CSMR® Button

(29 reviews) Write a Review
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Product Overview

CSMR® Button - Concentric Spring Magazine Release button for M4/AR style rifles. The CSMR features two bosses on the backside to help keep the spring concentric during compression, and a raked 8 degree face for a more natural finger placement. Keeping the spring concentric during compression helps eliminate the crunchy feel when depressing. Offered in two styles, "MilSpec" (visually looks like the MilSpec fingerprint with all the updated features of the CSMR) or "Apex" (a mild yet grippy texture) to accomodate both the agressive or more conservative style of AR's. Also included is one of our 302 Stainless Mag Catch Springs (also available separately for purchase here) for even smoother compression, Patent Pending.

Only includes the Button and Spring

Ships Free and Made in USA 

  • CNC Machined 
  • 8 Degree Raked Face
  • Machined Logo
  • Two Button Styles 
  • 302 Stainless Spring Included
  • Weight: 0.07oz (including spring)
  • Material: 6061-T6 Aluminum
  • Finish: Type 03 Hardcoat Anodizing
  • Color: Carbon Black, Terra Bronze®



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

For all patents and trademarks, see


(29 reviews) Write a Review

29 Reviews Hide Reviews Show Reviews

  • 5
    Best in the Game

    Posted by Joe Stilinovic on Feb 21st 2024

    The CSMR is my go to mag release button. I have one on every rifle I own- 8° slant is great, 7076 aluminum, what is there to not like? I’ll recommend this until I die

  • 5
    Best on the market

    Posted by Joe Stilinovic on Jan 27th 2024

    Have one in every rifle I own. The 8° slant is perfect, zero wobble, and like $20 w/ fast shipping. I recommend this everyone

  • 5
    Cooler than Stock

    Posted by Spencer W on Jan 22nd 2024

    I bought this because I wanted my lower to be completely customized and liked the color and design on the CSMR. I didn’t realize it was angled which makes releasing mags feel smoother. Th CSMR enhances the cool factor of your rifle and the overall feel while being a solid purchase if you’re looking to upgrade your lower/ rifle’s look.

  • 5
    Great Product

    Posted by Jordan on Jan 14th 2024

    Definitely an improvement over stock

  • 5
    Great texture/function

    Posted by Malek on Jun 15th 2023

    Mainly got it for the color, but now realize it takes less effort/force to drop a mag due to the even distribution of the force with the spring/button recess! It's great!

  • 5

    Posted by Corey Starr on May 31st 2023

    Being able to source parts from a local and quality manufacture is the best. The texture of the Apex feels great while letting you know "that's the mag release" for sure. The 302 spring doesn't feel weak or over stiff. Making for a great experience all around.

  • 5
    CSMR button

    Posted by Cooper on Feb 26th 2023

    The CSMR button is a great add. I’ve bought them for every AR and MCX in the safe. I’m a princess and I hate shooting rifles without CSMRs now.. thanks RailScales for making a product that I can’t shoot without.

  • 5
    Terra Bronze MilSpec CSMR Button

    Posted by Nick on Dec 21st 2022

    Looks and feels good. Color matches well with Radian Brown

  • 5

    Posted by Tito on Nov 18th 2022

    What sweet button, feels fine. Nothing too jagged when I'm not wearing gloves. But we all know looking good is half the battle and this d**n thing looks gooood. I love how the terra bronze fits with the anodized green lower.