Benelli MR1 Carbine (Civilian Beretta Rx4 Storm)

Benelli, not wanting to miss out, has entered the lucrative black rifle market with Benelli MR1 Carbine, a 5.56mm gas piston operated rifle.


Benelli MR1 Carbine

The MR1 Carbine is the civilian version of the Beretta Rx4 Storm (which never took off). Benelli, a subsidiary of Beretta, designed the ARGO gas system used by the MR1/Rx4 and manufactured both the MR1 and the Rx4 Storm.

Beretta Rx4
Beretta RX4 Storm with accessories. The collapsible stock is not available currently on the RX4.

What differentiates the MR1 from other 5.56mm rifles is the gas system it uses. Originally the Auto-Regulating Gas System (ARGO) was designed for the Benelli M4 Super 90, better known by its US Military designation, the M1014 Joint Service Combat Shotgun. Benelli then adapted the system for their ARGO line of hunting rifles (branded the R1 in the United States). In 2005 the Beretta Rx4 Storm, a tactical version of the ARGO rifle, was introduced and marketed to law enforcement. As far as I know the Rx4 has never been available in a select fire variant but they decided to market it to civilians as the Benelli MR1.

Benelli M4 2
Benelli M4 Super 90 / M1014

Benelli ARGO EL

The ARGO gas system has an interesting short stroke piston design. Gas is trapped very close to the chamber. The high pressure gas ensures reliable cycling regardless of ammunition. This means that it can cycle any shotgun shells, regardless of the load. For a rifle it means the barrel can be very short and a suppressor could be fitted without any cycling issues. This gun is just asking to be converted into a Short Barreled Rifle!

The gas is then fed into an expansion chamber. The pressure in the chamber drives the piston assembly, which has dual rods. The high pressure is regulated by a release value. These diagrams should illustrate how the system works.

Benelli Argo-1

Argo System

The receiver is made of aluminum, it is fully compatible with AR-15 magazines (including the 100 round drums) and, like all Benelli shotguns and rifles, the main spring is placed inside the butt stock – meaning a folding stock is not an option, although hopefully an M1014 folding stock will be made available.

MR1 Specifications:

Caliber: 5.56mm NATO / .223 Rem.
Barrel: 16″. Hard chrome lined. 1:9 twist.
Rear Sights: Military-style Aperture
Weight: 7.9 lbs.

The MSRP is $1299. I think they have priced it right. Although not cheap, and they can do better than the one five round magazine they ship with it, I doubt they could sell it much cheaper.

MR1 with 5 round magazine.

Steve Johnson

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


  • CMathews

    I have been anxiously awaiting this day. I love the way this carbine looks and feels. Haven’t had any range time with one, but I’m sure looking forward to it.

  • RP

    I adore my Benelli shotguns and I want one of these too. ASAP.

  • B Woodman

    Hmmm. I wonder how long it will take them to come out in other calibers (.308, 6.8 SPC, 6.5 Grendal, etc)??

  • Matt Groom

    I like the pistol grip stock version, and the conventionally stocked version. The collapsible stock version is quite simply hideous. At least it’s an original design, but I am so OVER the 5.56. I wish somebody would invent a new caliber already.

    I’m not going to buy one, but I’d pick one of these before one of those stupid piston driven ARs that everyone keeps producing.

    • “but I am so OVER the 5.56. I wish somebody would invent a new caliber already.”


  • Well, looky there… a California legal configuration… I’m sure that didn’t happen by accident. Hope it ambidextrous. đŸ™‚

  • I wonder, does it take M16 mags?

    • Stephen, yep. STANAG magazines are M16 magazines.

  • Whatever

    Maybe this is just me, but I don’t care for designs that look like something Frankenstein would make. I like designs that look purpose-built, not designs that first went one way and then were retrofitted to do something else.

  • Matt Groom

    I wasn’t being sarcastic, Steve! I really think we should all join hands, take a deep breath, and adopt a 6mm cartridge as the new universal standard because it’d be bigger than a .224″, faster than a 6.8, and have better BCs than any practical length 6.5. Yes, the 6.5 and the 6.8 are more powerful, but if I wanted power, I wouldn’t be looking at a 5.56 platform.

