gain fire superiority. The BAR filled the new role of Automatic Rifle at the fire team level in US forces until after Korea, when the limited mag capacity and weight of the BAR became a problem. Also, we were going from the .30 Garand rifle to a new round and needed a new rifle and AR system.

    The full auto M14 AR turned out not to be any lighter or more controllable (less maybe due to a faster cyclic rate) than the BAR in the AR role and still only had 20 rounds. So a medium MG, the -60, the closest thing we had laying around, was shoehorned into the role and stuck even as the 7.62 rifle gave way to the 5.56.

    The -60 was old and finicky and as a general purpose (medium) MG was completely wrong for the AR role and now no longer even had ammo compatability at the fireteam level. Ad hoc M-16 AR’s were tried (with that clamp-on bipod) in Vietnam but proved unsatisfactory (too light a barrel?) Thus the SAW. It was lighter, shot the same round and was less unwieldy but it was still a belt-fed, crew-served support weapon shoved into an automatic rifle, light and handy for the assault, position.

    Anyway, as I recall the MC Gazette articles from the ’90s, that’s the history of the “lack of an AR” problem, for the Marine Corps at least. There was talk almost 20 years ago of needing a heavy-barrel FA M-16 variant to replace the short-comings of the SAW in the AR role.

    This isn’t a surprise but a possible solution a long time coming.

  • Daniel

    Big Daddy on 17 Jun 2011 at 7:57 am

    There are many different tactical environments. No one weapon can cover all of them except your basic battle rifle. Any military NEEDS to have overlapping weapon systems. This is just that, it bridges a gap between the M-4/M-16 and the M-249.


    Which is why I prefered the Ultimax, given a bit of time and parts to configure, you can go from SMG, Heavy Assault Rifle, baby SAW and in some African countries, limited range sniper SAW. Hell, given that it can be fired single handedly, maybe you can even go as low as a super heavy handgun.

    The M-27 does fill in the gap between AR and SAW, but it just doesn’t reach far enough to cover the SAW role in a pinch.

    And the fact that the U100 doesn’t kick off target even on FA after the 4th+ round really impresses me. No more “lower to the left” crap, now you can AIM at where you want to hit.

  • Flexibility

    I’d like to add my 2 cents. I think Big Daddy is the guy that is right on. I am a big SAW fan. I’ve read and heard the whining about weight and jams and changing barrels and the fact that its belt fed.

    A quick note about weight. It doesn’t weigh that much. I vote to keep the weight discussion limited to the amount of Iron Man 2 body protection gear that needs to be worn in this common day and age. Make the infantryman a little lighter and more mobile and an extra pound or two to the weapon won’t be a big deal.

    But back to Big Daddy’s point. We spend so much money on different weapons systems that have nothing to do with a Grunt (40 different drones, vehicles, planes blah blah) that there is no reason why the Corps cannot spend some dough on fielding different systems for different operating environments for the grunts. I’ve been told before that you can’t train a Grunt on different systems and that is just total BS. Considering that I was an 0311 before transitioning to a 31, I was trained on a multitude of systems and new every one of them well.

    We can be better and more flexible Grunts. In urban terrain, the SAW was an asset, but I reorganized my Squad to keep the SAW gunners in support. Depending on the situation, I would put one in the assault team or leave all three in Support. I always had a lot of firepower at my disposal if it hit the fan. I could put those 3 gunners on the rooftops and maneuver my squad under a rain of fire in the assault. The rounds may not have penetrated the wall, but no one behind them was moving very much.

    The IAR would give me a little more flexibility in urban terrain….(Having never touched or fielded it…this is a guess). I believe I could leave the infantry squad native instead of having to revise my tactics to accommodate the weapon system.

    Having been to Panama (post invasion), I personally wouldn’t dare enter a jungle environment without the SAW’s. You wouldn’t even need a scope. You can’t see anything for more then 30 meters if you are lucky. Sitting in the defense with 3 belt fed high cyclic rate weapons per squad makes daddy feel better at night if someone was going to attack me.

    Now, we could insert Gunny Barne’s argument about the caliber into this scenario and the ability to cut down jungle with a 5.56. But the debate isn’t even worth having. It’s probably not going to change soon, but I agree. For now, I’ll keep my SAW.

    So my vote is to field the M27. Field the SAW. Field the A4 and the M4 for Iraq vs. Stan environments. Train each 11 on two different weapons systems. Have them overlap, or keep them separate. Let the Battalion Commander determine which weapons system is best suited to which environment. But bring them all in case you guess wrong. It can be done, and it ain’t that hard. And it will all cost less then 5 Osprey’s.

    I heard that each platoon will still field SAW’s. I don’t know if that is true or not, but I don’t really understand why. So each platoon is going to have a Machine Gun squad attached and then an organic SAW squad? It doesn’t make sense to me. Having AO specific weapons for the the infantry platoon makes more sense to me. But I digress. I’m older and fatter.

