The US Marine Corps has established one battalion (3rd Battalion, 5th Marines, 1st Mar Div) as an experimental, testbed unit, and that unit is looking at some possible new small arms approaches. The first of these is a more general issue of the M27, currently used as the Infantry Automatic Rifle (IAR) with one per Marine infantry fire team.


The concept under test would replace all the M4s in the rifle squad with the M27, which is a version of the HK 416 with a couple of USMC-requested mods, like a bayonet lug. reports:

Chief Warrant Officer 5 Christian Wade, the gunner, or infantry weapons officer, for 2nd Marine Division, told the M27 costs about $3,000 apiece, without the sight. Because the Marine Corps is still grappling with budget cutbacks, he said he was skeptical that the service could find enough in the budget to equip all battalions with the weapons. He said a smaller rollout might be more feasible.

“To give everyone in a Marine rifle squad [the IAR], that might be worth it,” he said.


[Commander of 1st Marine Division, Maj. Gen. Daniel] O’Donohue said feedback would be collected on an ongoing basis from the Marines in 3/5 as they continued workup exercises and deployed next year. Decisions on whether to field a new service weapon or reorganize the rifle squad would be made by the commandant, Gen. Robert Neller, when he felt he had collected enough information, ODonohue said.

If the Marine Corps can sort out the logistics of fielding, Wade said he would welcome the change.

“It is the best infantry rifle in the world, hands down,” Wade said of the IAR. “Better than anything Russia has, its better than anything we have, its better than anything China has. Its world-class.”

If there’s an obstacle, it’s cost-effectiveness. The best is the enemy of the good, and the M4 delivers a good 95% of what the M27 can offer. But the Marines seem certain that they can exploit the incremental improvement in accuracy that comes with the free-floated barrel and

There’s much more to it than that, so do Read The Whole Thing™.

Meanwhile, another test unit (B/1/2nd Marines) is going to go 100% suppressed, from carbines to heavy MGs, to see how that works. Also

“What we’ve found so far is it revolutionizes the way we fight,” [commanding general of 2nd Marine Division, Maj. Gen. John] Love told “It used to be a squad would be dispersed out over maybe 100 yards, so the squad leader couldn’t really communicate with the members at the far end because of all the noise of the weapons. Now they can actually just communicate, and be able to command and control and effectively direct those fires.”

A Marine from B/1/2 Marines fires an M4 with a Knight's Armament Company suppressor attached.

A Marine from B/1/2 Marines fires an M4 with a Knight’s Armament Company suppressor attached.

Chief Warrant Officer 5 Christian Wade, the division’s gunner, or infantry weapons officer, said the Lima companies in two other battalions — 3rd Battalion, 6th Marines, and 3rd Battalion, 8th Marines — now had silencers, or suppressors, on all their rifles, including the M27 infantry automatic rifles. All units are set to deploy in coming months. The combat engineer platoons that are attached to these units and will deploy with them will also carry suppressed weapons, he said.

The Marines are discovering, as SOF (including Marine SOF) discovered some time ago, that the benefits from going quiet are not just the obvious ones.

“It increases their ability to command and control, to coordinate with each other,” Wade told “They shoot better, because they can focus more, and they get more discipline with their fire.”

The noise of gunfire can create an artificial stimulus that gives the illusion of effectiveness, he said. When it’s taken away, he explained, Marines pay more attention to their shooting and its effect on target.

“They’ve got to get up and look, see what effect they’re having on the enemy because you can’t hear it,” he said.

He added that suppressors were already in common use by near-peer militaries, including those of Russia and China.

Wade said he is working on putting suppressors on the Marines’ M249 light machine gun and M240G medium machine gun, using equipment from Marine Corps Forces Special Operations Command. The third and final objective will be the suppression of the .50 caliber heavy machine gun, he said.

The Marines are showing, in this as in the IAR experiment, a real commitment to experiment-driven (and therefore, data-driven) procurement decisions, which is an interesting contrast to the other services’ way of doing things. Rather than hire a Federally Funded Research and Development Center like the Rand Corporation or Institute for Defense Analyses to write a jeezly white paper, they put the stuff in the hands of real mud Marines and see what use they make of it.

And then they write the report.

As the units conduct training and exercises with suppressors, 2nd Marine Division is collaborating with the Marine Corps Warfighting Lab to collect and aggregate data. Weapons with suppressors require additional maintenance and cleaning to prevent fouling, and the cost, nearly $700,000 to outfit an infantry battalion, might give planners pause.