    Can’t we all just get a long gun… caliber?

    • Matt, fair enough. I don’t want to get off topic but I get your point, although the trend is towards heavier bullets for use in shorter rifles. 6mm is a fine caliber, I know ’cause I shoot .243.

      Getting back on topic, strangely enough the R1 / ARGO is not available in .243 or 6.5 Swede, or anything under .270. With the MR1/R1/ARGO/m4 being available in .223,.300 Win. Mag. and 12 gauge, there is probably very few cartridge the design couldn’t be adapted to take.

      I must say, I like the idea of an action that is built to be semi-automatic. Most, if not all semi-auto black rifles are military actions designed for full auto fire. This action was never intended to have a rock-n-roll switch and so they have been able to do things like have the gas trap right in front of the chamber, something that would probably melt if it was fired constantly in full auto.

  • jdun1911

    It probably be sub 1k once the rifle reach retail. However even with that price point I doubt it will see decent sells.

    What the deal with the slope down stock?

  • michael

    it does look different. At first i was in the man that looks crap and then the more i looked the more it grew on me.

  • Whatever

    “At least it’s an original design, but I am so OVER the 5.56.”

    The 5.56x45mm seems like it’s akin to democracy, a horrible solution to the problem yet better than anything else put forth. There are more powerful military cartridges out there like the 7.62x51mm, but they are much heavier and have much greater recoil.

    The one thing that I think the 5.56x45mm has going for it is efficiency; it seems like it can get a meaningful weight projectile close to 3000 fps with less powder behind it compared to other cartridges. It seems like when you start moving up in bullet weight beyond around 75 grains while trying maintain a velocity close to 3000 fps, efficiency starts going down.

  • I’ll pass…

  • B Woodman

    Are you sure you mean the 5.56x45mm? That’s the round that’s used in the Russian AK74 (update of the venerable AK47).

    Or do you mean the 5.56x54mm? The M16/AR15 round.

    Matt Groom:
    “The collapsible stock version is quite simply hideous.”
    As far as that goes, I try to look beyond the ugly factor & ask, does it work? And how well?
    There was an expression originated by the Bauhaus movement of pre-Nazi Germany, “Form follows function.” Basically, whatever the thing being designed is supposed to do, that’s what it will look like. No more, no less.
    So the collapsible stock may look ugly (for now), but it’s doing what it’s supposed to do. And it looks it. Someone else later on may design a more “elegant” stock. Maybe you?

  • Matt Groom

    B Woodman,

    I’m sorry to inform you that you are incorrect as to the terminology of the 5.56 NATO, which is indeed 5.56x45mm and not 5.56x54mm as you suggest. The Soviet equivalent fielded with the AK-74 is the 5.45×39.5mm, which is in my opinion a superior cartridge design except in the area of bullet caliber selection, which is .2205 and not .224. They are quite similar in concept and terminology, and it is an easy mistake to make.

    The collapsible stock on the MR-1 Carbine is, I assume, of the same type as it is on the Benelli M1014, which means it only has two positions, open and closed. The collapsible stock designed for the AR-15 series of rifles is based on a style that emerged in the late 1960’s which had 4 positions of adjustment, and is more aesthetically pleasing to boot.

    That style has been considered obsolete since the 1980’s and has long since been replaced with the now common 6-position M4-type stock, which itself is being rendered obsolete by newer aftermarket designs which offer infinitely more adjustability, not just in length, but in cheek height, storage compartments, and so forth.

    This means that the Italian design is done not because of the technical difficulty of creating a stock which has more than two positions, but because of the desire to create a certain aesthetic model, which to my eyes is quite ugly, as well as lacking in essential function that a collapsible stock must possess, adaptability. The entire rifle seems designed with a certain style and flare in mind, and perhaps the desire to maintain that unique flavor has created certain components which are unnecessarily awkward and lack essential function. That being said, it still seems like a good design overall.

    The famous German firm of H&K offered nothing but two position stocks for years and said “If you don’t like it, buy something else!” and when many people did, they quietly changed their tune. It would be a shame to see Beretta make the same mistake.

