Taking a Closer Look At the Differences Between the ACR and the MSBS

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Since the announcement that Fabryka Broni is seeking to import the MSBS modular rifle into the United States civilian market, there has been a great deal of discussion about the relationship of the MSBS to the Remington ACR or Magpul Masada. The two rifles are very similar, similar enough that I’ve previously referred to the MSBS as a “Masada derivative”, but I wanted to take a closer look. Therefore, at the 2016 SHOT Show, I took a look inside both rifles, to compare their similarities and contrast their differences. I found that, while there are conspicuous similarities that previously led me to believe the MSBS is a Masada derivative, there are also a great deal of subtle differences that suggest more convergent development based on similar requirements and design philosophy – and likely cross-pollination of a few ideas –  than the Fabryka Broni team picking up where Magpul left off.

Let’s explore what I’m talking about. First, the takedown of the two rifles is different, with the ACR having a similar takedown to an AR-15, with the upper receiver hinging open with the buttstock attached to the lower receiver (it differs from the AR-15 in that a single pushpin is what locks the buttstock to the lower):

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The red arrow at top points to the takedown pin of the ACR. Push that pin out from left to right, and the gun shotguns open like an AR-15. The blue arrow at bottom points to the stock removal pin. It’s not necessary to push out this pin to disassemble the ACR.

 

The MSBS, however, uses a different takedown system, more similar to a G36 than an AR-15:

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On the MSBS, the buttstock and upper are held together by the slot in the buttstock frame. To field-strip the MSBS, fold the buttstock, push the large textured button inside the stock housing, and slide the stock off of the rifle. It will then hinge open like an AR-15.

 

Once both rifles are field-stripped, out pop two very similar looking bolt groups. In detail, however, there are some significant differences between them:

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Both use Stoner-type multilug rotary bolts, with roughly hexagonal cross-section bolt carriers with forward assist notches cut in the front, but while the ACR has a fixed (removable with effort) guide rod and spring assembly, the MSBS has one that falls right out of the carrier. Unlike the ACR, the MSBS has a cam pin located in the 12 o’clock position when the bolt is fully extended, not the 3 o’clock. One can also see that while the ACR’s bolt carrier is milled from a single piece of steel, the MSBS has a carrier made from two pieces welded together. Presumably, this is to facilitate some complex shape inside of the carrier that could not be achieved by machining from one piece.

Taking a look at the bolt faces of the two rifles, we can see that versus the ACR the MSBS has one fewer lug (also like a G36), as well:

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From the views above, one can see just how similar the cross-sections of the two bolt carriers are. Both use a rectangular cross section with a sort of Aztec pyramid profile on top. One more thing that is very evident from these photos is how compressed from top to bottom the MSBS’s operating group is versus the ACR’s. This is a major reason that the MSBS is lighter and looks more svelte than the ACR, as the top to bottom volume of the receiver is significantly less.

The MSBS also features two Allen screws in the rear of the bolt carrier, although I am not sure what they are there for:

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Visible in this shot is the very small-diameter firing pin of the MSBS. In contrast, the ACR uses a unit very similar to an AR-15’s.

One of the advantages the MSBS has vs. the ACR in terms of reliability is substantial underlug, or travel before the bolt makes its unlocking turn. This delays extraction of the case, allowing the case walls to contract again and ensures smoother extraction and functioning. To facilitate this, the MSBS has a much longer – and therefore heavier – bolt.

The MSBS and ACR sport different methods of barrel retention. The ACR has the famous “ratchet” quick change barrel device:

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While the MSBS uses a simpler and lighter locking screw:

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Notably, both use “half length” upper receivers, which are monolithic to support a full-length rail and shield the operating mechanism, but feature separate 3, 6, and 9 o’clock rails. Note the MSBS’s heavier fluted barrel profile, as well as the lack of an additional gas piston support around the barrel. The folks at Fabryka Broni were very proud that they were able to eliminate that extra element. Also notice the placement of the charging handle, very similar to the original Masada. Like the ACR, the MSBS uses a push pin to retain the handguard.

A final similarity to take note of: Both the ACR and MSBS use AR-15-derived modular (trigger pack type) fire control groups, however the MSBS rifles at the show were select-fire units, and featured what I believe is a very simple and effective style of full auto sear:

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The yoke-shaped block in the front of the trigger group is – I think – the auto sear. If the bolt hit this block upon its frontmost travel, it could conceivably depress the sear and fire the weapon fully automatically.

 

There are many similarities between the MSBS and the Masada/ACR that I did not cover here (including the construction of the upper and lower receivers, and much of the basic architecture). Having taken a closer look, I don’t feel like I can say to what extent the MSBS team was influenced by the Masada. What is most interesting about these observations to me, however, is that possibly the G36 was an influence on the MSBS’s design team. It would make sense, as the G36 has become one of the most influential rifles in European small arms design in the 21st Century, with both the FN SCAR and CZ Bren 805 taking many cues from it.



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 can be reached via email at nathaniel.f@staff.thefirearmblog.com.


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  • Sam

    I want one.

    And military contracts aside, it baffles me that the SCAR has gained so much popularity over the ACR. The SCAR is huge and clunky and seems to be a few steps behind the ACR is design, ergonomics, and looks.

    I hope this thing gets approved and we can get quite a few companies making accessories… which is the only thing that’s kept me from buying an ACR.

    • Anonymoose

      I think a major point of contention is the ACR’s lack of factory and aftermarket support, and poor quality control on the early rifles. The ACR definitely has a better stock, which is why they make adapters to put ACR stocks on SCARs, but the SCAR also has a lot of its promised caliber/barrel conversions, extended handguards, replacement grips, etc, available (for a boutique price, perhaps, but at least they can be had), unlike the ACR.

