SIG Introduces The MCX Carbine

SIG is aggressively pursuing a revamped lineup for 2015. As part of this, they have announced a new carbine: The SIG MCX.


SIG is being fairly tight-lipped about the carbine, but claims it is “the first to be designed from the start as a silenced, short-barreled rifle chambered in 300BLK” the truth of which depends on your definitions of most of the words in that clause. The enlarged upper receiver suggests the rifle utilizes an operating rod of some kind.

The new weapon will be offered as an SBR, pistol, and a 16″ barreled carbine. SIG has not yet announced a price.

MCX_SBR2 MCX_Pistol2 MCX_Carbine2

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


  • floppyscience

    Aww, no SIG “muzzle brake”?

    • dave

      let’s be honest, though, who wouldn’t buy one of those “muzzle breaks” and not strongly consider making a suppressor out of one.

  • Esh325

    I think Sig’s product line is really muddied. They have a DI AR,gas piston AR,Sig rifle, and now they have another rifle which doesn’t appear to have commonality with an AR15.

    • JumpIf NotZero

      The MCX lower is AR-15 compatible.

      • Esh325

        Oh I stand corrected then.

    • billyoblivion

      “Muddled” or “Broad”?

      And “doesn’t appear to have…an AR15”?

      Did you look at the receiver? It’s got the selector in the same spot (although ambi-), it’s got the forward assist in the same place (implying a bolt carrier that is at least superficially similar to the AR, which also implies DI), uses magazines that LOOK standard AR/M16 mags. etc.

      • billyoblivion

        Looks like I’m wrong about the DI part.

    • Frank

      Maybe that’s where all of these weird quality issues keep coming from. They’re making way too many guns for how large they are and QC is getting way too complicated. Like how a small restaurant can have way too large of a menu.

      • FourString

        Like that small town restaurant that has Chinese, Indian, Thai, Japanese, and Korean food all under one roof except it doesn’t really taste like any of those nor does it taste good.

  • Interesting guns, hopefully they run as good as they look.

    And hopefully the price is somewhat reasonable.

  • 1111

    what an ugly rifle

  • I will be at the SIG event rather than Media day. They will have the MCX I’m sure as well as the P320 45 compact. I should be able to shoot them both. If it’s there I’ll write it up Monday night and post it immediately.
    Yes most of them can be used with AR grips. Hey no such thing as a stupid question!

    • Giolli Joker

      “Hey no such thing as a stupid question!”
      You are on the Internet, be careful with similar declarations.

  • These photos were sent to us they aren’t ones we took.

  • sianmink

    No buffer tube, so yeah. I like that. It probably operates like a LR-300. I’d like to see a forward charging handle on that thing. Much as I like the AR15 platform that T handle is a plague.

  • andrey kireev

    I’m just not sure how to feel about that stock…..

    • Stock looks pretty light, front end looks pretty heavy.

  • It should be fun I’ll certainly say that. We all pay with working a lot of those 14 hour or more days but in the end it’s worth bringing the news to everyone:-)

  • How so what’s wrong with it?

    • Tim Pearce

      They don’t actually exist yet. That’s what’s wrong. Announced a year ago, and have never been available in the semi-auto pistol or carbine formats. I’m a dealer, and have been trying to get one for a year.

  • hami

    The SIG brace looks pretty natural on there.

  • Carlos Velazquez

    They must have forgot about the Spike’s Tactical Compressor.