BCM® SS410 20" Complete Upper Receiver Group w/ KMR-A15 Handguard

MSRP: $976.95
Your Price: $863.95
(You save $113.00 )
Maximum Purchase:
5 units
5.56 NATO
Barrel Length:
Barrel Style:
Stock Status:

About the BCM® SS410 20" Complete Upper Receiver w/ KMR-A15 Handguard

All BCM® Upper Receiver Groups with a KMR-A Handguard Include:

  • One 3" Picatinny Rail Section
  • One BCM KeyMod Sling Mount

Manufactured by Bravo Company MFG, Inc. (BCM)

These Barreled Upper Receiver Groups are designed for shooting professionals and responsible civilians with the Mil-Spec features for the demands of their duty. They are fully assembled, headspaced, and test fired.
As a note: Prior to shipping, all BCM upper receiver groups are test fired for function, laser bore sighted with a Milspec carry handle for sight alignment within Mil-Specs, and then batch samples are test fired for accuracy. As such, the upper receiver group will show handling marks consistent with these quality control procedures.

SS410 Barrel Steel

This 20" BCM barrel is machined from SS410 stainless steel. Featuring hand lapped 1/8 twist rate button rifling and M4 feed ramps barrel extensions, the 410 stainless barrel gives the shooter the best balance of weight and accuracy. 410 stainless is also harder and more corrosion resistant than conventional 416 stainless found in other commercially available precision barrels.

M4 Feed Ramp Barrel Extension and Upper Receiver

In developing the USGI M4 carbine as one of the primary weapons for today's infantry, some modifications were performed to the original M16 platform to enhance the reliability of the shorter barreled carbines. With the shorter carbine gas system and the increased gas port pressure, the carbine cycled faster, and at times the cycle rate could be faster than the magazine would feed ammunition. One of the modifications done to increase reliable feeding included enhancing the angle and the length of the feed ramps.
This USGI modification was done to both the barrel extension and the upper receiver, creating a longer and steeper feed ramp. These Mil-Spec M4 feed ramps are part of the original CNC manufacturing process. As a result, the factory machined M4 feed ramps on the receiver are hard coat anodized which adds significant strength to the aluminum. This feature is offered on all BCM upper receivers and all BCM barrels.

T-Marked Upper Receiver

The contemporary M16/M4 rifle is built around the concept of modularity. All of the BCM flat top uppers feature a USGI type laser etched T-marks to provide addressing for the remounting of tactical accessories such as optics, laser sights, etc. This enables the weapon platform to be easily configured and then accurately reconfigured for each specific mission.

5.56 NATO Match Chamber (USMC SAM-R Chamber)

The USGI 5.56 NATO chamber is the best choice for effective deployment, reliability, and compatibility, of higher chamber pressures of military or high quality personal defense ammounition.  The SAM-R chamber is the precision version of the 556 NATO chamber.

Shop Related Products:

Want to see more upper receivers? Click the links below to view more BCM® AR complete uppers!


Bravo Company builds: Life Saving Tools™
Copyright 2023 Bravo Company MFG, Inc.
***This product contains chemicals/materials known to the State of California to cause cancer and other reproductive harm. To learn more, visit www.p65warnings.ca.gov.***

15 Reviews

  • 5

    Great product

  • 5
    Great product / great service

    I haven't had a chance to shoot this upper yet as I'm still waiting for my lower to arrive. I can tell you from all appearances, it looks to be of very high quality. Service is also excellent. I didn't expect it to be shipped right away, in light of current high demand, but it was sent out the day after I placed the order (and I ordered late in the day). I also asked a question about the lower by email, not expecting to hear anything for a couple days, and they answered the same day with a very detailed and helpful explanation. This company is the real deal.

  • 5
    Best I've ever had.

    Look's great, operates like it should.

  • 5
    Bravo co. Is the only way to go!

    I have purchased 7 complete upper receivers, many lower parts kits and stock assemblies, in addition to several other odds and ends from BCM. Not only are the products always top notch compared to any other company I've purchased from, but every order is delivered extremely fast and without issue. One upper receiver I purchased had a loose low profile gas block which BCM promptly sent out a return label for. No questions asked. They treat every purchase as a top priority and I can honestly say I will never purchase my AR15 parts or rifles anywhere else but Bravo Co. Thank you all for upholding a very high standard in a world gone to mass production garbage! Many more purchases to come.

  • 5
    Less than .5" groups

    I ordered this upper a while ago. Should have reviewed earlier but I started reloading recently and with my 77gr noslers I am getting some tiny groups. Best one the other day measured .48" @100 yds with a 3.5# trigger. Only problem is I wear the hat they sent with it so much it looks pretty sad at this point.

  • 5
    Superb Upper!

    Granted, I'm not an expert by any stretch of the imagination but I purchased this upper receiver group to marry it with a lower that my Son & I put together and we could not be more pleased. It has functioned flawlessly for the first several hundred rounds. My only comment is that the one I clicked on and put in the cart was the stainless steel barrel without the Ion bond finish - but when the package arrived - the barrel with the ion bond was with my upper receiver & handgaurd - I shouldn't really complain as this was a more expensive option.

  • 5
    Amazing product and speed.

    I ordered my complete upper on Sunday and they had to have me call them Monday to confirm my address. So I figured thur or Fri for my order to be in. It showed up tues.

  • 5
    Excellent for a DMR

    As always BCM quality is hard to beat at any price. I bought this 20" upper as a precision build. I received it very quickly with no issues. Looking forward to seeing how well it does on the range.

  • 5
    Awesome all around experience

    Freaking awesome!!!! Exceeded all expectations!