US Army’s New Magazine A FAILURE? USMC Test of Enhanced Performance Magazine Shows It Performed Worse Than Predecessor, PMAG

The EPM (left) alongside the older tan, green, and black follower 30 round USGI magazines.

The US Army’s newest magazine for the M16 and M4, the Enhanced Performance Magazine (EPM), failed a recent USMC test of rifle magazines, according to a recent Marine Corps SYSCOM document released by National Review. The report shows the EPM coming in last in the tests, with a mean rounds between failures (MRBF) figure below the baseline 600 in almost every subtest. In contrast, the magazine from Vendor A – which TFB has confirmed was the Magpul PMag Gen M3, recently adopted by the United States Marine Corps – was the best performer in every subtest. You can see the results of the test in the slides embedded below:

It should be noted that although these tests do not reflect well on the EPM, there are some potential mitigating factors to be aware of. First, it is evidently that at least some of the rifles and carbines tested had some performance issues unrelated to the magazines themselves. At least three of the weapons experienced light primer strikes, at least one weapon had problems with its trigger not resetting, and several weapons experienced stuck cases – all malfunctions that have nothing to do with the magazines themselves. Having said that, even adjusted for these malfunctions, the PMag still performed the best out of all the magazines tested.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • Joshua

    Light primer strikes and failures to eject/extract have nothing to do with the magazine.

    • USMC03Vet

      Washington Times…. The same group that create no author listed clickbait gun photo slide shows that are hilariously bad? Leave it to the experts!!

  • it’s just Boris

    See? They should have gone with GLOCK!

    (Sorry, couldn’t resist…)

  • Turd Sterling

    The US Armed Forces bean counters. Over complicating things for centuries.

  • 40mmCattleDog

    Ive been wary of the military “tests” ever since the 2007 dust test was drastically skewed to make the M4 look unreliable. How they listed light strikes and failure to extract as magazine issues doesnt make sense.

    • James Kachman

      I concur with your skepticism, especially since inter-branch politics may be at play.

    • TechnoTriticale

      re: …test was drastically skewed to make…

      I read a lot of alleged science papers, and it’s an artless investigator indeed who can’t design a trial that “proves” exactly what the sponsor wants proved.

      These mags may actually have a problem, but that needs to be verified with rifles that at least pretend to be reliable.

    • neckbone

      I wouldn’t trust anything we are told from a gov agency or dept. Sad it’s come to that

    • Major Tom

      Military “tests” have also been rigged and set up to do the reverse: Make the M16/M4 seem reliable compared to any competitor.

      • crackedlenses

        Which ones?

      • CommonSense23

        Please name one.

      • Samuel Millwright

        Considering the ordnance department hated it from day one and did everything possible to sabotage the initial tests that got it bought, but that didn’t work so they heavily borked the production decisions for key components and the ammo situation too…. Ya know, just to make sure it wasn’t so good SPIW would get cancelled!

        They’ve then run multiple other programs trying to replace it as often as possible…

        And in the last decade which has seen the commercial guns thoroughly ironed out and perfected, they’ve chosen to actually adopt basically none of the thoroughly proven improvements….

        But we’re supposed to believe they cheat to make it look better when they’ve spent 5 decades trying to kill it?

      • cawpin

        The M16 and M4 ARE reliable, so I’m not sure what skewing would happen.

  • Joshua

    I also want to point this out.

    I was never a Marine, but I’ve been a part of these types of tests before.

    The Marine corps used M4s for this, if you know anything about the M14/M16 burst cam you know any time you have a stoppage mid burst the cam does not reset.

    So if you fire one round and it stops, the next pull of the trigger will only fire 2.

    Even though it’s just a design function of the cam, in Government testing….especially big Army testing I’ve been in that is often classified as a failure to reset for the trigger and labeled a stoppage.

    It’s not a stoppage and it’s not a trigger reset issue, it’s strictly a design of the burst cam not resetting backing to 1 mid burst.

    Now I don’t know if that’s the case here, but historically it has been so take that into consideration on all the trigger reset failure.

    • James Kachman

      Would explain 23 of the failures, I suppose. Their failure to segregate the M4 and M4A1 results is obnoxious.

    • int19h

      Wow. That is insane.

      • Joshua

        The burst cam was a crap design the Marines came up with.

        Unlike HKs burst cam that always resets to 1 no matter what ours does not.

        If you fire 2 rounds and then the bolt locks back empty, well the next time you chamber a round your only going to fire one shot.

        It goes against everything a burst fire trigger should do, and it’s always counted a stoppage.

        The burst FCG for the AR was literally the most jankey, bubbad design ever imagined.

        • int19h

          Yep, I’m familiar with that sad story. But the fact that this by-design behavior actually counts as a stoppage in testing, but is not blamed on the design, is completely and utterly insane.

          • Joshua

            Yeah, I’m not actually sure why they count them that way.

            It’s just ” a burst trigger should fire 3 rounds on one pull of the trigger” if it doesn’t do that, its a failure….except not really, and I’ve had arguments with guys about this who score these things.

        • FWIW: The M16A2’s burst cam was based on Colt’s own patented designs from the 1960s. Major Dave Lutz, the M16A1E1’s project manager, pushed the 3rd burst as a compromise option to prevent the complete elimination of the select fire feature.

          • Joshua

            I still blame the Marines for the abomination that is the M16A2.

          • Fair enough, as it was the USMC’s project.

            I still believe that Lutz misread the ARL’s data for establishing the stock length. He somehow interpreted the ideal stock for the 95th Percentile data as fitting 95% of the male soldiers. No, you just made it too long for 94% of the users.

            In addition, Colt’s staff basically had field day selling the USMC on all of their shelved improvement projects from the 1960s.

          • cwolf

            ARI at USAIS highlighted the long stock issue. It was raised to the TRADOC level. USAIS response:”We don’t care if short Soldiers can’t shoot it.”

            Then we started using IBA (which was not used in testing).


          • iksnilol

            Wouldn’t the “best” stock be ideal for the 50th percentile?