But Wade said he will continue to gather data for the next year-and-a-half, following the units as they deploy. And he expects the idea to have gained significant traction among Marine Corps leadership by then, he said.

“When I show how much overmatch we gain … it will have sold itself,” he said.

$700,000 sounds like a lot of money, until you put it on the scale against the cost of losing one lousy fight.

This entry was posted in Rifles and Carbines, Weapons Accessories, Weapons Education, Weapons Usage and Employment on by Hognose.

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

68 thoughts on “Marines Experiment with M27 IAR, Suppressor


Australia is starting its first large-scale foray into suppressing big-Army’s rifles and machine guns, starting in 2017. Getting them on the menu and not ‘aren’t they a SOCOMD thing?’ took a lot of staff effort.


What? Huh? Whatwazzat? Say again?

But seriously folks, this can only be a good thing. I had dinner with a friend at a crowded restaurant last night, and I spent 2 hours reading her lips, nodding politely and guessing what she was saying over the background noise. The primary reason for that is ten years regular exposure to unsuppressed live and blank small arms fire, often without earpro.

I once fired a blank round from my SLR at the same instant that my section commander flung himself to the ground next to the muzzle of my weapon. He rolled sideways clutching his head, and was deaf in his left ear for 24 hours. A bit of that action in your 20s will leave you half deaf in your 50s.

And there are the obvious tactical advantages that accrue from better comms within the section during a fight. As a section commander I could never get my guys to hear me over the noise of their weapons, and I’m a big guy with a really loud voice. At the same time, the enemy will have trouble locating you suppressed weapons…

I reckon thst the force that fields large numbers of suppressed weapons will have a decisive advantage over an unsuppressed enemy at the section and platoon level.


” I had dinner with a friend at a crowded restaurant last night, and I spent 2 hours reading her lips”

Australian restaurants are the noisiest in the world. Between the music to make waiters happy and the health department approved sanitary hard surfaces, they absolutely roar.

Hognose Post author

I imagine the first time to the rifle range, the reluctant officers will come away with a sense of the possibilities. Good on yer, Oz.

Clarence Chen

Now suppressors I can get behind, but I do think 3k for what is in essence a piston AR to be slightly to expensive for my feeble mind. But hey, if they get the data back and it says that the HK really is German Space-Magic than it’s a hell of a lot cheaper to win with more expensive weapons that lose with cheap ones.

Hognose Post author

I’ve had several auto industry execs tell me that it doesn’t cost materially more to make a $100k car than a $30k one. The bulk of the differential comes in the cost of selling the first as a $100k car. HK has been selling das Schlangenöl (although an actual German wouldn’t use that word, as their equiv of “snake oil” doesn’t use that metaphor) for fifty-plus years.

They sell these to the Marines, and every MP5 they provided to Golan and Globus in the 1980s has a 10,000% ROI.

Also, issuing every Jarhead one of these would probably come to ~$500M, which is probably less than the Corps spends on Sexual Harassment Introductory Training.


Oh, and one suppressor per barrel for support weapons like the Minimi/SAW/M249/Mk46 and the MAG/M250/MAG58. Can’t believe some people actually thought one suppressor across multiple barrels was a good idea! ‘They’ were surprised to find they get hot!

Changing drills to lock working parts to the rear between serials on the range helped with the cooling, too.

Hognose Post author

‘They’ were surprised to find they get hot!

Yeah, it seems like there’s an inverse relationship between lessons learned at platoon level and advancement to nosebleed levels sometimes.


Were I a Marine acquisitions guy, I would do an analysis of the free float rails on the COTS market. There are tons of options, including some that let you keep your FSB gas block. Such a solution would get you the increased accuracy much cheaper than buying new 416 uppers or complete IARs.


I would agree, the Block II M4A1 would work sufficiently and already lives neatly in FEDLOG. The different add-on piston systems are many and varied and would require extensive testing to take them from hobbyist shooters to Marine proof.

My guess though is that they’re hedging the HK piston has been wrung out a little more and will keep their weapons clean enough when suppressed.


Adavntage of the G36/HK416 gas system is that it is self regulating and needs no user input to adjust for shooting with or without silencer.