  • Allen

    This new Benelli MR1 has Italian design written all over it. Almost to the point of overkill. Sorry fella’s but it’s just too streamlined and outright sexy for this ugly old man. But it is about the mechanics and not not aesthetics.Time will tell if it’s reliable. Think I’ll stick to my old school AR’s, thank you.

    I’m aslo wondering why Benelli didn’t chamber the MR1 in 5.45X39? I whole heartedly believe that the 5.45X39 is far superior cartridge design to it’s western counterpart the 5.56 NATO. Wait a second, that’s impossible! There is no superior or “magical” properties involved within any particular cartridge design of the same caliber. I forgot, all .22 caliber centerfire rifle cartridges are created, or can be willfully manipulated, to shoot exactly the same. Shame on me.

  • Matt Groom

    I never implied that it shoots better, I merely said it was a better cartridge design. The 5.56 was designed to launch a 55grain, lead cored projectile through a Steel helmet at 500 yards, which is a rediculous test, but the 7.62 NATO could do it, so the Army insisted the 5.56 do it too.

    All experience hath shown that the 5.45×39 shoots far WORSE than the 5.56. I just like that it’s designed for longer bullets which could have a higher BC (If they were a standard caliber) and potentially better fragmentation capability at lower velocities because of their length. That would all be dependent on better bullet designs, which at this point do not exist for the 5.45×39.

    Just try to find a boxer primed brass case in that caliber.

  • R.A.W.

    I don’t think that having the gas port and mechanism drilled close to the firing chamber would present a thermal challenge. If nothing else, you could make the gas system out of the same stuff as the barrel, which does not seem to erode unduly under full auto fire.

    I do think that the 5.45 compares nicely to the 5.56, if one compares the original loadings for each. M193 ball isn’t an especially awe-inspiring load, especially at range, and the 5.45 did have a somewhat better BC. M855 seems to trounce the old “poison bullet” 5.45 loads, but then there isn’t much published information on later 5.45 service loads, so perhaps they even the gap.

    Now, 6mm SAW, which looked for all the world like a scaled up 5.45mm; that was the stuff of dreams.

    Oh, and speaking of 5.45mm weapons, here’s a diagram of a Nikonov:

  • B Woodman

    Matt Groom,
    My apologies, my error. I should have had a reference in front of me when I wrote that last missive on the 5.56 vs 5.45.

    As to the stock, now I understand what you’re talking about. I thought it was only on the aesthetics.

  • Sean Ingram

    I’m interested in one that is chambered in 7.62×39 and uses AK mags.




  • Milt

    Has anyone checked it’s accuracy?

  • simpsomi

    As Milt says ….”any idea on the accuracy?” I have been searching the net for an aswer on that and have yet to read it.

  • Larry R

    On accuracy: G&A had one that shot sub moa groups. AR could barely beat two inches. Mine will shoot selected handloads into sub moa but even Fiocchi match with 69 SMKs is a 1.5″ proposition. The stock has too much drop for a scope in the extra high rings needed to clear the irons but a Brownells neoprene cheeckpiece works fine to fix that.

    As an owner of two R-1s (270 WSM & 300 Winmag), I think Benelli builds great guns. Both of them do one MOA or better. BTW the R-1 was never made in the real 270 WCF and IMO their choice of calibers is odd. No 9.3×62 and who would want a 308 when a 30-06 is available ? The addition of WSMs is just marketing as neither will do a thing the plain old 270 and 300 Winmag don’t already do. Short action cartridges in a long action…. why ??

    With the ease of barrel swaps, I hope MR-1 barrels come out for all the 223 based cartridges but with Benelli logic is not always followed.

    My R-1 270 WSM w/Nightforce 2.5-10×32


  • Barbara

    I purchased an MR1 about 3 months ago as I just don’t like AR’s but do like my Benelli M2’s very much. I have enjoyed the weapon and have fired about 2K rounds through it with no problems. I don’t know what it will shoot for a group as I never go onto the bench except for the initial sighting in. It does what I want and is pretty good at hitting most anything I aim at. I have an Aimpoint on it right now but will move over to a scope for coyotes.

    If you like the feel of a Benelli shotgun you will like the feel of this gun too. It is a bit heavy but not bad, and it comes on point very easy. It doesn’t have the big offset sight issue of the AR but does have some offset to deal with.

