Sig Sauer MCX Black Mamba–SHOT Show 2015

You can't buy happiness, but you can get a good dose shooting a suppressed MCX in full auto.

You can’t buy happiness, but you can get a good dose shooting a suppressed Sig MCX in full auto.

We’re reporting on two sides of Sig today. The first, their new P220 in 10mm, demands attention. There’s virtually no way to ingore the gun, as I discovered on the range during the SHOT Show. It is loud.  On the quiet side, Sig’s new MCX rifle family chambered in 300 AAC Blackout is going to cause quite a stir.

I love the 300 AAC Blackout for its versatility and the fact that it’s just plain fun. These rifles take that fun and utility to a whole new level. Other calibers including 5.56mm and 7.62×39 will be offered too, but I think the Blackout is the one to use on this platform. The rifle was designed for the 300 Blackout by using an auto-regulating piston gas system, so function and reliability are maintained across the wide variety of ballistic choices both suppressed and unsuppressed. Migrating 300 Blackout support to an existing platform can be problematic as getting gas and recoil balance right supersonic, subsonic, suppressed and unsuppressed is quite a feat.

Affectionately called “The Black Mamba” by a growing number of people inside and outside of Sig, the CMX leaves the gates with three primary configurations. The rifle features a 16-inch barrel and a choice of four stock options: a low profile, side-folding skeletonized stock, a telescoping stock, a tubular side folding stock or a folding telescopic stock. The short barrel rifle version (NFA item) comes with a 9-inch barrel and the same choice of stocks. The pistol version features a side-folding SBX Pistol Stabilizing Brace.

The Sig MCX SBR configuration.

The Sig MCX SBR configuration.

What’s in common across the line is modularity. Barrels can be easily swapped between 9 and 16-inch versions and caliber change is an easy operation, calling for a new bolt face in the case of 7.62×39. All models also offer standard upper compatibility so new uppers can migrate legacy lowers. Key mod rails, full-length Picatinny rails on top and iron sights round out the packages.

I shot the MCX SBR with the new Sig SRD762 QD silencer and Sig’s 300 Blackout 220 grain subsonic. Oh boy. I don’t often gush, but I sure did with this package. It probably didn’t hurt that one of the many MCX rifles I fired that day came with a full-auto happy switch. Recoil is virtually non-existent, bordering on generation of an anti-recoil field. Noise? There is none. Well, OK, a little, but not much. Most of what you hear is the thump, thump, thump of those big heavy rounds hitting the target.

The SIG MCX rifle carries an MSRP of $1,866, while the SBR variant has an MSRP of $2,058. The pistol with side-folding SBX has an MSRP of $2,132.

About the author: Tom McHale Literary assault dude writing guns & shooting books and articles. Personal accountability rocks!

{ 15 comments… add one }
  • Jon February 22, 2015, 8:49 pm

    I see several negative reviews. Sig is a good name. Why tarnish it with sub par weapons. The old German weapons function proper. If you need a “clearance” letter I won’t buy it. Big brother has a firm enough grip without additionl paperwork. Good luck sig. Perhaps, go back to German style and production

  • Sean February 4, 2015, 3:26 pm

    I’m still waiting for the .357Sig 1911 Fastback that Sig debuted at SHOT 2 years ago… I do enjoy the old Sig quality but with their new stuff, ‘I’ll believe it when I see it” comes to mind.

  • T. Kelly February 4, 2015, 1:48 pm


  • Chris February 4, 2015, 11:32 am

    Release date?

  • sigsaulter February 4, 2015, 9:12 am

    Remember the MPX from Shot Show 2-0-1-3???? Yeah, 2013 year??? Today it is past Shot Show 201FIVE!. 2015. TWO years later and they still have not released the MPX. Why? Because Sig has been pumping out guns to capture market attention and used loyal customers are stooges, guinea pigs and free R & D mules to vet their inventions. Multi-generation Sig 556 Russian and Sig 716 rifles, to name a few. The .22 conversion kit on the Sig 22x line of pistols is a joke (doesn’t work reliably on nearly every type of ammo). The release now of the Sig 556xi has field reports of major malfunctions – piston being seized in the gas tube.

    and we wait for the MPX.

    Why then, should we even consider another M-something gun from them with this recent track record? I used to be a loyal Sig fan but even their handguns are huge disappointments in quality since their German manufacture days. Now, Sig Sauer is only a name, used deceptively with a former incredible pedigree, to pump out adult toys that don’t last.