      • Sam

        Exactly. And most of that is a result of the SCAR being picked up by some SF units in the military. People want what the military carries and companies create accessories/aftermarket stuff for that market.

        Remington made a huge mistake by promising all sorts of barrels, but never delivered. And the original rifle was made by the leader in tactical rifle accessories… and there’s next to nothing for it. Color me confused, because the ACR blows the SCAR out of the water.

        • GearHeadTony

          The SCAR is popular because it’s chambered in 7.62×51. (The SCAR light is nowhere near as popular) If there were an ACR heavy it might be a different story.

          • mechamaster

            Actually they have the 7,62x51mm version called Magpul Massoud.

          • GearHeadTony

            I dare you to find an article about the Massoud dated after 2011. That rifle was dead in the water years ago.

          • Cuvie

            The designer of the Massoud now works at the Kinetic Research Group which is developing a similar rifle called the FOX-42. This very website has posted a couple of articles about it

          • GearHeadTony

            Nice…as long as they don’t sell it to Bushmaster.

          • Kivaari

            Isn’t the current Bushmaster actually Remington?

          • GearHeadTony

            Bushmaster got the rights for the purpose of selling single-fire only models to civilians. Remington got the rights to sell select-fire models only to LE-MIL.

          • J Galt

            Don’t worry we won’t sell it to Bushmaster 🙂

        • BrandonAKsALot

          ” And the original rifle was made by the leader in tactical rifle accessories”

          Spend some time coming up with a design you love for something. Put your blood, sweat, and tears into it and make it something you truly love. Now sell that design to a company who only cares about profit. They’ll change the design and do away with all your frivolous little details, because they cost more and take too much time. It might not be as good, but it’s probably good enough and if there’s an issue; they’ll fix it when there are enough complaints.

        • John

          When people think of a SCAR, they think of the SCAR-17. It’s a modern FAL with AR-15 compatible furniture and ergonomics. As a battle rifle, everyone loves it.

          Many people have forgotten about the SCAR-16, on the other hand. The AR-15 has been described as “Barbie for men” due to the huge aftermarket support and accessories it has. The SCAR-16 is a plastic version of an AR, with half the aftermarket accessories, for twice the price. It’s not a good deal

          • Robert Harper

            Some people have made an ACR stock adaptor for the FAL, I’ll be doing a modern FAL build with VLTOR fore end, Railed gas block and lower so nice BUIS can be installed, and an ERGO grip, give it a good finish job and polish the trigger. It’ll be nice and since I have a “few” FAL mags, spare parts, (not that they’ll be needed, I’ve never had to replace anything on one of my FALs), and most of the parts I need for the build I’ll have a very nice modern FAL for a much cheaper price than a SCAR 17.

      • mosinman

        i think it has to do with logistics. FN seems to have more support and manufacturing dedicated to the SCAR when compared to Remington and the ACR

        • Green Hell

          FN is a major military industrial corporation (largest in Europe, actually), with a rich history of iconic firearms and military contracts all over the world. Of course it’s products would be preferable to a gun designed by barely a garage buisness like Magpul.

    • BrandonAKsALot

      The SCAR has it’s flaws for sure. The trigger is horrendous for a $2k+ gun, the safety detent is so over sprung you need a crowbar to move it sometimes, and all the rails that aren’t readily removable/modular. You’re also comparing two guns with a decade in between designs, so the SCAR does show it’s age in a few respects like not having modularity in the rails.

      You really have to consider the SCAR is made by a very old and successful arms manufacturer with top notch production methods. You’re getting some of the most durable and high quality barrels produced in the guns and a finely tune operating system that works well. I wouldn’t call it huge or clunky in any way, but that can be subjective. The forend could be longer and a little smaller, but I find it very comfortable and light. Even the 17 is light. The ACR does have a bit more streamlined appearance.

      The ACR is a really fantastic idea, but there are a lot of unknowns and cons in many senses. It was designed by an accessory company and sold to another company that cares about bottom line #1. It had lots of hiccups in early production like the low quality barrels, issues with the ratcheting barrel system, and bad disconnectors that caused multiple shots per trigger pull. Then continually delayed production, piss poor support, little to no aftermarket, and a totally botched start. I was absolutely dead set on getting one. I fell in love with it when I saw it on future weapons and waited years for it. It was very upsetting to see it all go that way. It was doomed once Magpul let it go. If they would have at least kept rights and had it produced, it could have gone very differently.

      • Sam

        I love FN. They make an amazing product. I’d buy a SCAR 17 if I could do something similar to a build, rather than buy the entire rifle and have to replace the lower receiver to accept SR-25 mags, the buttstock, handguard, and trigger. The stock gun just doesn’t do it for me the way the ACR did when I first handled it.

        Everything you said is spot on.

    • NewMan

      Because the SCAR is actually a reliable gun.

    • Do this guy’s videos help explain why? https://youtu.be/fL0-bQA5iw8

      • tb556

        ^ guy is not very bright, just sayin’.

        • I mean, I don’t disagree that buying an ACR is a dumb move, but you’re being a little hard on him, aren’t you?

          • tb556

            Not really. He can’t seem to perform the basic aspects of root cause analysis.

      • Kelly Jackson

        He seems like one of those goobers that likes to shoot 1000 rounds out of a rifle until it catches on fire, not really proving anything either

      • Kivaari

        I wonder why this video was posted in the first place. It seems like he has no clue. Nice looking gun, with good looking optics. By the way has anyone received the refund from EOTech?