    It breaks down easy for cleaning if you know how to pull apart a Benelli shotgun but my intimidate someone the first time they pull it apart. I clean my weapons every time after shooting but this gun runs clean so that is up to you.

  • guido pagliai

    i stay in italy ,the rifle is good but too expensive in my country
    i prefer a feg .223 for money value.
    the benelli rifle is not catalogated as hunting rifle but tactical advance firearm.
    its only an export joke, no military use civilian use.
    in the middle……………

  • jsp


    you have the word “value” where I think you meant valve in the text.
    Right here: “The high pressure is regulated by a release value.” Please delete my comment after you fix it.

  • Pollux

    I don’t foresee popularity. $1300 for a trumped up shotgun receiver with a 1:9 pencil thin barrel with no threads? A thousand times pass, as a commercial investment. Please don’t mistake me, I think the gas system is much more functional than any bolt shearing piston AR conversion will ever be until a new lug system is devised (or a way to restore the order of operations). But I simply cant shell out that much money for a shotgun retrofit, the juice isn’t worth the squeeze. Might be a great gun, but I cant see it getting into the black gun treehouse for cool kids nor the budget conscious plinker/home defender market.

  • Bob

    I recently purchased the MR1 to go with my collection. I haven’t shot it yet but plan to this week. It is a very solid feeling rifle. I have taken it apart for an initial check and clean/lube. It did make me think some when I went to re assemble it but I should have no problems the next time. The only problem at this time I have found and corrected was the stock was lower when I tried a cheek weld on it. I purchased a padded cheek rest from Blackhawk and Voila, problem solved. I will report back after I shoot it on the grouping I am able to obtain.

  • Abe

    Looks cool, but it’s got a pussy caliber – please .30 anything over these mouse rounds.

    • Tom

      you guys who laugh at “pussy” calibers make me laugh and end up paying for my lunch quite a bit. how can someone with a .308 be outshot at 250yds by a .22wmr? oh yeah you are too busy overcompensating for something small with your big bullets. Yeah too much of a man to shoot a .22 wow

      • ken m

        abe your ignorance of the American .22 round is embarrassing. As a cop for 26 years, I can tell you every ER Doctor, would rather work on any gunshot wound, of any other caliber than a .22. see if you can find a picture of a persons chest after exploratory surgery to get all those small pieces of lead, out of the chest, so the pieces doesn’t work its way into some organ that will kill you. It’s not pretty, it looks as if Dr Frankenstein decided to make the chest look like a quilt. Here is the simple fact the .22 has killed more people in America, than any other round

      • JM-New Jersey

        As .223/5.56 go this rifle works fine and the round is not a pussy when a round is traveling at 2900FPS + at 100 yds. it is a nice solution for those of us who live in restricted states.

        The .308/7.62 is more powerful but i am afraid there are reasons why the military and shooting enthuasts prefer the smaller round.

        Under 100 yds the .22LR hollow point is a devastating round but with a 1300FPS muzzle velocity it drops off significantly between 50 and 100 yds.

  • Aaron

    I held one of these a few days ago, my impression is its just wrong it tries to do too many things at once, and it fails to do any one thing well, if you are not a fan of the ar platform for whatever your reason may be, I hear alot of whining about its unreliability in vietnam and the 5.56’s shortcomings with penetration and so on, both are pretty baseless arguments, the problems in vietnam were because of a combination of the powder being used lack of cleaning, because they werent issued kits, and they didnt produce the design that was tested and selected for service. just another example of corner cutting and penny saving, costing more in the end. So why complain about a problem that hasnt been an issue in 40yrs? I can understand Vets having a bad taste in there mouth over losing friends over that, It was a terible thing to have happen, our servicemen deserve the best. but that doesnt mean a rifle built 2 months ago has any of those issues. now onto the .223 that was the caliber of the MR1/R1 i saw, yes FMJ ammo isnt the best bullet, but as a civilian you dont have to use fmj ammo and its all about placement. my brother in law is a game warden and he catches more poachers taking deer with 22lr’s than any other gun, its all about energy transfer, a bullet that stops in the target transfers all its energy, a fmj .223 or .308 that goes through a target at 50 yds, they both will, is a waste. and the .050″ difference in diameter really doesnt matter, especially when most rounds in a firefight never find there target. Back to the MR1 id take my bushmaster AR or a M14 or an Ak over one of those goofy halfbreed italian rifles anyday, they are too expensive and not accurate enough and not proven, my 16″ bushmaster with 55gr FMJ BT AE ammo shoots better than 2moa, wich is the accuracy most get out of the MR1 sure there will be the occasional “match grade” accurate rifle but its the exception not the rule.