          • I’ve seen it suggested that it is easier to cope with a stock that is too short than a stock that is too long. Stock length also needs to take into account the thickness of clothing, armor, and webbing.

          • iksnilol

            Oh definitely, I’ve used cut down rifles intended for children without much of a problem (and I’m tall). So, I can see how that is true. But adjusstable is probably the best solution.

          • Adjustable stocks were long feared as being too fragile. In the M16 family, you had the added complication of matching the carbine buffer’s weight to the rifle-length gas system. It took forever for the H6 buffer and adjustable stock to be approved for use with the M16A4.

          • iksnilol

            I’ve never understood the complex thingamajigs of the AR buffer system. As far as I understand, the adjustable buffer tube is shorter?

          • Since the adjustable stock’s buffer tube is shorter, the carbine buffer has to be shorter as well.

          • iksnilol

            Obviously… I’m just baffled by how many different options there are for AR buffer systems is all.

    • Bal256

      The remarks don’t even implicate that. It blames the M4 failures on things like light primer strikes. Now the mag getting knocked out of the magwell might be an issue for the M16a4. Not sure if it means the magazine or the mag-well itself is out of spec, but since the EPM was designed specifically for the M855A1 and specifically for the M4, I wouldn’t be surprised if they just didn’t take it into account. PMAG still king.

  • RSG

    What is PE MRBEFF?

    • James Kachman

      MRBEFF = Mean Round Between Essential Function Failure, dunno about PE.

      • RSG

        Excellent. Thx for taking time out of your busy day to take on the task that should’ve been defined by the author of this article.

        • James Kachman

          Fwiw it’s not defined in the report itself either, and MRBF (from which MRBEFF is derived) is a fairly standard piece of jargon.

          • RSG

            Except for those that missed Statistics 101 for Dummies, there isn’t any context. Of course, there was a simple remedy……….

      • Joshua

        Which is interesting.

        MRBEFF is generally reserved for Class III Stoppages.

        In this case they are using Class III stoppage terminology and applying it to Class I/II Stoppages which are MRBS.

  • NewMan

    M27 Is clearly the best performer and this has been proven time and time again.

    Sad that they’re still desperately clinging onto the M4. Politics as usual.

    • Joshua


      Yeah those results don’t show what you think they show.

      • NewMan

        You’re a funny guy bro… Data clearly showed the M27 stomped the competition. Can’t wait to see how u gonna do damage control for the failed and outdated M4

        • Joshua

          The M27 didn’t really stomp the competition if you understand how these work.

          80% of the failures listed were trigger reset failures on the M16A4/M4 which both use a non resetting burst cam.

          It’s a design function that the government has always listed as a stoppage when it’s not.

    • J.T.

      Of course it performed the best, they made sure it did. They used M4s and M16s with obvious mechanical issues and counted those problems against the magazines. we also don’t know if they used the same guns to test each combonation, and if they did, what order it was done in and what type of maintenance was done to keep the guns running during the test. It hardly sounds like it was done scientifically.

      I’m also suspicious as to how the M27 didn’t have any issues when using the legacy mags and M855A1, since that combination is know to cause reliability and durability issues.

      • NewMan

        LMFAO did you even see they say M4A1 in the chart?

        Let’s pretend even if what you’re saying is remotely true, this data still debunked the author previous claim that the M27 perform poorly with the M855A1.

        It’s hilarious watching DI M4 fanboys doing damage control.

        • James Kachman

          They reported trigger reset issues, which means it’s an M4 using that kludge of a burst mechanism. (Thanks USMC!)

          And it’s not the author’s claim that the M27 chokes with M855A1, it’s the USMC’s claim. That’s why they adopted the PMag in the first place, is to fix the feeding issues of EPR in the M27.

          Further, the M27 suffers from durability issues with M855A1, namely chamber pitting and shorter bolt life. This was less than 5k rounds fired on rifles which I assure you were either new or not far from. They wouldn’t see (and didn’t measure) wear in that short of a round count.

          • NewMan

            Nice try. There’s no proof whatsoever that M27 has durability issue with M855A1, other than the author “anonymous source” with zero data to back up that claim lololol.

            All attempt to smear the M27 has failed. It is here to stay and continue to beat the competition. Get used to it.

          • James Kachman


            Brig. Gen. Shrader: “So, sir, General Walsh is referring to the testing that we’ve been doing with the Army on the EPR round, which is their advanced round, which is the M855A1 round. That’s the one we’ve heard a lot about the Marine Corps and the Army having working toward. The testing that we’re doing is that round has had some durability – it causes some durability issues for our new Infantry Automatic Rifle that we fielded, the M27.”

          • NewMan

            That merely ONE general opinion with ZERO data. All the latest test showed M27 perform extremely well, like this one. Try again.

          • James Kachman

            I provided my source, I’d be interested to see yours. An actual durability test, mind, not a magazine test where the users don’t know how the burst setting works.

          • Uniform223

            “I provided my source, I’d be interested to see yours”

            > all of his trophies playing Call of Duty counts for his experience and knowledge in firearms.

          • AC97

            His source is “Ermahgerd, I’m an HK fanboy”.

            That’s it.

          • Joshua

            I posted an update.

            The M16s and M4s were old the M27s we’re new to monitor wear and tear from M855A1.

            The point of the test was never to compare the M27 to the M16/M4 so they didn’t bother getting new M4s.

            It was solely a magazine reliability test and M27 wear test.

          • James Kachman

            I saw, thanks. I am somewhat pleasantly surprised that the M27 did so well, if only so that it does well until replaced by an M4A2 of some form.

          • Joshua

            You sure about that?

            Don’t worry everyone, broken chamber walls are by design.


            And that’s just what I can share.

          • NewMan

            Cute propaganda picture from AR15 com forum with ZERO source.


          • Joshua

            Yeah I just whipped that up in Photoshop, even added the chamber damage myself.

            I’m a wizard at Photoshop.

          • Nick D

            What Mfg. EPM mags did they use?