        • If you watch the additional videos on his channel, it’s clear the guy had nothing but trouble from the ACR.

          But, I mean, lemons happen. It’s just that when the ACR is a lemon, it’s a fat, inaccurate lemon.

    • Also, I am given to understand that the military ACRs were very expensive.

      • Kelly Jackson

        wow

        • Yep, and even if we adjust for barrel profiles (the SCAR 16 has a profile similar to the M16, while the ACR has an M4-profile barrel), that only would add about 0.2 kg to the SCAR, or subtract 0.2 kg from the ACR. So architecturally, the SCAR is still 0.352 kg (0.776 lbs) lighter. That may be being generous to the ACR, too, since the SCAR 16S’s barrel profile is fatter under the handguards than a real A1.

          • jono102

            I have experience with both the SCAR L and H but none with the ACR, from a military perspective balance has to be tied into the weight equation. How that rifle balances out 3 days into a dismounted patrol will largely contribute to what I think of the weight. As an example over 2 deployments in a dismounted role (5-7 days self sufficient) I preferred my Steyr/M-203 incl a bomb up the spout to a standard Steyr. It just sat nicely in the patrol position with the increased front end weight.
            Not saying the ACR is good or bad or the SCAR for that matter, but out side a range or a carbine class, operationally balance is very much a large part of the weight consideration. The MSBS design seems to have cut a lot of unnecessary mass that the ACR appears to have

          • Yep, balance is key. One of these days, I am going to create a rifle balance omnibus.

            The SCAR has nothing on an AR-15 (or even an FAL) for balance.

          • jono102

            Don’t mention FAL’s, I sold my L1A1 last year. It went to a better home though as it was spending to much time in the safe. It was a nice to carry and the balance made the overall length less noticable

          • Robert Harper

            Then this will make you feel worse, I have 3 ACR stock adaptors for the FAL coming to me next month! 🙂 A few people have done them before and they work very well, I have one rifle for one to go on right away, and will be building an “updated” FAL with VLTOR fore end, railed gas block so a nice set of BUIS can be installed, and the ACR stock. The third adaptor will just be nice to hang onto until I decide to do another “FrankenFAL” build. 🙂

          • As an FAL purist… Ewwww. 😉

          • Robert Harper

            LOL, I can understand that, that’s why I’m not doing it to one of the nice FALs I have. Plus I’m building a pristine matching number Argentinian kit on a matching number Coonan receiver this weekend to absolve myself! 😛

          • jono102

            Kind of regretting the sale, I already have my eyes on a shorty Para FAL that looks pretty nice. Now if I can justify it and use the bloody thing once and a while, I may be back in there

          • Robert Harper

            Justification: It’s the Right Arm of the Free World!!! As far as using it goes, yeah, I haven’t found a decent range around me but since I just got a .22lr kit for my FALs I’ll take it to the pistol range and freak some people out. They look WAY too big to be a .22!

          • Robert Harper

            You can always justify it! They’re one of the hardest to kill rifles I’ve seen, google search The Tale of Old Dirty, it’ll make you cringe a bit as I’ve seen insurgents take care of their weapons better, but it does show you the kind of abuse a FAL can handle! I’ll be putting together a nice minty, all matching Argy parts kit with custom numbered receiver today. I figure that should absolve me for my upcoming tactical FAL build!

  • mikewest007

    From what I’ve heard, MSBS has some feature that allows you to switch the shell ejection from right to left with minimal tools, but the photos disprove the specifics I’ve heard. However, the two hex screws in the rear may hold the answer instead.

    • Philip

      Yes, it’ll be able to switch the shell ejection. Check out more vids about MSBS on youtube.

    • jono102

      Its apparently achieve by taking the bolt out rotating it 180 degrees and placing it back in. The only tool required is for the ejection port cover held by allen screws. The rifle will function with out the cover but will assist with keeping crap out. A lot technically simpler than the ARX 100/160 system. There’s a lot of vids around of the bull pup being fired from both shoulders do not a massive use as with other bullpups

  • Philip

    Hey don’t forget about bullpup version of MSBS. I hope it will be on the civil market too.

    • ostiariusalpha

      Even if they don’t sell the bullpup as a standalone unit anytime soon, you could still buy the standard model and get an adapter kit later. The MSBS rifle’s modular receiver can be changed back and forth between the two layouts.

  • kzrkp

    Is there a better picture of the MSBS barrel change? there’s a wedge in there somewhere.

    • Hokum

      I think there’s just that screw which you remove and the barrel goes forward.

      • Yeah, there may be a tensioning mechanism inside that trunnion, but to remove the barrel, they demonstrated just unthreading the screw and off it comes.

        • Kivaari

          Is there a serious reason why a rifle needs a quick change barrel?
          I don’t see any military needing that feature. It nice when a barrel is worn out, but that’s with every thing. For the cost of doing a barrel change on the M16, it should just be a total upper group that gets swapped out. The time it takes for an armorer to pull it apart then rebuild it, costs more than a simple swap.
          Hobby shooters like the novelty of doing it. Beyond that is seems like a waste of time. If I want another caliber, I buy another rifle.

          • Makes cleaning easier? Or if your Jim Sullivan, because you want every single rifleman to be a SAW gunner. 🙂

          • Kivaari

            Well, cleaning would be easier. I don’t think making everyone a SAW gunner is a good idea.

