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004-SD BU40-NiB-ECHO-D2-M

Made with 8620 AISI steel and boasting a Nickel Boron finish, the Stern bolt fits into Mil-Spec and Glock-pattern upper receivers.  It functions with Colt SMG, Glock magazines and it's fully compatible with standard AR15/M16 charging handles. Comes fully assembled with all sub-components installed, including firing pin/spring/retaining pin, extractor, and extractor spring.   Also included in bolt assembly is a propriety center and roll pins.  Our 40SW bolts incorporate our new bolt design which caters to single stage triggers with short resets.  It also allows use with the JP silent capture spring but is not recommend for 40SW applications. This bolt is compatible with the Law Tactical folding stock and the Echo trigger.

Technical Information:

  •     Made in U.S.A.
  •     Constructed from 8620 AISI steel.
  •     Custom 4140 billet extractor providing superior ejection.
  •     Glock cut.
  •     Coating: Nickel Boron
  •     Weight: 15.5 OZ with weight 13.3 OZ without.
  •     .40SW
  •     Compatible with single stage short reset triggers.
  •     Compatible with the Law Folding Tactical Stock
  •     Compatible with the Echo trigger.
  •     Compatible with the JP Silent capture spring (Not recommended)


7 Reviews Hide Reviews Show Reviews

  • 5
    Smooth as silk

    Posted by Eric Dochnal on Apr 24th 2023

    Bought this upgrade for the Stern 40 upper. After shooting a bunch of rounds this cleaned up extremely easy. Wish the inside of the receiver had this coating, it is beyond smooth and glides flawlessly with just a drop of oil. Should have looked into these years ago.

  • 5

    Posted by Robert Spears on Aug 13th 2022

    By far the heart and soul of this build. Very solid, well made, operated without a single failure (100 test rounds). I will recommend this BCG to any that asks.

  • 5
    Perfect for what it is.

    Posted by Paul Blount on Aug 10th 2022

    As I've stated in other reviews, Stern is one of the few companies that still support those of us that still support .40 S&W. Contrary to the internet and its desktop "warriors" .40 is not a dead caliber and is an excellent choice for self-defense and general shooting. This BCG is absolutely the best I've found. I have used the BCGs on about a half-dozen AR-40 builds and they are reliable with every kind of ammo I've thrown at them. They will work with any blow-back build. They will not work with proprietary "rotary-delayed" or "roller-delayed" systems, so know what you are building. Otherwise these are perfect.

  • 5
    Great NIB ECHO bolt for 40cal/10mm

    Posted by Unknown on May 10th 2022

    The bolt works great for 40 cal and 10 mm. No jams or misfires.

  • 5
    Well made

    Posted by Gooseslayer on Nov 10th 2021

    Very accurately made. Superb finish. works well.

  • 5

    Posted by Bryan T on Jun 11th 2021

    NB finish is super smooth and clean! Fit is spot on! 100+ rounds and almost zero wear marks! Another amazing product from Stern!

  • 5
    NiB Echo bolt finish - best ever

    Posted by RoCo on May 15th 2020

    This is the best finish I've seen on any internal part. Almost wanna leave it on the mantle as modern art.