MCX CSMR® Button

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Product Overview

MCX CSMR® Button - A MCX version of our popular M4 CSMR button. The MCX CSMR mag button features the same 8 degree raked face for a more natural finger placement. Installs low enough to clear reciever fencing or as far off the reciever as desired. Offered in our "Apex" face (a mild yet grippy texture) to accomodate both the agressive or more conservative style of MCX's. Also included is one of our 302 Stainless Mag Catch Springs (also available separately for purchase here) for even smoother compression, Patent Pending.

Also compatible with Sig MPX, M400 Switchblade, M400 SDI VTAC, 716i, & 762G2 (the ambi bolt release may prohibit button from sitting below recevier fencing on 716G2). 

Only includes 1x Button & 1x Spring

Ships Free and Made in USA 

  • CNC Machined 
  • 8 Degree Raked Face
  • Machined Logo
  • 302 Stainless Spring Included
  • Weight: 0.08oz (including spring)
  • Material: 6061-T6 Aluminum
  • Finish: Type 03 Hardcoat Anodizing
  • Color: Carbon Black®, Terra Bronze®



© 2024 RailScales LLC All rights reserved. RailScales®, CSMR®, Carbon Black®, Terra Bronze® are registered trademarks of RailScales LLC.

For all patents and trademarks, see


(7 reviews) Write a Review

7 Reviews Hide Reviews Show Reviews

  • 5
    Fantastic Upgrade

    Posted by William Lyon on Feb 8th 2024

    Another great railscale upgrade a finely crafted add-on. It was a very simple install and I couldn’t be more pleased

  • 5
    Mpx mag button

    Posted by Brendan Garcia on Apr 6th 2023

    Definite upgrade to my Mpx k model. (Yes the 9mm platform) when I release the mag, my thumb just sticks to this button.

  • 5
    It’s the little things

    Posted by Cody on Nov 5th 2022

    This button is exceptionally well made, the finishing on it is much better than the original and the few millimeters of extra protrusion make dropping the mag with gloved hands much easier, not to mention the little style difference draws your eyes to the little details of the build. Now they just need a matching bolt catch with a larger paddle!

  • 4
    Good Part

    Posted by Clint Blumenberg on Jul 23rd 2022

    Install was a bit of a pain, mine didn't seem to fit quite right and got stuck a few times. But once installed, it's quite good.

  • 5
    MCX CSMR Button

    Posted by Brandon Hann on Jun 19th 2022

    this is a must do upgrade. I put this into my MPX and it is AWESOME! 12/10! The look is sick, the texture is great, super high quality.

  • 5
    Freakin awesome

    Posted by Gary S on Jun 12th 2022

    Definitely worth it. Its a small addition that goes a long way. Texture is easy feel but not so rough it will catch on clothes. Worth the money.

  • 5
    mcx csmr

    Posted by Willy on Jun 9th 2022

    awesome upgrade