Another self adjusting option would be the AUG derived upper that Steyr has been developing. A mature system as well and not as heavy and simpler with less parts and lighter weight too afaik.

Heard some time ago that SOCOM is running a development for an integrally suppressed upper receiver that is supposed to be used always with the suppressor mounted. SURG or something like that it is called.

so many options.

Another would be keeping the internal piston design but adding a gas block with a simple three position switch for suppressed, unsuppressed, dirty/cold weather like the micro moa “govnah” adjustable gas blocks for example. with known cartridges and silencers and propper adjustments to the porting should reduce gas blowback to the face to a minimum.

so many options. and even COTS available nowadays. and the USMC should roll out the A5 spring & buffer. They paid for its development after all.


I think the SURG program was cancelled but it would take a specific operation requirement approach like that to wring the best out of the equipment.

Hognose Post author

Some of those, like Daniel Defense’s for example, are already in the system with NSNs.


I have a suppressor on a 308 bolt gun. After firing 4 or 5 rounds in a minute’s time, the heat from the suppressor causes enough mirage to be a problem with a bare suppressor, so I use one of those fabric insulated covers.

When I see pictures of suppressors on military M-16 type rifles, I don’t usually see covers. How are they dealing with suppressor induced mirage? Less of a problem with the smaller cartridge? Less of a problem with lower power optics? Rapid fire creates so much heat you’d rather have mirage than an overheated suppressor (or cover)?


I haven’t notice mirage as an issue with lower powered, or un-powered optics, although clearly it is still happening. You just don’t notice it without the high powered magnification. I see it after 3 round of 300WM on my Mk13, but have never noticed it with RDS, ACOGs, or LPVs on my other guns. Even though I let them get MUCH hotter.

Hognose Post author

Some of the SOPMOD suppressors ship with covers, but one hard fact of mil use is that small accessories get lost. The two-sheet design of the KAC suppressor, with one full of holes and both welded together, is supposedly meant to increase surface area exposed for heat management. (The KAC has widely been replaced by the Surefire). But the real reason is that most suppressed weapons that fire a lot are used with 1 power to 4 power optics, no more.


Using a piston based AR like the HK 416 does not make a difference for reduced fouling or gas-to-face if a suppressor is attached. Suppressors greatly increase the back pressure, and all the crud comes back into the receiver directly from the chamber.

The 10.4″ HK 416 is somewhat notorious for being a poor suppressor host, despite being paired with the Surefire RCs, which are arguably the lowest back pressure suppressors besides the terrible OSS cans.


True. Most of the dirt is blown back through the barrel and chamber. The only help would be increasing time between shot fired and unlocking. But that would require a seriously changed concert of gas system, port size, cam path of the bolt… etc. etc.

Makes you wonder if a truly new rifle designed from the ground up would make sense to go fully suppressed taking into account the changed variables. hmmm


I was under the impression that the piston weight degraded accuracy potential?

It is good to see the USMC has some leadership willing to experiment and not stuck holding Vichy victory parades for the F-35 Thunderpig.

When I was in mid 80s they experimented with the German squad make up/tactics or something like that, I was in arty we were experimenting with putting 198s under CH-53Es and losing them in 2000 feet of water.

Hognose Post author

The Canadians seem to have given up on the F-35 and ordered new gen F-18 Super Hornets (a whole different plane from the early CF-18 Hornet they’re flying now) instead.

2000 feet of water doesn’t seem like impossible to find and recover a howitzer. You can find it with MAD from patrol planes or helos, and pull it from a salvafe ship with a big-ass electromagnet. A thorough wash in fresh water, relube and oil, and it would probably be GTG, if recovered in less than a year or so.


Not so much when they drop into 200-ft. pine forests, and the howitzer barrels on guns so big and heavy nothing else can move them ashore can be used to shoot around corners afterwards.

But hey, the Corps is experimenting, great stuff.

To bad Lame-us Amos and ff. from Eighth and I have spent all the Corps’ cows on F-35 Thunderjug Magic Beans, and there’s no money left for anything else, like replacements for the 40 year old AAVs, or anything else.


My bad it was a 5 ton truck and an Echo off San Clemente and it was 2000 something or another. Rookie pilot overheated something or another spending a half hour or so trying to hook up and flew a few thousand feet from the ship when the Jesus Nut came loose and 3 men went with it. I believe the truck was the same weight as the 198. Had to correct myself.