          • Joshua

            Center industries. They’re the only ones making them atm.

          • Nick D

            Have you heard anything about Okay Industries getting in on mfg. or submitting mags for the new 855A1 ammo.

        • Joshua

          The Marine Corps uses the M4.

          They did not hop on the Army’s recent M4A1 contract and have no desire to procure M4A1s.

        • Bart Jabroni


    • 40mmCattleDog

      Ah vintage newman. Anything to scream PISTONZZ RULE right? I forgot your the guy on the internet who knows more than all of USSOCOM about what works in combat and that you think they are all stupid for going for a DI Block III carbine.

    • Uniform223

      You should change your name to “SlowMan”

    • Samuel Millwright

      No, it’s not…

      It’s also absolutely STUPID expensive… And plain stupid

  • Aaron

    I would have to ask how many of these failures would have been mitigated by improved weapon maintenance on the part of the armoury? Things like new trigger springs and bolt replacement parts. If anything this clearly shows the adage “correlation =/= causation.”

    • Duane Liptak

      All weapons used in endurance tests start as new, and all inspection and replacements happen at TM intervals. Lubrication and cleaning is dictated by TOP 03-02-045

  • yodamiles

    Just like I said before, US military is stupid for not adopting Glock mag……

    • Anonymoose

      Stupid for not adopting the G36/XM8 mag. Heck, we have lowers now that take AK mags, so why not one that takes a super-reliable constant-curve 5.56 mag? (other than cost, since Magpul makes G36 Pmags)

      • James Kachman

        Because that’d require replacing every M16/M4 and every magazine in the inventory for something of marginal benefit, as well as killing off what’s left of STANAG commonality.

        • iksnilol

          What STANAG commonality?

          Everybody runs their own anyways.

          • PK

            “It’s the principle of it!” is the usual answer I hear. You’re 100% right, though… when has magazine sharing been an issue, in modern times?

          • James Kachman

            No, it really doesn’t matter, which is what I implied by “what’s left of.”

            The cost to replace all weapons and magazines is a bigger deal, and why it won’t happen.

          • PK

            True! Luckily it’s good enough for now.

          • James Kachman

            Setting aside the Stoner/AR koolaid (which I *love*) the failure to make a curved mag well is one of the few real failings of the design.

          • int19h

            Is that still true, actually? UK, Canada, France, Belgium, Norway, the Netherlands, Italy, and Czechia now all use STANAG mags in standard-issue firearms. In addition to these, allied non-NATO countries doing the same include Sweden, Israel, South Korea and Japan.

      • Bart Jabroni

        You’re very dumb.

        • Anonymoose

          no u. One of the main reasons the XM8 performed so well in tests was because of the constant-curve G36 mag it used. Too bad it had that overheating problem. STANAG mags suck.

  • Old Tofu

    why are the images links back to this same article?? one would think that if you clicked on them you would get to a larger image , like the rest of the internet works

    • PK

      “Firearms, not back-end performance.”

    • You have to right click and open in new tab.

      I am not sure why it does this. It’s a WordPress thing, so far as I can tell.

      • Mystick

        I am not impressed with the performance of WordPress lately. You would almost be better off DIY in Dreamweaver.

  • Dingus

    I have mostly green follower mags, and I don’t have much trouble out of them. I prefer aluminum or steel mags to plastic, as I have seen p-mag feed lips falter, when subjected to a bit of heat.

  • Shaun Connery Oliver II

    Dag! I LOVE the SUREFEED mags! There has to be political tom foolery going on around here!

  • Sticky-eye Rivers

    BREAKING NEWS: US Marine Corps find US Army equipment “the worst evar”, insist USMC get extraneous funding for new, unique equipment

    “an’ tha no ones but us gets too have itsss…my precioussssss”, more BREAKING NEWS at 11.

  • Kinetics

    “Fighting” the EPM really doesn’t seem to be working; they’ve already authorized individual units and Marines to buy M3’s with unit and personal money and the M3 is the only new mag the USMC has authorized for combat.

    Why not just go the final step and do a true service-wide adoption of the PMAG M3?

    Is there really that much opposition to officially stating that *this* particular polymer magazine is better than anything else?

    • Dr. Longfellow Buchenrad

      I dont think fighting with the EPM would work all that well either.

      Regardless the data clearly states what everyone already knew: PMag is best.

    • James Kachman

      ‘Why not just go the final step and do a true service-wide adoption of the PMAG M3?”

      Because the Army and the DoD don’t own the technical data package for the PMag. They want to have their own design that they can produce with all the methods and modifications that their little hearts desire.

      Is that worth the hassle? You tell me. But there’s a reason for them doing it.

      • Kinetics

        Ah gotcha, hadn’t thought about that but it’s the Crye/Multicam issue all over again but with a different service and object obviously.

        • James Kachman

          Yeah, and it’s ending up the same way. The Army’s EPM “borrows” a lot from the PMag.

          • Duane Liptak

            There’s a series of test data after a 2011 PMAG test where Picatinny changed the presentation angle of the USGI to closely resemble the PMAG M3/EMAG presentation. It’s pretty blatant that they were trying to capture what the PMAG does in the most “flattering” way possible. But they missed all the other things that have to change in order to really see any benefit.

          • James Kachman

            Thanks for the specific citation, I was just reiterating what I heard from Bartocci.

          • int19h

            Can Mattis just tell them to shove an EPM up their ass and adopt PMAG, because he said so?

    • Gun Fu Guru

      Because plastic degrades over time. Magazine bodies from the 80s are still in use.

  • Dr. Longfellow Buchenrad

    Photos with all definite non-magazine failures edited out. The MRBF numbers still arent accurate though. The data simply isnt detailed enough to get correct numbers, but these should at least still be better.

    You would think in a magazine test they would bother to distinguish between stuck cases and bolt over base failures… but I guess this is the government we are dealing with.

    • Joshua

      Now that’s some fancy phot shop work.

    • Flounder

      Excellent work sir!

