Marines to start fielding the M27 Infantry Automatic Rifle.

I guess it was a couple years ago when I first started hearing serious rumblings about unhappiness in the Marines over the M249 Squad Automatic Weapon. In the close urban terrain of the cities of Iraq, Marines were spending a lot of time kicking in doors and rushing into rooms. Well, the SAW is an 18 pound weapon empty. Add a 200 round drum, and maybe some other accessories, and pretty soon, it’s tough to see using it in a close in fight like inside a building. Lots of Marines were agitating to replace the SAW with a lighter, shorter automatic weapon.

Looks like that is going to happen, at least for some of them.

In March interview with, then Commandant Gen. James Conway cast doubt on the utility of the IAR, saying the service had to wait and see whether it should be adopted. But field tests performed in Twentynine Palms, Calif., last summer turned skeptics into converts.

At a recent “town hall” meeting at Quantico, incoming Commandant Gen. Jim Amos raved about the M-27, saying it’s in the running to replace all SAWs in the inventory.

“I fired the [IAR] … and this thing could — notice I didn’t say ‘would’ — could replace the SAW,” Amos said. “Any of you grunts in here who have not fired that weapon, you need to fire that weapon.”

“Fighter pilot old man here fired it and I put it in about [six inches] at 500 yards,” Amos added. “It’s an incredible weapon.”


The M27 is a hybrid of a couple different weapons. The lower receiver/trigger group is straight from the M16/M4 family. The upper receiver is lifted from the HK416. The 16” barrel is heavier than most rifle barrels to allow for greater sustained fire. It fires the same 5.56x45mm rounds as the SAW and the M16/M4 family of weapons, from the same 30 round magazines.  The vertical grip on the forearm conceals a collapsible bipod for shooting from the prone.

It’s pretty ironic that this is happening as the Marines are wrapping up in Iraq, and ramping up their operations in Afghanistan, where longer range fights are the norm. Just as the need for a smaller weapon has diminished, and the long range, high volume of firepower of the SAW is coming into its own, the Marines are going to switch some weapons out for a lighter piece that won’t have the same ability to lay volume suppressive fires. You’ll note the new Commandant talks about how accurate the M27 is at long range. Well, I always thought the M249 was pretty damn accurate at 500m, and even out to 800 meters, hitting a point target was easy.

The guys at The Firearm Blog chewed over the weapon in the comments. One interesting “conspiracy theory” popped up. The Marines have never liked the M4 carbine for their infantry. Most Marine infantry riflemen carry an M16A4.  But the M27 is a lightweight weapon, it’s short and handy, and it has a gas piston operating system. Is it possible the Marines are looking for a backdoor way of replacing their M16s with a piston weapon? Maybe.

Based on the comments in the latest post over there, it doesn’t seem a popular move to replace the SAW in the Marines.

8 thoughts on “Marines to start fielding the M27 Infantry Automatic Rifle.”

  1. Hmm. Lighter, 5.56x45mm; 30 round magazine? Don’t we have a couple hundred thousand M16A1s sitting around somewhere still? Throw a bipod on, and there is your autorifle… Oh wait, we already did that but traded it in for the SAW in the 80s.
    SAWs have gotten pretty small and pretty light over the years; I am still good with keeping it around.

  2. Since Badgers not only drink HK Kool-Aid, we guzzle it, I find myself giving my approval! HUZZAH! 🙂

  3. Given the ranges involved in AF, perhaps a HK 417 would be a better choice, however. 7.62 NATO does allow one to reach out farther.

  4. Well, the Marines already have any number of 7.62mm weapons in theater, from M240s to various 7.62mm sniper weapons. But there’s always a balance between weight, mobility, and firepower. Everything you’d gain in terminal performance, you’d lose in volume of fire.

    I think the IAR would have made a good deal of sense in Iraq. Or at least swapping out the SAW in one or two of the fire teams in a squad (the Marines use three fire teams in a squad, the Army, two). But I don’t think it is going to be as useful in Afghanistan.

  5. Not being an infantry/airborne type to be kept in mind.
    It does look as though it may fill the bill. Lighter but as capable.

  6. But it is NOT as capable. It can provide a greater sustained volume of fire than an M16, but because it is magazine fed, it can’t provide anywhere near the sustained volume of fire of a SAW. And it has no provision for quick change barrel. IIRC, the Army doesn’t usually carry spare barrels, but the Marines do.

  7. I would not change the SAW for the IAR in AFG. I like the piston gas system (the lack of which is a serious problem with the Stoner designed weapon). But, there is a good reason behind the semi-jest of “happiness is a belt fed weapon.” You can hang high capcity mags on the AR-15 action, but the system will not stand up to the stress of sustained high rates of fire. Hanging a heavy barrel on the action helps, but that’s all it does. There’s good reason why modern GPMGs have quick changing barrels.

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