          • jono102

            That’s what cracks me up. In general it isn’t a biggie for the military. Even with our Steyr with a detachable barrel, where most teachings in a field/operational environment are not to remove the barrel for daily maintenance where ever possible. To the point the new EF-88/F90 Steyr barrel isn’t as easily removed, which will fix the ugly Unload/show clear drill the Aussies have.
            Back in a base camp/firm base it would be nice but not essential to be able to remove the barrel to get under the hand guard and huck it out the crap that can collect under there if the hand guard is not easily removable. I think its a case of the civilian market wanting something the military market doesn’t deem necessary or a requirement.

  • Joshua

    I like how the carrier is broke and welded back together.

    • westerly1

      They’re made in two pieces and welded together. It’s just how they manufacture them. It’s right in the article.

      • tb556

        Polish Engineering…

      • Joshua

        I’m not sure that’s praise worthy.

        One should not have to cut the carrier apart and weld it together. That’s poor engineering.

        • westerly1

          I never praised it I explained that it wasn’t broken.

    • Just Sayin’

      ATF made them chop it in order to get it in the country for the SHOT show, they had a local fab shop weld it back together.

      (BTW, I made that up just in case anyone was wondering)

  • Kelly Jackson

    I’d rather see more info about the bullpup version

    • BattleshipGrey

      I would as well, but the standard version is reportedly coming to the US first and it’d be a little strange comparing the ACR to the MSBS bullpup. Nathaniel dispelled myths about this new system at no cost to us.

  • tb556

    I’m predicting that no one on the internet will be interested because it will be “too heavy”

    • Kelly Jackson

      And not an AR15
      People on the internet love to complain they don’t get these cool rifles from overseas but still buy AR15s

      • Green Hell

        All I can really think of are HK guns (G-36 and MP-7 on the top) and modern Russian stuff like counter-balanced AK-107. Pretty much everything else worth having is already available in US.

        • tb556

          Nothing really innovative has happened in firearms since the AN-94.

          • Green Hell

            Not necessarily about inovation, but about overall well thought design. That’s why I’d really like to get my hands on a real G-36. I’ve only got a gas operated airsoft replica, but really love the weight, balance and ergonomics. Of all the countless AR-18’s derivatives this one just seems to be the best. I just hope the “overheating issue” is more of a political stuff, than a real problem, just like an “unreliable DI M4’s”.

          • Uniform223

            having handled and fired the G-36 while on deployment (worked with Latvian soldiers)… its a pretty cool weapon. It isn’t the greatest thing since sliced bread but it is pretty cool. I shot the G36K with the dual optic set up. Seemed like a great idea at the time but I couldn’t catch on to it. The sights were just too small for my liking (with little to no eye relief). I prefer the ACOG with that mini red dot sight set up myself…

            http://41.media.tumblr.com/tumblr_mb59r5uNCC1r9khx4o1_500.jpg

          • The G36 is a great weapon with a major flaw. As a PDW (which is basically what the MP7 is, a PDW’ed G36), I think it’s a fantastic design. As an infantry rifle… There are definitely better rifles out there.

            As a squad automatic weapon (MG36) oh god please no god god no please no god

          • Kivaari

            With all the reports of the G36 barrels melting the plastic holding them in place, it seems like a terrible design. I don’t know much about them except for what I read on TFB. I wonder if the Germans have tried to come up with a new mounting system that can be installed in existing stock (with machining) or a new component that would allow for the reuse of almost every part.

          • On the contrary, the moving parts group is world-class.

          • Kivaari

            That was my point. It seems from reading here that everything about the rifles is great, except for the way the barrel rested in the plastic stick. That’s why I thought there must be a way to salvage every part, and come up with a more heat resistant block or heat sink. Even a new stock having the improvements, seems to this untrained person, that it would be fine.

          • Oh, misunderstood you. Yeah, a good start to developing a good next-generation assault rifle would be to take the G36 and change the receiver architecture. One notes this is pretty much what the Poles, Belgians, and Czechs have done.

            The best of these is probably the SCAR-16, but even it’s not quite optimized, as it derives from earlier requirements that the SCAR-16 and 17 share receivers. So the SCAR-16, light as it is, is actually heavier than it needs to be. The receiver is taller and the carrier much heavier than they need to be.

            I would love to see a SCAR-16 derivative with a shorter (top to bottom) receiver, the carrier’s extension chopped off, and the G36-style gas piston or possibly a DI tube in its place, and a new buttstock (perhaps just give it an adapter for the ACR Enhanced stock). You could possibly get the weight to be competitive with an AR-15 at that point.

          • mosinman

            like an aluminum reciever that’ll allow the reuse of the barrel and operating system

          • Kivaari

            Yup! Essentially every part should be usable after finding a new way to bed the barrel.

          • Green Hell

            I don’t get it, you mean that G36 is a PDW in a way that “it’s good to carry because it’s light, but bad to shoot because it melts?” or something? And also, what exactly MP7 has to do with it other than HK logo?

          • No, I mean that there are subcompact versions of the G36 (G36C, XM8 Compact Carbine), and that the MP7 is mechanically basically a hobbit-sized G36.

          • ostiariusalpha

            The action on the MP7 is a compressed version of the G36. They also both use virtually identical vented barrel tenons with steel trunnions molded into the polymer receiver.

          • Kivaari

            As a PDW the concerns over melting the bedding would not be a major problem. Giving an effective weapon to troops that would not be using them much, just packing them around. For front line infantry where the rifles get used often, the issue is more worrisome.

          • The EMI report suggests otherwise…

          • Uniform223

            The US Army’s Advanced Combat Rifle Program of the late 80’s and very early 90’s introduced hyperburst function before the AN-94

            Right now it seems the newest innovation in small arms in the realm of materials. I believe the next innovation is going to be in the ammunition. Specifically telescoped and caseless ammunition.