      I would like to take note of that first comment on the epm… Why do they say all malfunctions happened on the first day? Did someone forget the lube until the second day? How many days were there? It is driving me crazy. Because with your numbers that could make it roughly equal to the others if something was purposely bungled on the first day. Which happens often enough with new equipment.

  • Corwin Bos

    Too bad they dont test Lancers. For durability, the Lancers beat MagPuls offerings easily due to steel feed lips.

    • James Kachman

      The Lancer uses a standard follower, which presents rounds at a shallower angle compared to PMags. Great for most rounds, but the M855A1 has a steel penetrator tip which will gouge the feed ramps when fed at that angle. PMags and the new USGI EPM (which stole it from the PMag) have a higher angle which presents the M855A1 round much better, reducing feed wear. It’s why the USMC adopted the PMag.

      • Corwin Bos

        I didnt know that. However, it would be very easy for Lancer to just use a slightly different feed lip on the mag without need to change anything else. The follower isnt what present the bullets in an AR mag, the feed lip angle geometry is what controls feed presentation.

        And the M855A1, all smoke and mirrors baloney brought to you by the same clowns that designed the Army’s camouflage….

        • James Kachman

          Apologies wrt feed lip angle, my memory is faulty. You’re right that it wouldn’t be a difficult change, and I’d be eager to see it happen.

          Honestly, though, I’m a strong advocate for M855A1. The only remaining doubt I have is its cost, because I haven’t seen anything solid on it. Everything else looks to be far better than M855, though I’d advocate putting a LPB treatment on the M4 bolt to help it be even more amazing.

          • Corwin Bos

            As a devout reloader I look at the bullet construction and powder charges they are using, and its bad news. They are running extremely hot, in the danger zone, over pressure rounds, to get the velocities they are getting. That in turn will simply wear guns out, DI or piston, doesnt matter.

            And you are absolutely correct about cost. You want an accurate assessment of cost per round? Compare a solid copper Barnes bullet vs a traditional projectile. They are generally about double the cost. They are also using copper for construction which is a far more rare element than lead is. The bull___t about “green” ammo is exactly what it sounds like, bull___t. War isnt green. They claim penetration is the primary reason, but they can easily design a bullet with a steel tip, with a lead core, and just a copper jacket over the entire thing, which would be cheaper, likely more accurate to boot. Speaking of accuracy, they getting 2-3″ groups at 100 yards from well built, accurate rifles, not the beat up crap that most of servicemen and women carry.

            All in all, its a piss poor design.

        • Duane Liptak

          You can’t just change feed lip angle on the magazine. That’s what the EPM tried to do. Everything else has to work with that steeper angle, or it’s a train wreck, as Picatinny found out.

          • Corwin Bos

            Yes, but that is where you start, followed with a slight redesign on the follower if needed to match the angle of the new feed lip geometry. In the Lancer mags it just happens to be easier to change these things without having to create an entirely new mold for the mag body. This is because its just a piece of steel that is secured to the mag body.

          • Duane Liptak

            It’s a lot more than that. You can’t just change the follower, too. The EPM was a change to angle and then to follower. Feed lip change to solve one problem introduces another problem. Follower attempts to fix it with a band aid. Everyone is welcome to give it a shot. Except for the stuff that’s locked down in IP, of course.

    • Duane Liptak

      Actually they don’t beat PMAGs in the rough handling tests, and if you ask more questions about who vendor B was, you’ll have your answer.

      • Corwin Bos

        Ive seen way more Pmags, old or new design, split down the spine, and feed lips being worn, than I have on any Lancers. Plastic breaks off under stress, steel bends but can be straightened.

        Magazine life span is an issue. Plastic < Steel. Pmag feed lips do wear out. Ive worn some out and they started causing weird failure to feed issues. I trashed the ones that were trash, and the rest sit on a shelf in my office. They were replaced with Lancers 20 rnd mags and I switched back to GI mags for my 30 rnd mags. My buddy is starting to experience that on his as Pmags as well.

        • Duane Liptak

          At what round count? There are GEN 1s and 2s with 30-60k on them, but even the older materials aren’t anywhere near what the M3 does. Bent metal lips cause stoppages–USGI or anyone else’s–and they all bend. If a PMAG holds rounds long enough to get into the magwell, it will feed. Bent feed lips generally don’t. And the job of a magazine is to feed and work in real environments. They’re class IX consumables, but you’ve got a 10 year history of the PMAG success in combat with probably close to 3 Million in combat service–and even with the old materials, durability has not been a concern in combat usage, regardless if that goes against your personal experience from whatever sample size you are speaking from. The fact that they run, always, is. You are more than welcome to prefer whatever mag or other product that you want. But just understand what you are truly giving up by doing so.

          • Corwin Bos

            Mine were having issues with feeding high, as up into the gas tube. Round count was about 5k on a couple of them They are 1st gen mags.

            They may be considered a consumable, but you can bet your ass the Marines expect you to turn in your mags. Doesnt matter if you were in combat or state side the entire time. This is a USMC attitude, if its issued, they expect it back. I served during Gulf War, so I know how it really works.

            The other reason I run Lancers? They feed 300 BO and 458 SOCOM better than a Pmag will ever dream of with any weird combinations of bullets Ive tried. And to be honest, Im giving up nothing. For my use, they are superior in every way.

          • Bart Jabroni

            The boss laying down the data again!

      • Joshua

        You realize this report shouldn’t have been released to the public right?

        • Duane Liptak

          Joshua, it was released via a FOIA to one of the constituents of a Senator looking into the magazine issue. Yes…that probably shouldn’t have happened. Good or bad, though, it was released. Not by us…we never had it until it was already public…and we still didn’t publish it.

          • Joshua

            I didn’t think y’all did. But hey, I’m hoping this coming to light will force the Army to do what’s right.

            This test proves that you can take M4s kept in poor maintenance, slap a Pmag in them and reduce Stoppages to nearly zero.

            It’s what I’ve been telling the powers that be in PEO for a while….they’re just so dead set on making their own.