It seems to me that HK’s system is very similar to LWRCI’s.

Why not buy an AMERICAN rifle designed and built by AMERICANs?

I’ve 2 LWRCIs and for quality, reliability and accuracy they can’t be beat… (free floated barrels too).


Hognose Post author

John, I dunno why the USMC chose HK > LWRC but they did. Here is the LWRC competitor.

Because some one is getting themselves set up for a high paying job as an HK shill after leaving the USMC.

The 416 is not really better than the BLOCK II M4.

FF and piston operated seem to be an oxymoron


I still say that while suppressors are a Really Good Thing ™, there are times and places that noise is not only an effective part of the weapon, but a necessary one.

I’ll grant that the benefits likely outweigh the negatives when it comes to the issue, but I will continue to maintain that there are huge psychological and morale effects which stem from the noise we make with weapons. It would be unwise to forget that, or ignore the ramifications.


I don’t disagree, the rip of an MG42 would serve to take the starch out of most folks. That sound is now replaced with the snap and crack of just the bullets wake from a suppressed weapons equipped fire element, none of the boom.

When they put a can on one of their 25mm, LAV cannons is what I want to see.


There’s also a psych and morale effect from not knowing where your enemy is… I would expect that effectively, suppressor use across entire units makes every rifleman an unseen “sniper” in the eyes of the enemy, or a sniper effect multiplied…

Raoul Duke

This is an interesting experiment, and much cheaper in the long run than pouring millions down “Joint Services” rathole “studies” that result in no equipment being fielded *cough* handgun *cough*.

For those getting a case of the vapors about blowing three grand per grunt for…gasp, something evil like a gun… do the math. How many less F-35’s does that equal? One? One-and-a-half?

Maybe DoD will have to cut down on diversity and LGBT celebration days just to afford rifles. It will be tough, but we all have to make sacrifices.


The only issue I have with what they are doing is that the testing they are doing leaves out a huge part of the equation-Namely, the enemy.

Sure, in some circumstances the silenced unit will have advantages; in others, the effect on enemy behavior will be unpredictable. Defeat is an event that takes place in the minds of your opponents; remove the cues that tell them they have lost dominance in the fire fight, and they may fight on, killing more of your men than they would have had they been convinced to withdraw by the noise of your volume of fire.

It is a nuanced thing, but the effects are real-And, significant. Leaving out live enemy actors during testing is a mistake, in my view. If the tests in stateside exercises indicate good things, they absolutely need to take another step and do operational tests against a variety of combatants before moving to force-wide fielding.

Hognose Post author

But there remain plenty of weapons that make noise on the enemy: from 40mm on up to the mighty 2,000 lb JDAM, which can be launched from a strategic bomber out of sight and sound of its target.

As far as suppression goes, it is extremely frustrating to be fired on from an unknown direction and source, which is a principal benefit of suppressed weapons. Not only the volume but the pitch of the sound is changed, and as anyone with field time knows instinctively, human sound-location abilities are highly pitch-limited. Shifting the register sound is in can make it dissipate over a shorter distance for the same given amplitude, as well as make it more difficult for listeners at various distances to pinpoint the sound.

Of course, it only offers the adopter a temporary advantage relative to his enemies. If the technological advance proves an advantage, the enemy too adopts it quite quickly.


You are a highly-trained and experienced professional soldier; you have few peers on the other side, and most of their mass of combatants will not respond to the situation created by a fully silenced small arms suite the way you would. Maybe “silent death” will be more effective and have unexpected psychological effects on the enemy. On the other hand, maybe the frustration of not knowing where the fire is coming from will drive them into entirely irrational behavior, and we will get higher losses on our side because of that.

I once observed a young light infantry LT do an intricate OPORD, one carefully planned and calculated to acheive a specific effect on the enemy. Should have worked perfectly, when it was executed. It didn’t, despite his guys doing everything to plan-And, what really ‘effed it all up? The OPFOR augmentees he was going up against just did not respond or react per the plan. The rational, smart move would have been for them to do “A”; they did “Q”, and accidentally won the engagement with a panic-stricken mass charge out of the kill zone that overran the majority of the ambush party and the oh-so-smart young LT. End of the day, he had 90% casualties, and the people he was targeting suffered about 30%. As the OPFOR O/C put it, “Don’t forget to tell the enemy, when you defeat him… He may not be smart enough to know how f**ked your perfect little plan has left him”.