          • CommonSense23

            I always laugh at these videos. The single biggest innovation all the rifles had was the optics. Its been staring the worlds military’s in the face for so long, and took so long to finally figure out. Iron sights absolutely suck to use in combat.

          • Uniform223

            Optics were/are a definite game changer. I sometime feel like the odd man out because I still keep irons.

          • Bill

            Smart people running optics still keep irons.

          • Kivaari

            Except, when the weather is very wet. I have not fund an scope that works well in a PNW rain storm. All combat rifles should have good back up sights. The optics need to be much better than the early AUG 1.5x. Those I tried had very distorted images. Fast in some conditions and horrible for very close range.

          • 624A24

            Really agree with what you said, but what makes you feel that way about the AUG 1.5x? Just asking out of curiosity.

          • Kivaari

            I used them in bad weather. Rain pretty much ruined the usefulness. The lenses had significant edge distortion, in an already small space.The small diameter ocular lens, was too small. At close range, trying to move fast, the sight blocked too much. That caused delays in finding the target. I could do faster and better with iron sights. Optics have come a long way. Put Leupold Mk4 1.5 to 5x24mm scope on it, and wow. The larger FOV, brightness and clarity makes it far superior. The small 1.5x AUG sight could become useless when just a few rain drops fill the spaces. That design was poor 30 years ago. Put a larger, modern optic on it and it becomes much better. In concept it was a great idea. Like WW2 German optics, people overrate them. We have come a long way. When I can put a $200 Bushnell 1-4x24mm scope on a rifle, it is better than that early Swarovski.

          • jono102

            The 1.5 probably suited its initial target being used by conscripts, i.e. put the donut on the target and pull the trigger, but yeah as above, it can be the best glass in the world, but good for f all if it incorporated into a scope to offer a better complete package, so it was dated from day 1. That’s why I thought it funny to see units and services puchase late model steyr’s with largely the same designed scope, both fixed and railed version.

          • 624A24

            That correlates with my experience… served with a rifle with basically an AUG 1.5x scope clone. Its nice for 50-200m, but it’s poor in muddy, wet or dusty conditions (tropics). I probably spent more time using BUIS than I should.

          • Bill

            “That design was poor 30 years ago.” Thirty years ago it was the nipples, now it’s poor. And now it’s been replaced. I would also contend that it was no worse than poor. The low mag and donut reticle made it usable the majority of the time, particularly when compared against what else was available..

          • 624A24

            My guess is that optics just weren’t viable for general issue until relatively recently.
            For a long time (Cold War era?) militaries were large-sized and dependant on conscription and drafting.
            Scopes are somewhat fragile, complex and expensive to make, relative to the rifles themselves – not the kind of thing you’d want to hand off to a green soldier, let him toss it around then have to make another for him!
            I think it’s the end of the Cold War and the increased use of professional soldiers that optics really caught on. But its true that optics are a force multiplier, its could be part of why the AUG was so popular with armies in the past.

          • Uniform223
          • CommonSense23

            Thanks for bringing that up. The Song Tay raid should have been the defining moment that the military should have realized iron sights are absolutely horrible for combat shooting.

          • Kivaari

            Poor for night shooting. Since much of our activities take place after dark, the clinging to iron sights wasn’t a great idea. Other nations had used tritium inserts or larger settings allowing more light to get through.

          • CommonSense23

            They are poor for any form of combat shooting.

          • Kivaari

            I wouldn’t call them poor. They have been eclipsed by much better optics. There will always be a need for iron sights.

          • CommonSense23

            They are slowly losing favor. And they are poor. Just cause they were the only choice for so long doesn’t mean they were not crappy.

          • Uniform223

            US Army and Marines still train and qualify with iron sights. They might not be the main form of shooting now but they are a basic skill set to have. I met a guy at a carbine course and he scoffed at me for still having iron sights on my weapon. Turns out that civilian never shot his rifle once with iron sights.

            I put up those articles to show that there were times before now that optics were used. It just that at that time the technology wasn’t there yet. Look at pictures of soldier and marines in the very early years of Iraq and Afghanistan, not everyone had optics for their weapons… TRADOC wasn’t as up to snuff and Supply was lacking (you mostly see SF types with optics). Before it became widely adopted only SF units had optics for their rifles and carbines. At one point it was just a matter of funding. At another it was just a matter of training. Luckily though we get some high speed stuff now.

          • Bill

            Until my EOCheck gets here I’m running irons only, and if I can do it, anybody can.

          • Kivaari

            Not many scopes made before 2000 withstood the rigors of warriors. The best scopes during the Vietnam era were not nearly as tough as they should have been. A Redfield 3-9x scope on a Remington M700, failed in Vietnam just like they failed in a rain storm or snow storm in Western Washington. A proving ground called the Quinault Ridge would show you how good a scope you really bought. Almost no scope could last a season, unless it were a Leupold.

          • Bill

            Once we stopped fighting in ranks like at Gettysburg we should have realized iron sights were horrible. And still a lot of troops fell to guys hiding behind trees hundreds of yards away with literally iron sights. Optics are good; good shooters are gooder.

          • CommonSense23

            Look at what you just said. Guys who are hiding. Irons work alright for the guy who is taking his time to take his shot, has a couple of seconds to line everything, then fire. For the guy who is ducking in and out of cover, trying to find someone who is doing the same. And has heard rate between 120-180. They are incredibly hard to use.

          • Uniform223

            “Optics are good; good shooters are gooder.”

            my grammar nazi is coming out…

            > optics are good, good shooters are better

          • Kivaari

            It took almost 150 years of research to get optics as good as we have today. Look how some of those newer devices now have issues. I’m still waiting for my EOTech refund.