            But I hope this make them see it just doesn’t work.

            I’ve seen Pmags do magical things to guns that constantly have feeding issues.

        • Duane Liptak

          Joshua, this was released via a FOIA to a constituent of one of the Senators looking into this magazine issue. Not by any of the involved parties.

      • Nick D

        Who was Vendor B, you should know since you were Vendor A???

        • Duane Liptak

          I absolutely know who vendor B was, and it’s common knowledge for relevant military activities who have received the full report, but that information was not released via the FOIA that got these results slides onto the street. It’s not hard to guess, but 100% confirmation should come from an official source to keep everything on the up and up.

  • Joshua

    Here’s something else i was thinking about.

    Where did the national review get these slides.

    Their .PDF solely consists of only these three slides. One thing I’ve learned is the government loves their PowerPoints, and they love their distribution notices.

    This has neither, why doesn’t it have a distribution notice?

    I’m beginning to question the validity enough that I’ve sent inquirys into a few of my friends about this.

    On top of that, this test doesn’t even close to matching prior tests done with Mk318 on legacy magazines…in which case practically every gun tested achieved over 950 MRBS and the M27 never came close to 4800.

    I’ll update ya’ll when I hear back from my friends.

    • Joshua

      So heard back from some people.

      The data is legit, but leaked…shouldn’t happened but it did.

      Anyways it was not a M27 vs M4 test, it was strictly to prove the Pmag is a superior magazine.

      Because of this the M4s and M16s used(and yes no M4A1 was used) were old and beat up.

      The majority of the non magazine failures were due to a combination of how the burst trigger is counted(like I said) and the light primer strikes were just because the guns were old and in need of replacing parts.

      So there you have it. New M4s and M16s would still have had the trigger reset problem, but the primer strikes were on old guns.

      With the M27s being newer stock to verify the Pmag feed M855A1 properly and to gauge damage(which required a new gun with no prior use, we all know well what to expect from the M4/M16 thanks to army testing).

      It was strictly to show Pmags reign supreme in the magazine department, and to gauge how the Pmag negated damage to the M27 vs the other magazines in the test.

      • LGM Commando 070

        Using old and beat up rifles for such a test makes no sense.

        You are a salesman, Joshua. Pushing the product. HK outperformed M4 and that is clear.

        • Flounder

          LOL, I love the sarcasm. But your comment reminds me of the dust test the army did a few years back. They had eight or so brand new guns, then went out and just pulled a couple of m4s out of the armory. Then did a reliability/sand test. Of course the m4s placed dead last with double the malfunctions. And when colt got pissed and demanded they used brand new m4s they did. And it was shown the m4 was equal to all the others.

          I believe it was early 2000s and it was primarily a sand test. The hk was there with the 416? i can’t remember, I think they also had the XM8 there, the scar was there for sure and did very well. And I seem to remember at least one other rifle. Maybe two. And I think there were multiple rifles from each manufacturer. Hopefully someone can help me out with the source.

          • Joshua


            XM8, SCAR, 416s and M4s pulled from an arms room.

            It was funny because when the serial numbers were ran, Colt had delivered those M4s, 7 months prior to the testing date.

            It’s also worth mentioning they again had the burst cam.

            That means every stoppage is guaranteed to be counted as two, due to the way the S-1-3 FCG works.

            I will also say Colt did later send 10 brand new M4s to STARK…now called something else since they were bought out.

            At the time they were one of the highest rated government testing sites around.

            Colt told them to duplicate the dust test and came out with around 110 Stoppages.

          • LGM Commando 070

            If the purpose was to use old rifles to test new mags then how could it be determined what caused the malfunctions?

            If the purpose of a new rifle in the test was to compare the performance of the mags then it had to be the same kind of rifle.

            This is called reasoning.

          • Joshua

            The test was not to prove one rifle is better than the other.

            The test was to prove Pmags were superior, by using old worn out rifles they proved that you could go from 150MRBS with EPM mags, to 900+ with Pmags.

            Basically saying this magazine is soooo good, that it can take a worn out rifle and make it run like a beast again.

            It’s the perfect way to prove a magazine far surpasses anything currently in inventory.

            Trust me the M27s were new. The M16A4’s and M4’s used were out of an arms room and were used and far from new.

        • Joshua

          I don’t get paid enough to be a salesman.

          Sorry your to dumb and biased to understand how the government does these types of tests….then again one would have to be American…and in an area of the DoD where they can know these things.

          You proved with your inability to get the M4A1/416 TRS that your nothing of the sort.

          • LGM Commando 070

            You are calling me dumb and biased and at the same time accusing me of poking and insulting people into leaking some documents?

            I refuted all the ridiculous claims of Joshua by sheer logic and he is tripping.

          • Joshua

            No, you never refuted anything.

            You just kept poking and prodding me to post proof of my claims of the maintenance schedules by posting the TRS for the weapons. Technical manuals that are not available for the public.

            So yes you challenged me to prove my claim by posting documents I cannot.

          • LGM Commando 072

            Poking, prodding? You are tripping, man.

            I said that BS was the claim that HK maintenace is “PITYFUL”, compared to M4 and I’m sure it is


          • Joshua

            The 416 receiver life is a fraction of the M4A1s.

            If you ever get DoD clearance I’ll send you the TRS for both rifles and you can compare them yourself.

        • Brett baker

          You do realize it’s 2017, not 1967, right? HK is still running on it’s 60’s and 70’s gear’s reputation to a large degree.

      • int19h

        From your personal experience, would you say that Marines are justified in pushing PMAG over EPM? As in, they may be cheating to make it look more convincing, but would you still prefer it to win?

        • Joshua

          I’m almost certain they chose used M4s for this test to help push pmgs over EPM.

          However the Pmag M3 is easily a far superior magazine to the EPM as well.

          There have been I think 4 tests done that prove the Pmag is the best magazine on the market, and this was another good way to prove it.

          Take older rifles and say look! Even on these older worn out rifles the Pmag is so good it can make them go 15+ standard combat loads without failure!