  • Raider186

    Why is everyone hung up on a spare barrel for this? The Piston and rod system greatly reduces the heating of the barrel when firing, so a spare barrel is not needed.

  • oicu812

    Someone tell me what exactly the HK “IAR” has over a similarly configured M16. Anyone?

    All the HK weapon is a conversion, yep, a piston conversion of a Stoner design. It is a cobbled together POS like the rest of the conversions.

    The SAW, although not perfect, is far superior. To replace a belt fed weapon with a magazine fed weapon is retarded. How about some proper training? Anyone think of that?

    The weapon chosen should have been Knight’s LMG, a 10# belt fed that is far superior to the FN SAW.

    • H

      I just seen video of m249 in some firefight, failing to shoot cca every 10 shots… The gunner cocks it again and again, imagine this happening to you in final phase of assault.

  • Flounder

    How does the piston system run cooler than any other system? I’m really just curious as to how it does this. But then again I seem to remember watching a video of the HK416 piston being demonstrated and there was something in it about how the piston vented the hot gas out the front.

  • Sid

    Because fast maneuver and urban figthing with the SAW is less than ideal. Weight is an issue (weapon, ammo, and body armor). Also, the SAW is belt fed and that leds to more failure issues when maneuvering.

    My history with the SAW goes back to 1987 and the 7th Infantry Division (Light). The SAW is a compromise. It is lighter than the M-60/M-240 but far heavier than the M-16/M4. It is belt-fed and has a higher rate of fire than a magazine fed weapon, but that requires the gunner to carry more ammo.

    When you get down to it, you have a weapon that is a little too heavy for room-clearing and to be used as designed requires a lot of ammo to support. Remember that M-60 and now M-240 are crew-served weapons. Not because it takes more than one person to shoot, but because it takes more than one person to carry all of the ammo and help out on barrel changes. The SAW gunner has to do all that alone.

    For the operations that we are now facing, the M-27 IAR is a better choice for the moment.

  • oicu812

    Again, what does the HK piston M16 have over a similarly configured (16″ HB, auto capable) Colt M16? What?

    The rifle was not designed to have a piston slapped over the barrel. It is a conversion, period. It is heavier, more and proprietary parts, sharper recoil impulse.

    If you read my previous post, Knight’s LMG weighs 10 lbs. Yep, 10 lbs. Runs like a raped ape. Reed had it up for consideration but was rejected for some mythical “lack of manufacturing capability”.

    Supplanting a beltfed weapon with a magazine fed weapon is ludicrous, particularly when a comperable weapon – the M16 – is already in service. Perhaps some training with the belt fed weapon is in order.

  • Sid


    Because belt fed weapons are cumbersome and prone to issues when maneuvering. Not to get into a flame war, but belt fed weapons work wonderful in static positions. In static positions, feeding a belt fed weapon is possible. Manuevering makes the equation less simple. It is not a matter of training. It is a matter of belt fed ammo having issues when jostled around and flung over walls. Magazines are easier to manipulate when you are moving around.

    I don’t think the USMC is getting rid of all belt fed weapons. It is just getting rid of the squad automatic weapon. At the point where one soldier is moving around supporting his weapon, I think the M27 makes sense.

  • oicu812

    Sid –

    Ok, for arguments sake say your scenario of “belt fed weapons are cumbersome and prone to issues when maneuvering” is true, you still haven’t addressed my question I have in both my previous posts, being “What dioes the HK IAR have over a similarly configured M16”?

    Outside of that, I totally disagree with your take on belt feds, and I guess you aren’t up to speed on Knight’s LMG. You need to check it out.

    Check at around y minutes into the second video.

    I couldn’t find the video showing Reed shooting it overhead holding it with one hand. It doesn’t move. I first saw him do this at Knob Creek many years ago.

  • Sid


    The difference in the M27 and a similarly equipped M16 is that the M27 fires from the open bolt position. That design allows for much more efficient cooling of the operating action. The primary purpose of this weapon is suppressive fire. It will have to maintain higher rates of fire.

    The Stoner LMG is probably a great weapon. Not doubting you on that. I am saying that it is a better belt-fed weapon. I can’t see the powers-that-be justifying the purchase of a better belt-fed weapon. You don’t have to agree with me on the issues of manuevering with a belt-fed. I am saying that justifying the purchase when the M249 is acceptable as-is will be hard for the military to accomplish.

    On this project, they are more able to justify the purchase because they are responding to a battlefield need to replace a belt-fed with a magazine fed weapon.

    I really like KAC products. I also like Barrett products. If you are ever in my neck of the woods, let’s go shoot my 6.8mm Barrett. Or have a drink.

  • Very neat post.Really thank you! Want more.

  • David

    My son is currently in SOI. he says they are being told the IAR will eventually replace the M16/M4. The SAW will be kept as a LMG, 6 per company.

    • Lance

      Thats not the case the USMC is going in a few years to make a M-16A5 and the IAR will replace most SAWs. The Army and USMC will buy M-4 and M-4A1s as well for select units.