Looks like SB Tactical is making a new collapsing brace for the Sig MCX rifles. From what I have read online, the collapsing MPX brace is not compatible with the MCX. If you look at the photo above, the adapter that attaches the sliding bars to the MCX receiver is different than on the MPX.

This MCX is in .300blk and Alex says it suppresses very nicely with sub sonic loads. This could be a contender to the old AAC and new Q Honey Badger.


  • TheNotoriousIUD

    Shooting that with a dumb pistol brace must be like getting a kiss from your sister.

    Ok, maybe a cousin.

    • Gary Kirk

      Guess that kinda boils down to the state you’re in.. Some places that’s a normal thing..

    • Flounder

      But you see, if you are adopted….. Does it matter?

    • Jeff Smith

      either way, just don’t let anyone catch you doing it.

  • Suppressed

    SBTac’s new braces look amazing. I hated the first gen/wave of their products. I mean, they revolutionized things with their products and I’m grateful for that, but they were just aesthetically hideous. I think they kind of realized this and made several of their new models to visually mimic “real” stocks. Like the ones they came out with for the HK’s, Vectors, these Signs stocks, and even the new AK and AR ones. I’m now starting an AR pistol build that will use one of the new braces because they won’t trigger my autism nearly as bad as the old ones.

    • BaconLovingInfidel

      Yep, major props to SB tactical for pushing the envelope.

  • M@

    It will fit the MCX. The adapter is the same. I already tried it on my MCX.

    • Claymore

      The first gen of the SB Tactical Brace is not cross-compatible (The batches that were released in September), however, the gen 2 ones fixed this issue. You most likely have the Gen 2 SB Brace

  • noob

    yikes. nobody will want a pistol caliber semi-auto subgun anymore when you can get this without a tax stamp.