          • Nick D

            You are a wealth of great information Josh, thanks for all the insight honest feedback. Takes a while to filter through the nonsense on here.

      • Smedley54

        What?! The Marine Corps has new anything?! That they’ll actually issue?!

        • Joshua

          Not sure I understand?

          • Smedley54

            When I was in the Marines, new gear was hoarded in the armory and never used. Times have changed, but it sounds like the gear they were testing with is exactly the stuff we would have been issued.

          • Kent San

            They just kept it from the ‘tards back then. Sorry.

          • Smedley54

            Right – which is why nobody got the new stuff.

  • Brett baker

    Magpul triumphant, except according to the army.

    • Joshua

      The Army has begun running a test of their own.

  • EzGoingKev

    I have not read all 54 comments so sorry if this was already said but I would love to have seen a GI magazine fit with a Magpul follower thrown in there for comparison purposes.

  • 22winmag

    No wonder they are for sale cheap on GB.

  • Bart Jabroni

    And we’re supposed to trust that they made the right choice with the mhs as well.

  • Audie Bakerson

    Wonder who vendor b is.

    • Bart Jabroni


      • Audie Bakerson


  • Raoul

    Fake news.

  • Gun Fu Guru

    As I have said from the beginning, the problem is not the magazines. It’s the M855A1.

    • Samuel Millwright

      Riiiiggghhttt because the magazine hasn’t been the AR’s weakspot from day one or anything!

      It’s that god damn new fangled ammonishin!

      • Gun Fu Guru

        The initial magazines worked great with the initial weapon using the initial ammunition. By changing just one component of that triad, the other two have issues. Many people think that it doesn’t matter, but it needs extensive R&D to determine what changes, if any, need to take place with the other two.

        In this case, we created the second generation (green follower) magazine in 1985 to work correctly with the M16A2 and M855. When the M4 came around, they didn’t need to change the magazine at all since they extended the feed lips and changed the buffer weight. During the GWOT, we experienced rounds not moving up inside the magazine so Picatinny Arsenal created the third generation magazine (tan follower) to add an anti-tilt factor without any input from Colt. When the M855A1 round came out, it was 1/16″ longer than M855 and it smashed into the upper receiver around the barrel extension with it’s tungsten tip. (See picture below.) The military created the EPM (tan body, blue follower) to fix that issue by tilting the round upwards.

        The EPM works perfectly well. Look at the data in the tables above. It has an abnormally high Type #1 malfunction in the three weapon systems tested when using M855A1. It is well within two standard deviations (a commonly accepted statistical definition of “normality”) using MK318MOD0. It’s actually a top performer when it comes to the M16A4. Even in this test, there was still a light amount of bullet impact on the upper receiver if you look at the other slides. That dame was present with every magazine except the EPM (which was specifically made for that reason).

        If anything can really be gleaned from the data, it is that we should use the M27 with the legacy magazines that we already have in stock.

        Don’t get me wrong: the M855A1 round is the most superior 5.56x45mm cartridge available for military use. But that doesn’t mean that we have the weapons to effectively fire it. (It’s similar to the criticism I have with Heckler and Koch Mk23: it works perfectly but who wants it?)

        And don’t get me wrong again: the PMAG is the best magazine in the market. I never implied otherwise. It’s all I use.

        • Not such a guru, I guess, since M855A1 doesn’t have a tungsten tip. Its tip is steel.

          • Gun Fu Guru

            Not such a guru, I guess
            #1. Do you talk to people like a pompous sod when you are in-person?
            #2. My name on here is purely satirical and is aimed at all of the people online who claim expertise when they are far from being experts.

            since M855A1 doesn’t have a tungsten tip. Its tip is steel.
            You are right about the tip. I was was wrong. I read half of an article about the development of the round. It started off with tungsten, but that idea was scrapped in the mid 2000s.

            “Also, M855A1 has the same OAL as M855 does, if it were 1/16″ longer it wouldn’t even be able to fit in a QBZ-95 or Six8 mag, let alone a USGI.”
            I referenced the length of the actual projectile, not that of the cartridge. Because lead is more dense than steel and most other metals, the military had to add more metal to make the M855A1 weigh the same as M855. The trade off was that the projectile was longer and had to be seated deeper in the casing. While I was right about this, it didn’t have anything to do with the round hitting the upper receiver.

            The things you mentioned don’t impact the criticism I levied against the article you wrote. The title—”US Army’s New Magazine A FAILURE? USMC Test of Enhanced Performance Magazine Shows It Performed Worse Than Predecessor, PMAG”—was clickbait. The test didn’t show that the EPM “performed worse than predecessor.” The EPM didn’t fall “below the baseline [of] 600 [MRBF] in almost every subtest.” It only performed subpar in three of the six tests (remember, one test was 600). To me, that’s a far cry than “almost every.”

            Even then, you said in your last paragraph that “there are some potential mitigating factors to be aware of.” You correctly pointed out that “the PMag still performed the best out of all the magazines tested” after adjusting the total failures. However, you ought to have known that most people would have jumped at criticizing the magazine because they didn’t read the article. You pulled the same stunt using data from Andrew Tuohy to say that “FIREClean is Crisco.” (I have never bought or used the product.) Tuohy never said any such thing. He stated: “FireClean is probably a modern unsaturated vegetable oil virtually the same as many oils used for cooking.” The word “probably” definitely changes the context. He even called out the BS you spewed. A few days later, you and/or TFB changed the title to FireClean is Vegetable Oil.”

            Please raise your reporting standards. They are far below par.






    • Joshua

      Lol, M855A1 is fine.

      The AR magazine has always had a subpar feed angle and bullet presentation.

      Magpul fixed that.

      • Gun Fu Guru

        Funny. It worked fine in the beginning.

        • Joshua

          Yes, because Eugene Stoner designed the 20 round GI mag to be disposable.

          You unbox them, fire them, and dump them.

          They worked fine as 20 rounders but the issue comes into play with the 30 round curve they have now.