That comes directly from Maxim 47:

“Don’t expect the enemy to cooperate in the creation of your dream engagement.”


I would imagine that suppressors do increase FLIR signatures?


The AAC cans that Socom has for the 46s and 48s are amazing. They greatly improve the ability to shoot while standing.

The 416 is such an over rated weapon, it amazes me.

Though I stand by my original comment that some one is getting ready for a high paying post USMC job as a HK shill. They speak about a AR with a piston on FF rail as if HK is the only ones doing it! Welcome to 10 years ago I guess,

On a side note, the USMC has been working with colt and Colt Canada for a while now about a new service rifle. Though I am sure the HK Old Boys Club is loathe to admit there are other systems being looked at.

My experience with the HKs ( 416 and 417) is less than impressing. I have a few friends whose agencies issue 416s and they claim the 416s break and break down when their Colt M4s do not. I think the only real value the 416s offer is an illusion of perfection and indestructibility for the user, Ignorance is bliss I have heard said…


In what ways do the 416 go down?

Hognose Post author

They kind of hammer themselves to pieces. Very violent action compared to other ARs.


I’m no HK fanboy, and the 416 is probably over-rated.

But did you follow the news from the IAR competition? Do you really suspect the USMC somehow rigged that competition so that HK would win?

At the beginning of the IAR competition, I didn’t expect the HK entry would win, as it was one of the lightest of all the entries. But it sure seemed to have won fair and square.


Doesn’t the 10.5″ 416 weigh about the same as 14.5″ m4 profile barrel, due to 416 needing heavier barrel to maintain similar levels of accuracy? m4a1/socom barrels and hk416 are probably pretty close in weight though…


I think this is overall a good thing. Yes, sometimes making noise helps your own side’s morale and hurts the enemies’ morale. However, I believe that killing the enemy more efficiently would help your side’s morale more, and hurt the enemies’ morale more. I’m not saying this from a theoretical standpoint; I have my CIB from repeat trips to Afghanistan and Iraq, with over 25 years in the Infantry.

I never had a suppressor on my M4, but I was in several TICs working with people who did. Yes, it was a significant advantage. It makes a tremendous difference when shooting in doors.

Remember the scene in Blackhawk Down when one Ranger gets deafened for the rest of the fight by another Ranger’s muzzle blast next? That shit is real. Loss of hearing in a fight can get you killed, and definitely raises the stakes for everyone on your team. How effectively can someone watch your back when he’s deaf?

The command and control improvement is going to be a big one. I’ve seen squad leaders have to get up and run through enemy fire to communicate with a team leader who was 20-40 yards away and couldn’t hear the squad leader. Yeah, the cool headsets and earpieces for the squad radios are a help, but when you are a yard away from a SAW gunner laying down some hate you still can’t hear diddly squat with the earpiece.

Dyspeptic Gunsmith

I’m always infuriated when I read articles such as this one.

We’re the most heavily armed nation on earth. We have more “gun nuts” per square mile than anywhere on earth. We have more people working on designing, making, building, testing, modifying, shooting, cleaning, destroying and collecting weapons than any other nation on earth.

So why the *(&*^ can we not buy something like the above-described weapon (or better) from a source here in the US? There’s nothing to recommend H&K as a government contractor – or a civilian arms supplier. When did we, the most heavily armed nation on earth, decide that we needed to send our tax dollars to a bunch of goof-offs, halfwits and grifters of the sort who made the G36, who live in nations populated by people who still believe in the supremacy of inbred cousins humping each other, whom they call “royalty?”

This sort of BS makes my blood boil.

That we’re talking of paying $3K (sans optics) for something I can buy in the commercial market for less than half that – now I’m at a nice, rolling, frothy boil.

On top of that, I notice that a General is still obsessed with the possibility of burning off “too much ammo.” The chairbound in weapons acquisition in the US military have had that obsession since the mid-19th century. It’s the reason why there’s a magazine cutoff on the 1903 Springfield, it’s the reason why the Garand was semi-automatic, it’s the reason for the three-round burst, and on and on and on and on and on.

How is it that all the opposition forces in Dirka-Dirka-Dirkastan aren’t worried about their AK’s being full rock-n-roll? How is it that the Dirka-Dirka-Dirkas always seem to have enough ammo, and yet they’re packing full-auto weapons?

