BCM® SS410 18" Rifle Complete Upper Receiver Group w/ KMR-A13 Handguard 1/8 Twist

MSRP: $1,042.95
Your Price: $819.95
(You save $223.00 )
Maximum Purchase:
5 units
5.56 NATO
Barrel Length:
Barrel Style:
Stock Status:

About the BCM® SS410 18" Rifle Complete Upper Receiver w/ KMR-A13 Handguard 1/8 Twist

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 18" 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.***

17 Reviews

  • 5
    BCM Upper Receiver Group

    I've work on , shot and used AR's since the late sixties. This BCM SS410 18'' is extremely well made. I have a handicapped left hand and the KMR- APHA 13'' Handguard fits me well. I'm perfectly happy with my purchase. Mated it to a preban Colt lower fits perfect.Shoots a little over 1 MOA groups, will tighten up once barrel breaks in. Outstanding product keep it up.

  • 5
    Truly assume.

    The quality is just as was promised. I am looking forward to many years of service with this upper.

  • 5
    Great product

    This upper is made with great care and expertise.

  • 5
    Love it!

    So far so good. High quality, beautiful and it works great. I was happy with my 50 yard groups when I was sighting in, my hundred yard groups not so much. I blame the operator though... I've never shot at 100 yards so it's expected. Its not like the barrel is going to make me a marksman. Its a joy to shoot, now I just need to shoot more and get better.

  • 5

    Absolutely love it! Well made

  • 5

    Excellent service! Thanks!

  • 5
    They are the Best. Hands down.

    Got my Upper Receiver in a timely fashion and the build quality is amazing. No one produces this kind of quality at the price. Simply put; they are outstanding.

  • 5
    Great upper

    This is the second one I've purchased from BCM. I liked my first one so much that I decided to get another one with basically the same features except this one has a longer barrel. Perfect performance right out of the box.

  • 5
    Fantastic Service

    Very pleased and surprised at how quickly my order was processed and shipped. The upper group looks amazing, and I am anxious to get to the range to see how it shoots. I'm guessing I will not be disappointed.