          • Gun Fu Guru

            Even the 30 rounders worked well with the original configuration of the rifle.

          • int19h

            They did? Then why did they keep changing the followers so many times?

          • Gun Fu Guru

            There are three parts to any weapon platform: the gun, the feeding system, the ammunition. There is a lot of R&D that goes into making sure that those three parts work well with each other. When one changes a part of that triad, it typically (but not always) creates issues with the other parts.

            We started off with twenty rounders and black followers. The military wanted a thirty round magazine, and they engineered one that worked pretty flawlessly without creating problems for the other two parts of the system (black follower). When we adopted the M16A2 and M885, we updated the magazines to the work well with the new platform (green follower). This combination worked without a lot of complaints from 1985 until the 2003 invasion of Iraq. In that conflict, we found that environmental conditions were causing the follower to tilt inside the magazine and which created a feeding issue. We created the anti-tilt follower which worked flawlessly (blue follower). This only lasted a few years, however, because we switched the ammunition from M855 to M855A1. The new round smashed into the upper receiver causing damage to the aluminum portion of the feed ramp. We had to engineer the tan Enhanced Performance Magazine to angle the M855A1 upwards to prevent this damage (tan follower).

  • Mr. Katt

    Well just darn, we’ll have to spend another $300 million to figure the magazine problem out. (DODTHINK)

  • Corwin Bos

    The reason they are now seeing improved barrel life? Very simple, it doesnt have the velocity of the M855. Velocity creates heat is what kills barrels. The initial spec paperwork I seen smelled like horse___t, and from someone that has a really good knowledge of ballistics, it simply was not possible. A long for weight bullet
    that increases chamber pressure that they claimed could go just as fast as the old one. So what they have now is a round that actually goes slower than the old M855 which in turn reduces overall effective range and lethality. There are a ton of variables at play and I could write a couple 1000 words on how all the variables play together but in the interest of time, I will not. I would like to see the final specs for FPS, powder charge and powder type.

    The price cant really be lower. Let just throw this out as an example. Lets say they are paying 10 cents a round for M855 which is a very simple design. I can guarantee you that M855A1 is 20 cents as it is not a simple process to create this bullet and the materials are for more expensive. More expensive to manufacture and more expensive raw materials.

    I totally understand we expend more ammo in training. I was in the Marines. These “factors” that demand ranges be kept lead free are all bullcrap, as most of us know. A bullet that is fired into a berm is inert, and very little to no lead from the round actually goes anywhere. Your car or truck produces more pollution on a yearly basis. Now if they are banging steel all the time and the bullet fragments, yeah, then you might have a problem, but last I checked the armed forces dont train on steel with any regularity.

    More lethal I will agree on. These bullets are not design for expansion. They are design to tumble and penetrate. However, this same design criteria could have been used in creating a better round without full use of copper as the base. A round that uses the same tip and a lead base, with a copper jacket would be just as lethal, if not more because lead expands far more readily at lower velocities. The added upside of using lead is that it is far heavier than copper which means they could have used a shorter projectile to hit 62gr with the same velocity of M855 , or lengthened to a longer projectile at 69gr which is more effective overall with the same terminal performance.

    M855 is a 4 MOA round because what most of our servicemen and women carry is made by the lowest bidder. From my personal rifle it shoots about 1.5 MOA, and my rifle regularly shoots at .5 MOA or less with my handloads. And you are dang right, I think our service members need better equipment. The millitary can piss away billions a year on stupid ass projects, but cant outfit the guy or gal on the ground with something that does it job better. We need an upgrade path, not an outright replacement. Dumping money into H&Ks isnt the right path, but a quality 8 twist barrel, a strong but light FF rail, would go a long ways in getting them up to speed using the remainder of the rifle as a jump off point. Thats the beauty of the AR platform, it can be made into whatever you want, the military can do the same.

    • James Kachman

      “The reason they are now seeing improved barrel life? Very simple, it doesnt have the velocity of the M855.”

      Huh? You realize that contradicts literally every other piece of published information, right? And the actual experience of people who’ve shot other people with EPR…

      I’m not claiming that EPR is cheaper than M855, nor was that a goal of the program. Mk262 is 4x the price of M855, which was one of the reasons they couldn’t whole-hog adopt Mk262. The goal was to keep it low enough to be able to replace M855, which I haven’t seen any evidence that they’ve failed to do.

      “These “factors” that demand ranges be kept lead free are all bullcrap, as most of us know.”

      That doesn’t change the fact that Army ranges *do* get closed because of lead going into the eco-system. Like, sure, mock the greenies all you want, but the Army had to put up with their crap, and used the money to fund a better round.

      If you put lead in your design to make it more lethal, congrats, the program has failed, you get no money, US troops don’t get a new round.

      Anyway, we agree more than we disagree, so the points verge on becoming moot.

      • Corwin Bos

        To decrease the chamber pressure there are a couple things to can do. Load less powder, which in turn lowers velocity. You can try slower burning powders, but in a shorter gas length M4 this create drastically higher port pressures which increases wear on the gas tubes, bolts and slightly on barrels. So what did they do to maintain the velocity? Magic? Or Bullshit?

        The initial spec of the M855A1 was 28.1gr of WC844 behind what is essentially a very long for weight projectile. The M855 is 26.1gr of WC844. The A1 claimed 3150fps with a chamber pressure of 55k psi. The M855 is 3025fps with 55k psi. I can tell you from first hand experience that the A1’s load is really really hot. The truth of it was the A1 was closer to 62k+psi and this is why it was tearing guns up. This math has been verified many times using Quikload software and comparing very similar loadings from elsewhere. What they are trying to do and what they are actually getting are 2 different things. Someone is feeding someone a line of BS. I dont buy it as the physics of it, it simply does not add up.

        • James Kachman

          They changed the burn rates between M855 and EPR to match the 14.5″ barrel of the M4, rather than the 20″ barrel of the M16. Powder types can improve in 20+ years. Do you have an actual source for lower velocities of M855A1, or merely conjecture?