I would never have made it in the military. When I see world-class stupidity like this, I’m incapable of keeping my mouth shut. I’m sure I would have spent most of my enlistment in a stockade somewhere…

John M.

You heard that Kaiser Bill’s throne came to a bad end, right?

-John M.

Dyspeptic Gunsmith

Yea, but when I talk to a European (and especially about the Second Amendment), their view of rights is still straight out of their mindset of reverence for their inbred, cousin-humping ‘royalty’ – ie, that their rights are ceded to them by their betters, not that their rights pre-exist the formation of a government.


sad but true. German constitution is written as being based off inalienable rights, but daily practice is still very much peasant to lordship. 🙁


“How is it that all the opposition forces in Dirka-Dirka-Dirkastan aren’t worried about their AK’s being full rock-n-roll? How is it that the Dirka-Dirka-Dirkas always seem to have enough ammo, and yet they’re packing full-auto weapons?”

Supply chain, for one? We’ve been fighting recently on others’ turf.

Despite that, I would also hazard that there are logistics issues on the other side, as well as vast differences in fire discipline, tactics, and deployment of resources.

That said, ammo conservation with a full-auto should not be an issue with a competent, well-trained 11x.



I have seen estimates of ammunition expenditures from more formal armed outfits in South West Asia. They are only estimates because of cultural biases against keeping track of and reporting such things accurately. Even still they seem to absolutely hemorrhage munitions in combat. That is when they are not loosing and/or diverting said material to the black market.

I see no reason to think irregulars from the same cultural background are any different. This opinion is reinforced by the prevalence of a “to whom it may concern” attitude about fires.

Then again I think defaulting to “more DAKA!” is a very human response. It can probably be trained around. But, the constant desire of western brass to limit ammo wasting though hardware solutions points to its existence as an issue.

As for insurgent ammo supplies, I assume that Muj just goes some place else when he runs dry. Hit and run is the order of the day for most of those guys. According to my reading of islamist propaganda, a jihadi gets “eternal credit” just for trying. Unlike coalition forces, an insurgent can either blend into the crowd in urban areas or flee and bunker down in some hidey hole when he is out in the boonies.


Ahhhh, great discussions guys. Pro or Con on the H&K, I give Thanks To USMC for taking action! I’m all for improving the combat capabilities of our forces in the field. If that means photon blasters, so be it. Several days ago I read another article about the new rifle being tested and immediately thought, “are they preparing to field suppressors?” Then this appeared.

Hognose made a astute oberservation “If the technological advance proves an advantage, the enemy too adopts it quite quickly.” I would add, he adapts because he has to for survival. His fellow comrade took a round in the forehead or a 1000 pounder in the gut….

This discussion is so refreshing and better than talking about the outgoing gov’t/DoD retards F-ing up our Armed Forces…. Thank you!


Hm, so this makes it seem like the Marine IAR program really WAS a backdoor attempt to buy a better assault rifle after all, rather than a true automatic rifle, as some suspected at the time. Either that or a fortuitous coincidence. Clearly a good thing overall, especially in how the Marines seem to be testing things properly. But it’s still a shame the Marines aren’t investigating Jim Sullivan’s MGX design, with its amazing controllability on full-auto.

Hognose Post author

I haven’t shot (or even seen) the MGX, but the Ultimax, also his design, was an eye-opener.

Steve M.

So why hasn’t the Ultimax been given greater consideration or has it? It has always seemed like the way to go, but I am just a civvy gun nut with very little FA and no MG experience.

Hognose Post author

NIH Syndrome, and it didn’t keep pace with advancing (i.e., resolving to AR-15, which had it mostly right all along) ergonomics.

Steve M.

Thanks for the reply. I was only thinking of mechanical function not the aspect of an IAR actually having the same ergonomics as the basic weapon every Marine should be familiar with. I failed to consider that. Similar ergonomics makes sense to me.


Hognose, you’ve probably already seen this, but others may not have. I too have never even seen a real-life picture (rather than a patent drawing) of a Sullivan MGX, but he also makes the same basic operating system as an AR-15 retrofit. Back in 2014, Ian of Forgotten Weapons interviewed Sullivan, and fired one of his AR-15 prototypes on video:

We can’t see the target, but the apparent controllability while Ian fires Sullivan’s AR-15 in full-auto, including ONE-HANDED with the stock NOT touching his shoulder at all (!) looks amazing. I am surprised that Sullivan’s Ultimax-style Constant Recoil concept works that well within the much more limited space of an AR-15 upper receiver, but it sure seems to.