    • Chris February 4, 2015, 11:38 am

      I believe the MPX has been delayed due to the ATF having a problem with their new muzzle device, they say it’s a silencer, Sig disagrees and it’s become a matter of the courts.
      This on the other hand doesn’t have some fancy new muzzle device, one model is a perfectly legal 16 inch barrel so there should be little delay in its release.
      As for the 556xi, what problems are you referring to?

      • sigsaulter February 5, 2015, 9:40 am

        I have had the weapons I cite as problems so I have had direct experience with their quality control issues. Sig today, is nothing more than a name. NOTHING they make or sell today has anything to do with the former manufacturer of German or Swiss days. Armalite is another example of owning the name but it is a totally different company than the original Armalite. BTW, not meant to be a bad thing for Armalite but definitely a perspective that Sig buyers need to be aware of.

        • Dzlfnatk December 2, 2015, 7:10 pm

          The H&K MR762 was delayed for years. I followed that rifle and it’s escalating price tag until it went north of $4k (not even iron sights) while it was reported to have ongoing performance issues. I perused companies such as Sig, AAC, Ruger, etc. who were making reliable .308 rifles at almost half the cost of the H&K. There are other AR style makes that while expensive, they are well made and reliable. I have little use for a small rifle in a small caliber so the Sig MPX was not on my bucket list. It’s cool though. I understand the ATF went after Sig’s MPX for somethng that amounted to a misunderstanding on their part for what it’s worth.

      • sigsaulter February 5, 2015, 9:47 am

        The MPX delay has nothing to do with the baffle version. They have several other versions that were shown and could have been released with no legal issues. That model was one of several. As a matter of fact, has been showing the pistol on their website for over 2 years but it is not available, meaning that was the original intended release product.

        I think the thing to do with Sig long arms is to ignore what they are doing until several years and dozens of unbiased reviews develop over a product. Sig used to be my religion but from a variety of problems with their US made pistols and long arms, I no longer consider them an option. Not with so many other choices now such as IWI Galil pistol and rifle and the Tavor. LWRC, Armalite, Colt, Steyr, Walther just to name a few.

      • sigsaulter February 5, 2015, 12:48 pm

        Another reason to avoid the MPX, MCX, MFX, any new Sig product. They cannot even get the Sig 556xi to work. Here is a video with more issues.

        Go to 5:35 on the video. Gun will not function!

  • Jeffrey L. Frischkorn February 4, 2015, 8:49 am

    Oy vey, yes it is a very nice looking shooting iron SIG has there – and not especially pricey. At least to buy. I cannot help but believe that builders of these types of firearms are in cahoots with ammunition makers and gun-cleaning manufacturers. Blast away and soon you’ll find that the inexpensive 5.56 and 7.62×32 really ain’t all that cheap after all. And we haven’t even gotten to the part where the weapon says “Clean me. Clean me” because these styles of firearms are among the most demanding of cleanliness and also require more accessories than our daughters’ Barbie Doll collections. But if you have the bucks to keep you supplied in ammunition without having your better half run interference and if you have way lot of spare time to rub and scrub, have at it. Like P.T. Barnum said: “There’s one born every minute.” or even better, the one from newspaperman H.L. Mencken: “You can never go broke underestimating the intelligence of the American public.” Such firearms as this one prove both points.

    • David Barmore March 26, 2015, 2:54 pm

      I can understand where you are coming from. But I don’t think understand what these weapons systems were designed for. I am a security contractor that operates all over the world. In this industry we need the very best products that we can get. These weapon systems are not a Ruger 10/22 that was designed to shoot at tin cans, these are made with the professional in mind.

  • Joe February 4, 2015, 7:05 am

    Shes a beaut !!
    Brother can you spare a lot of hundred dollar bills….

  • onebeener February 4, 2015, 5:40 am

    Nice & way cool !! by the time you get all the attachment you may have $3500 bucks in it and I’am a gun nut too
    Sorry folks I’am not a rich nut

    • Kyle February 4, 2015, 9:03 am

      Yea, most of the “new” stuff that companies have been making their own version of this year just seem to be flashy-er more expensive versions of what could be fun, affordable carbines. Instead they inflate their prices based of gobment contracts.

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