  • Tom

    Is it just me, or does the angle of the stock and the drop at the comb look pretty extreme? there is a reason most rifles nowadays follow the AR’s footsteps with the inline barrel and stock, all a drop at the comb does is add to muzzle climb. this rifle looks like its trying to be different and clever, just for the sake of being different and clever. I will keep my AR-15

  • AndrĂ©as

    Just reporting trouble with a mounted silencer. Dont feeding in a new round but travels all the way back to be able to hock up on a emty mag.

    Anyone with som tips?

  • JM-New Jersey

    I am in this ridiculously restrictive state and looking for an AR/AK platform that is legal here.

    The MR1 lacks a flash-hider, bayonet lug, adjustable or folding stock which makes it entirely legal (with the 5 round magazine). I can see that it has many flaws but can anyone recommend a better alternative?

  • Rob

    I own a MR1. I reload my ammo. I use 223 with 55gr nosler balistic tip using varget powder @ 27.5 grains. The gun oerates flawlessly. I have shot over 2000 rounds & have not had a problem. I mounted a Nikon 223 3×9 scope & i am putting groups of 3/4 inch @ 200 yrds. I reccomend this gun to anyone.

  • Rob

    I have an MR1. Great gun. One problem it’s a bitch to assemble the upper and lower after cleaning. If some one has a trick to this, perferably a video, I would like to see it. I watched the “mad Russian” on the you tube video do his and I can’t still figure out how he did it so fast. My other question is will they be making these in a bigger caliber like a 308/7.62 for the civilian market & does Benelli make a hard case for the MR1. Please advise.

    • Chris K

      Fellow MR1 owner, there are U-tube videos on the trick to mating the upper and lower assemblies. Have the gun in a yoke style holder with the stock higher than the barrel, ensure the two locking pins on the lower front are out and as you start to engage the upper pull the bolt back about half an inch. The upper should drop in and mate. Good luck

  • I just purchased this rifle a few days ago, removed the rear iron sight (not easy) and mounted a Vortex Viper PST 1-4X 24mm scope on it. I fired 200 rounds at the range today and was pulling 1 inch groups at 75 and then at 150 yards within 30 minutes of firing. This is by far one of the most efficeint and exciting rifles I’ve ever owned or had the pleasure to shoot. The rear iron sight requires the hands of Hercules to remove and the weapon’s reassembly is difficult the first time around, but the quality, accuracy, consistency and reliability of this weapon has created a life long bias toward Benelli firearms – I can’t wait to see what they design next!

  • Benelli Big Bad Gun

    I bought one of these rifles but it did not come with an instruction manual. Called Benelli and they said they would send me one. I never received it and no follow up from Benelli. I fired my rifle and it would jam constantly with different ammo and magazines. I sent it back to Benelli for service and they sent it back to me and said nothing was wrong with it but it kept jamming and misfeeding on almost every round. I sent it back again with an even longer description of the problems with sample fired cases. They sent it back to me and said that they had to replace the entire barrel so I’m guessing there was something wrong with it all along. I took it out to test fire and it performed better. It only jammed or misfed rounds every seventh or so rounds. With the cost of ammo being what it is now, I can’t really test fire it anymore. Hoping that when I can shoot again that it will function properly. I still think Benelli service is terrible considering this rifle cost me a bundle of money! I also think it’s quite cheap of Benelli to supply only one magazine with this rifle. Additional five round magazines cost $85?

    • Charlie

      Me and my brother bought one each and they BOTH keep jamming and misfeeding constantly despite using different mags and ammo…
      Design flaws??? What to do…

      • Frank

        Try one type off ammo, then clean entire riffle. Then next type off ammo. My Mr1 do not like some ammo.

  • Greg

    My Argo do not like 5.56 NATO, but never any problems with 223rem. Any other with the same issues?