When you think about fouling and internal gun temps, a piston design makes sense for an IAR. When you think about shared ergos/manual of arms/etc, an AR15 piston makes sense…

What seems to be the case is that getting additional small arms approved when the Pentagon powers that be are focused on caseless ammo, next gen guns, etc, that using an existing approved small arm in a new role was deemed to be much easier than procurement process from scratch for a new role… Satisficing if you will.

Jim Scrummy

As per usual great discussion in regards to the M27. Not to change the topic or hijack the thread, but when I found this last night I fell out of my seat reading it.

Here’s the link to the pdf:

I am trying to decide if this is an Eff U or capitulation by DoD?

Interesting times.

Hognose Post author

I’m writing about this for (I hope) tomorrow. BLUF, it’s Bob Work and the other Obama appointees’ pre-emptive strike against concealed carry on base. It sets up a bunch of “Jim Crow Literacy Tests” that look like they permit something but really forbid it, when you read closely.

Jim Scrummy

Okay. I did want your take on it and others. Sorry for jumping the gun.


Maybe I’m just reading it wrong but it looks like it’s basically the same rules we had to follow for carrying an issued weapon on-duty. No alcohol or drugs 8hrs prior to duty, if you’re under disciplinary review you’re on the SWAT team (seeds, weeds and trash) until the commander clears you back on the arming roster.

Of course it’s still very much a “may issue” rule. Each installation commander has always had the authority to run his post/base/yard as he saw fit; example would be back in the 80s when they kept on base drinking age at 18 until they got leaned on from higher. So, my bias may be showing from my SP heritage in seeing pretty much the same rules. I’m very curious to see your take on it and see what I’ve missed.


Flyboys get the F-35, Navy gets a Zumwalt or they have been Zumwalted and Marine grunts get a can, yeah life’s fair.

Hognose Post author

Well, Zumwalt was last seen dead in the water in Panama….


I have some knowledge of the original Marine Corps Infantry Automatic Rifle competition. Everyone loved the Ultimax, but it was designed for teeny Singaporeans. On a full size American wearing body armor the sights simply would not index. And the Corps had, rightly in my opinion, specified an off-the-shelf purchase. As far as the H&K whinging from all the “range experts” here, you need to understand what a Marine Gunner is. He’s a former (successful) infantry platoon sergeant turned warrant officer who has gone through the Infantry Officer Course and every other weapons employment school there is. He is an infantry battalion commander/regimental commander’s personal advisor on weapons training and employment. He’s a terminal warrant officer who takes no shit off anyone. Weapons and tactics don’t happen unless that community checks off on it, and if they check off on it, it’s the right way to go. They were the ones who decided that the SAW was not working in combat in the context of fire team fire and movement and urban warfare. They’re still looking for a reliable high-cap magazine for the IAR, despite how great YOUR C-MAG works on the range.


Indeed. Gunners have a unique place in the Marine infantry ecology. The ones I served with were outstanding, true masters of their trade.

For those with access to jarhead propaganda, AKA the Marine Corps Gazette, Gunner (CWO5) Eby was a driving force on acquiring a true automatic rifle and has several articles in their archives on the subject.


Could the so-called “linear brake” blast diffuser serve as a cheaper yet practical alternative for a suppressor to achieve some of the desired goals of the suppressor experiment? Perhaps using the “linear brake” on the full-auto support weapons?

It seems to me a muzzle device which drives more noise from your support weapons downrange towards the enemy and also less noise towards your flanks and rear could only be a good thing.


Flash signature is much increased over A2 flashhider. Only real advantage is indoors. A flash hider with a detachable “blast shield” for indoor use would be an interesting and much cheaper combo to experiment with however… IIRC, someone makes a blast shield that does fit standard A2 flash hiders.


Correct me if I’m wrong, but aren’t we going to need a lot more SDO/RMRs if the Marine Corps goes to an IAR in every pot, due to barrel length and BDC on RCOs?


Not really. The difference in bullet drop is not that much and Trijicon services older ACOGs and could put a different reticle in while they are at it.


They say the old is new again. Blow up that image at the top and it looks to me a lot like an MP-44/STG-44 inside.