          • Kivaari

            The Raid, scared the crap out of PAVN. It spurred them to move the bulk of the POWs to Hanoi. That greatly improved the morale of our people.

          • CommonSense23

            I personally believe the reason why optics, suppressors, hearing protection, and all the current bells and whistles of current smalls arms and infantry/sof equipment is finally getting where it should be is, the US military has never really placed the individual weapon and equipment of the rifle man a priority since WW2. Which I can’t really blame them.

          • mosinman

            nobody seemed to put much priority on it till “recently”

          • CommonSense23

            Cause until recently, as much as everybody talks about supporting the infantry. The infantrys equipment was the least important thing on the battlefield. Planes, tanks, ships, subs, all took the priority. Couple that with general incompetence of the military in actually recognizing and fixing a problem.

          • mosinman

            i don’t think that’s going to change much as important as infantry is, the tanks, planes and ships are much more powerful.

          • 624A24

            Arguably due to the rise of “police actions” by the US post-1990, in contrast to conventional wars of the past.
            These less-conventional/not-classical-war-but-still-war (the proper term eludes me) are more dependant on the infantry than tanks and planes. Stuff like Somalia, Afghanistan and Iraq 2003. With the infantry at centre stage it’s natural that increased attention is paid to their equipment.
            Contrast this to the Cold War era (the old Cold War that ended in 1990) when war was expected to be large-scale maneuvers across Europe. Air superiority and armour were priorities – both jets and tanks were in perpetual states of development and upgrading.
            The infantry were expected to die in large numbers, so why equip them so well? (I’m an infantryman, not happy about this)

            TLDR: different kind of wars, different emphasis on different branches

          • Kivaari

            I’d call some of these recent actions to be pretty damn close to “real wars”. Our two ventures into the SW Asian wars certainly were complex and pretty damn large scale.

          • 624A24

            I certainly ain’t disputing the wars’ scale – I can’t imagine my country’s armed forces deployed like that when things aren’t SHTF at home.
            But these campaigns are arguably the largest modern unconventional wars in recent history.
            Military forces aren’t fighting like how an army fights another. Infantry aren’t creeping their way through impassable terrain to secure cross-roads for a decisive division-level armoured punch. Air forces aren’t vying for superiority, SAM units are almost nil and tanks aren’t playing their deadly games of sabot-tag.
            Now it’s the infantry kicking doors and searching mudhuts for a shadowy enemy that somewhat resembles organised criminals, tanks are (mostly) invincible close fire support, and those agile jets are instead dropping bombs without fear of return fire.

            TLDR: It’s still large scale, but the wars in question are unconventional.

          • Kivaari

            Did the Cold War actually end?

          • 624A24

            Given current events, probably not. I was trying to mean the fall of the Iron Curtain (the old one, in case a new one appears) and the dissolution of the USSR.

      • kregano

        That’s the curse of the non-AR/AK rifle: they all cost twice as much or more than a basic AR/AK, so less people buy them.

      • Kivaari

        The ARs still represent one of the best affordable rifles around. Some of the ARs that hit well over $2000, can be had while the Europeans rifles remain unavailable. If I wanted a $2500 rifle that will have support from the makers, I’ll just buy a very nice AR15-based example.

    • Green Hell

      But it’s a fact that AR-15 is still the lightest of 90% of it’s “replacements”, swarming over the past couple of decades. Also, it’s still the most balanced, thinest and handiest of them all. Here’s basicly all the things guns like ACR were trying to “fix”:
      A: Replacing the charging handle.
      B: Adding the folding stock.
      C: Replacing DI gas system with a piston one (which arguably did less for increasing the reliability of the system then PMAG’s).
      That’s about it, not to say that all of those mods are allready available for AR-15 by now, and cheaper. Now tell yorself if the guns like ACR are really worth the weight (pun intended) and money.

      • tb556

        Nearly all of them are basically just updated AR-18s with rails.

        • ostiariusalpha

          The SCAR is a tappet system, it has nothing to do with the AR-18.

          • tb556

            LOL. Oh you mean the op rod link in the AR-18? All they did was make the op rod part of the carrier. Even the charging handle comes out the same.

          • ostiariusalpha

            Yes, the op rod is part of the bolt carrier on tappet operation firearms. Long piston stroke guns like the AK, M1 Garand and M14 also keep the op rod attached to the carrier, but that doesn’t mean the SCAR is just another version of a Garand. Tappet guns are their own thing; they are not an updated AR-18 or AK.

          • tb556

            The differences between them are insignificant, for all intents and purposes, they are both short stroke piston guns with detachable magazines and folding stocks. Nothing wrong with that, the FNC was an updated AKM just like the SG550.

          • ostiariusalpha

            No, the differences are actually pretty significant when it comes to simplification and weight savings. Tappet guns only require one recoil spring, just the same as long piston stroke guns, but true short piston stroke guns need a more complex (and heavier) arrangement to reset the piston and bolt assembly separately.

          • tb556

            Sure its simpler but your fooling yourself with the weight savings and reliability. I had a AR-180B with plastic lower and it weighed 6 pounds. A SCAR16S with a plastic lower weighs 7.25 pounds.

          • ostiariusalpha

            The SCAR 16 has the same upper receiver and nearly the same size bolt carrier as the .308 SCAR 17; b-duh, it’s heavier than an AR-18 that has a rather flimsy handguard and an airsoft-worthy lower with a fixed stock. The thing is, if you were to take the SCAR’s tappet system and retrofit it into the AR-18, that 6 lb. rifle would be even lighter than it already is.