          • Joshua

            The 14.5″ M4A1 is pushing M855A1 at 2,920fps…or around there, with a SMP-842 powder charge of 25.5grains.

            One thing to know is SMP-842 has a very specific powder burn rate designed for the 14.5″ carbine gas system of the M4A1.

            It was powder purpose designed for the Stoner gas system.

          • James Kachman

            I believe you, but is there a public source on the 5 cpr increase? That’d help convert a lot of naysayers.

          • Joshua

            It’s coming but it has a link so it has to be approved.

        • ostiariusalpha

          As shown by the problems the M27 piston is having with M855A1, it does have higher port pressure. Nonetheless, the longer gas system of the M4 seems to be handling this quite adequately.

        • Joshua

          WC-844 has never been loaded in M855A1.

          It uses a purpose created powder labeled SMP-842.

  • Joe Moore

    What was vendor B?

    • Joshua

      I cannot say, technically this report never should have come out but it is what it is.

      • neckbone

        So it’s out. Now you can say.

  • ties

    the military industrial complex is so corrupted it can’t function…. all bribes and softmoney,,,stuff gets passed because is will pad some ones pocket with American tax dollars….

  • Tom Currie

    Like it or not, for most government tests, the summary of results is generally known before the test is conducted — that makes it easier to know what results are needed.

    While the above is not quite 100% true, it does come close. Most government tests are designed and conducted to confirm the results that someone wants to have.

    Here we have the USMC conducting some obviously flawed “testing” to compare the Army’s newly adopted “enhanced” magazine against the Corps’ newly adopted COTS magazine, with the other two standard magazines used by both services tossed in to make the comparison look more complete. Did anyone doubt that the Corps would find that THEIR new magazine was better than the Army’s new magazine?

  • Bon

    Lancers ftw but ill take pmags as well or gi mags with pmag followers.

  • McThag

    Is the “legacy” magazine the tan follower or green follower magazine?

    Vendor A is clearly the Magpul and the PMAG.

    Who is Vendor B? What model magazine? I hate when they get all cryptic about it.

  • USMC03Vet

    ARMY = Ain’t Ready to be Marines Yet.
    Apparently that also applies to their magazines. 🤣

    • majorrod

      LOL, we were saying something similar when you adopted M4’s…

  • Travis

    Just standardize PMags and be done with it. SMH

  • Mystick

    Another government bloat program to fix something that’s not broken.

  • ToddB

    How long has the army had to come up with a reliable M-16 magazine? Over 50 years. Im not sure the issue, I have metal mags I brought home from the marines and I got out in 1992, they still work fine.

    • majorrod

      Er, you do realize those mags were the same the Army was issuing and may even have come from an Army buy the Marines jumped in on…

      • ToddB

        And? Why would it matter who bought them? I have a mix of mags, various makes of old surplus, new metal ones, all various brands, can’t say one is more reliable than another. Its the idea that after 50 friggin years, they keep trying to ‘fix’ the magazines. HK can seem to make them work fine. PMAG seems to get it right.

        • majorrod

          Doesn’t make a difference who bought them. I mistakenly thought that was your point.

          Unless you are shooting several thousands of rounds a year out of dozens of mags from different lots (and marking all your mags) I doubt the number of mags you have and the amount you shoot is a scientifically significant sample size.

          I would use “improve” vs. “fix” when it comes to mags. No doubt newer iterations of AR15/M16/M4 mags do better. HK mags work in HK’s. Seems to be a proprietary thing there.

          PMAGs are great. I also like having more than one source for magazines especially when it comes to war.

  • Klaus Von Schmitto

    I’ve always wondered why Marines need a full auto M16? Every time they pull the trigger they kill someone right? A whole platoon of Marines should be able to kill 51X30 opponents without changing their magazine.

  • Bal256

    Everyone is attributing motive, when all it is is raw data clearly explains itself that the failures were due to light primer strikes and the like. What’s the alternative? “we did a test, but the failures were nothing to worry about so we’re not going to publish the data”. Clickbait headline.

  • victor victor bravo

    Finally a scam that results in superior equipment.

  • Blue Centurion

    Who was Vendor “B”?

  • Kodi

    The inherent bureaucratic jungle that now encompasses almost every buying decision Big Army makes is unlikely to produce successes going forward.
    While not perfect, the smaller & more $$$ conscious USMC generally makes better decisions in the long term. Consolidating purchases for all services under one omnibus contract isn’t always good for any individual service, often forcing all to make unnecessary compromises that don’t fit their budgets and missions.

    • majorrod

      “While not perfect, the smaller & more $$$ conscious USMC generally makes better decisions in the long term.”


      The Osprey, CH53, M27, F35C would prove the opposite…

      Toss in the late adoption of the M4…

      You may want to reconsider that “better decisions” propaganda. Now I would agree that the Corps marketing and branding overwhelmingly sets the standard for other services. Anything endorsed by the Marines is going to be automatically going to be considered the best especially by those that don’t know much about the specific product or potential competitiors.

  • majorrod


    “Having said that, even adjusted for these malfunctions, the PMag still
    performed the best out of all the magazines tested.” Did they use the
    SAME malfunctioning guns on ALL the mags? If you use the malfunctioning guns on only a portion of the sample you have further skewed results.

    I’d be skeptical about the test given the Marine Corps’ very strong and often incorrectly based resistance to M855A1. The results seem very self-serving.

  • gregge

    Why wouldn’t they use new rifles or rifles that had been checked over for proper function and repaired as needed?

  • Kent San

    Yes it failed to beat the Magpul, but enought to overcome the procurement preference given to small and disadvantaged transexual midget Eskimos businesses? That’s a high bar.

  • Magpul PMag Gen M3, recently adopted by the United States Marine Corps – was the best performer in every subtest. You can see the results of the test in the slides embedded below:

  • Hyok Kim

    Thanks for the useful report. This issue is especially critical for civilian SD. Far less likely to have a back up and far more likely ECQB than the USMC.