          • The AR-18 is not nearly as light as people think:

            http://www.thefirearmblog.com/blog/wp-content/uploads/2016/01/1009151747.jpg

            Sling’s about 0.126 kg, so it’s 3.264 kg (7.197 lb), still heavier than a SCAR.

            Or, you mean a B model? Those are pieces of crap.

          • ostiariusalpha

            I was indeed referring to tb556 and his B model.

          • SCAR has a tappet descending from the AUG, and a bolt carrier derived from a G36.

        • danmanmain

          Ain’t that the truth.

      • CommonSense23

        A. The charging handle always makes me laugh. The number 1 complaint by a large margin when I got to evaluate the new MOD1s for the SCAR was the changing handle. I think it was Nate F. who said it best. “The AR15 has the worst charging handle when you need it and the best when you don’t.”
        B. They are useful, but not as useful as they are made out to be.
        C. I think people are just coming around to how reliable the DI system really is.

      • tb556

        If I didn’t own a 5.56 rifle already I would probably get a MCX in a year after it goes in to Gen 2 or 3. It would be sweet to switch barrels and change the twist and length for lighter or heaver loads for varmint or deer. That would make me pony up my money. Unfortunately it will probably never happen since it’s geared towards military/law contracts I don’t think they will ever make a 1/12 or 1/10 twist barrel. For now I’ll stick to my out of production SIG556 and 69 gr SMK.

        C: I know the internet loves PMAGs but I wouldn’t use anything other than Lancer or USGI.

      • Tormund Giantsbane

        I’m pretty much completely in favor of keeping the AR-15 design when the military upgrades and just adding the kinds of improvements that most civvies have been doing for years now. Free float handguards, folding sight systems, ambidextrous safeties, better charging handles, better ergos on grips and stocks etc. Do it right and the military could use one lower and 4 uppers and outfit every non specialist unit with carbines, PDWs, SPRs, and LMGs.

        That said, there are weapon systems out there that could provide excellent service to our armed forces. The question is just whether or not you think they are worth the investment.

    • Kivaari

      I have a Colt M4 SBR 11.5 inch barrel having the new “SOCOM” profile. It is heavy.
      Heavy enough to make me buy a new Bravo Company light weight profile. It is odd to shoulder the thing when I was used to the 16″ LW tubes. Not a bad thing for most people. It certainly works as a heat sink, and it is stable. If you ever went from the M16A1, to the M16A2, it struck most of us a feeling like a real rifle. I liked it when I was young. Now I am a weenie.

  • BrandonAKsALot

    Thanks for taking the time to do this. It as very interesting and informative. Any word on whether that carrier will be welded in production? I’m sure production models would at least have less nasty looking welds.

    • I am not sure. The carriers and bolts on the guns at SHOT 2015 looked completely different (much nicer), but I was not allowed to take photos of them at the time. I don’t remember them being welded, but they could have been. They had no problem with me taking photos of the internals this year. The receivers and hardware of the guns at SHOT 2016 looked much more finalized, on the other hand, so I can’t say whether one variant was older and the other newer. The guys at FB Radom had indicated that the finish on the bolt group of the 2016 model was the newest finish (the 2015 guns had a very nice purple-blue).

      Keep in mind that the gun is still in development. I hope the state trials of the MSBS wring out any flaws in the design. The basic foundation is solid, and there are some basic mechanical improvements in the MSBS vs. the ACR, so I’d love to see the gun worked into something really competitive.

      • BrandonAKsALot

        Thanks. I’m also really hoping it gets off the ground. It could offer some interesting competition.

  • MPWS

    To have bolts on mobile assembly subject to shock is not good idea. To prevent them from getting loose you have to toque them real heavy and then cannot take them out again. Welding carrier out of two pieces is completely out of book (cooling, distortion, alignment….); why not to take use of already introduced bolts instead? It’s a hodgepodge.

    So, all powder in copying G36 is shot out. What’s next in the door of rifle progress? I want to see something real novel.

  • Hokum

    Thanks for this article, Nathaniel!

  • NewMan

    Thanks for taking the time to write this article.

    However, so far this rifle doesn’t sound good to me. “weld” carrier just isn’t a good idea. There is nothing ‘special’ about this rifle that it required a ‘weld’ bolt instead of just machined it out from one piece.

    • BrandonAKsALot

      HK welds the carriers of all the roller delayed guns. Nothing wrong with it when it’s not bubba in his garage. Using the proper welding machine and filler or lack thereof and heat treating is very viable.

      • Tom

        Exactly we have been welding and brazing weapons since we first started working metal, when done properly a weld is just as strong as milling from a single lump of metal.

        • tb556

          do you really think that should be necessary in 2016 when we have 5 axis CNC machines?

          • Dual sport

            1. Strength depends on the tensile strength of the base and filler metals but welds are often stronger than base metal.
            2. Machined parts and welded parts are simply two tools in a manufacturer’s tool box, not better or worse than one another.
            3. It all depends on which Bubba and which manufacturer one is talking about. I have witnessed great and piss poor welding and machining from both.

          • tb556

            It may work but I still don’t see the point in going back to 1960s firearm manufacturing techniques when the technology exists to not have to do that especially on a gun that they will probably want $2500 for.

          • mosinman

            from a military standpoint it makes sense, especially if you can make more weapons faster that way.

          • Dual sport

            1960’s? Try the beginning of metal working time. Welding is like rifles, when it works, it works. Sure, we’ve added electricity and computers but big whoop. You still have to work that puddle and eliminate defects.

            There are many here who still believe the AK family is an inferior system due to manufacturing processes but it will kill you. There is no superior manufacturing process, just like there is no superior rifle action. (I’m assuming we’re talking about processes and rifles that actually work.) you decide what you like and need and that’s where you spend your money.

            Think about this. How many newly constructed buildings are being machined? How many will be here long after we are gone, barring a direct hit from something environmental or weaponized?

            Btw, those welds in the pictures did look horrible. They would have never passed a competent visual test. Lol.

          • Tom

            Since its not any weaker if its easier to make that way then why not.

            An assault rifle has to be easy to produce if you can save time or resources without compromising function and reliability then there is no reason not to do so.

  • Kelly Jackson

    The only bullpup I’m really interested in

  • Uniform223

    Great read. I guess the similarities are truly skin deep. I like the fluted barrel on the MSBS.

    • There are some conspicuous similarities (shape of the bolt carrier for one), but overall I think the strongest connection you could make would be that MSBS is perhaps “influenced” by the Masada.

  • I want one! I hope this is the MSR I’ve been waiting for.

  • Cuvie

    The Remington Defense model also had a bunch of issues with accuracy and reliability. They did manage to get the weight down a bit, but they had to do away with the folding stock and quick change barrel for that. It was still heavier than an AR-15

    • Yeah, the ACR is kind of a turd. I am sure it could be perfected, but it would at that point still not have all that much to offer vs. an AR-15.

  • Kivaari

    I suspect the rifle you looked at was a prototype, considering the poor quality of the weld. If I had a say in things, I would try to figure out a way to not use a welded carrier. Once a final production rifle is served up, we will likely see a nicer weld. I know HKs use them as well, and they do hold up.
    The auto-sear looks like it will take quite a bit of use. It is well placed and looks quite sturdy.
    Just counting the hex screws, including those on the carrier, strikes me as the wrong way to go. “Extra” screws means it is too complex. That’s just me. I want something like that.

    • They are all prototypes (or pre-production at best). I would expect the Polish state trials to result in several changes to the rifle.

  • Rusty S.

    Great article, Nathaniel! I really enjoyed shooting the MSBS, even in its “rough” form.

  • The EMI report wasn’t dismissed officially, there was a soldier survey taken by the Labor Party that reported high satisfaction with the weapon. This cannot counter a scientific analysis.

    There’s no evidence that I know of suggesting the EMI report was flawed or rigged. Frankly, saying it was suggests a considerable conspiracy against HK that is very difficult to believe. Note that the EMI report not only outlines problems with heat, but also humidity and temperature.

    In contrast, the criticisms against the AR-15 have been well and truly refuted for the most part. If we take for comparison the 2007 dust tests, we know those had major methodological issues, which you can explore for yourself here. We have no comparable analysis of the EMI report, and no compelling reason to doubt the veracity of their results.

    Having said all that, we tested a G36C at TFB and didn’t immediately find anything wrong with it. I even shot that example, and didn’t have any accuracy issues with it. The testing we did was not as comprehensive as the EMI testing, however, and I am inclined to weigh the EMI report more heavily than the informal testing we conducted.

  • John

    Great article by TFB, by the way. I hope you all will write more of these in the future.

  • I agree it doesn’t score as well in the “looks” category.

  • ostiariusalpha

    You aren’t seriously so naive as to suggest that all polymers are the same, are you? The polyethylene plastic that the AR-180B stock is made from is not even close to as durable as the Nylon 6 variant polyamide that the Glock frame uses.

    • tb556

      LOL I would love a link to the insider information you have on the polymer Armalite used in their lowers along with the tensile strength rating that you seem to be privy to.

      • If I have several years’ experience with one, does that count as insider information?

        Plastic, you know, is not a bad material. However, it has a much lower strength/volume ratio than other materials. This is the same problem people trying to make 1-1 polymer replacement lowers for the AR-15 are having. The lower receiver on the AR-180B is underbuilt for the material made for it. It flexes and rattles quite a lot, and there’s a definite need to be gentle all the time with it. They are not particularly accurate weapons, as well.

        • tb556

          Did it break?

          • Mine did not, but that doesn’t mean it was a good rifle.

      • ostiariusalpha

        If you’re truly interested in polymers than the Handbook of Engineering and Specialty Thermoplastics is a pretty exhaustive resource. If you just want a table of tensile strengths than a quick trip to Google will do the job.

        • tb556

          So what your saying is you don’t know what Armalite used. If you do, I’d love a link to your source since Glock frames are superior to the merterial used on a centerfire rifle.

          • Yeah, they are. Armalite used a really crappy plastic and a poorly dimensioned lower for the material.

  • Bro, I own Glocks and love them. I owned an AR-180B, too, for several years, and it’s a piece of crap.

    • tb556

      I’m curious, what was wrong with your gun? I never had any issues with mine besides the trigger being on the heavy side. When they came out they weren’t any crappier than the SAR-3 or mini-14 they were competing market share for. Since AR-15 prices have fallen so much in the last 15 years there was really no point in Armalite to continue making a low cost alternative to their ar15 models.

      • Incredible upper and lower receiver slop (the lower hinge pin hole did not break on mine, but looked like it was on its way), poor reliability, and poor accuracy.

        I sold it several years ago, and bought a Colt 6920 and never looked back.

  • NOUNBELIEVER

    MY TWO CENTS about the AR…I find the aluminum receiver very weak and the stock attachment point is the place I expect to fail first…the gas piston, adjustable gas pressure cylinder are items I would prefer with the AR…and an under folding stock such as the AK or perhaps a wire sliding stock such as the M3 / M3A1 submachine guns….no protruding handles on either side of the components…flatter shape to allow he weapon to be carried on you back in an ambidextrous manner…protrusions stop that