BCM® MK2 Standard 9" 300 BLACKOUT Upper Receiver Group w/ MCMR-8 Handguard

MSRP: $1,002.10
Your Price: $743.49
(You save $258.61 )
(24 reviews) Write a Review
300 BLK
Barrel Length:
Barrel Style:
Upper Receiver:
Stock Status:

Out of stock

BCM® 300 Blackout Upper Receiver Groups
Continuous taper barrel profile designed for optimal weight, balance, and performance.
Barrel profile fluted toward the rear near chamber area - Increases strength and heat dissipation.
Tapered barrel profile out front, for easier maneuverability.
No sharp handguard cap shoulder for improved barrel harmonics and improved accuracy.
Muzzle threaded in standard 30 cal (5/8x24)
  • Includes MCMR-8 Handguard
  • Include MCMR-SM (MCMR Sling Mount)
  • Includes One 3" Picatinny Rail SectionIncludes
  • Includes BCM® Comp Mod 1 - 762/300 BLK


Featuring BCM’s Patent Pending MK2 Upper Receiver

This proprietary design offers enhanced rigidity over the USGI product.  The increased rigidity limits barrel deflection which aids in consistency/accuracy.   Less flex also reduces premature damage, wear, and failure of bolt lugs from misalignment.   A gas expansion chamber is machined above the charging handle track, combined with dual vents machined at the rear (each side, above charging handle latch) help to redirect and vent gas away the shooters face. 

BCM® has taken great care to ensure the best possible performance and interchangeability. However, due to the large operational range of 300 Blackout ammunition in the market place, BCM® cannot guarantee function will all ammunition types in all conditions. These barrels were designed to run with a carbine buffer with subsonic ammo and a H3 buffer with high velocity ammo. Fine tuning may be required in limited instances based on ammo and buffer choices that work best for the desired application. BCM® also recommends running the Crane O-ring (provided with all BCM® Bolt Carrier Groups) over the extractor with 300 Blackout.

  • Caliber: 300 Blackout
  • Barrel Length: 9"
  • Barrel Material: 11595E Spec Steel
  • Barrel Finish: Manganese Phosphate (Mil-Spec A-A-59267)
  • Bore & Chamber: Chrome Lined
  • Weight: 2.2 lbs
  • Twist Rate: 1:7
  • Gas System: Pistol
  • Muzzle Device: BCM® Comp Mod 1 (762/300BLK)
  • Muzzle Threads: 5/8x24
  • Handguard: MCMR-8

Copyright 2017 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.***

24 Reviews

  • 5
    BCM 9 inch 300 blk out

    Posted by Blaine Pitcher on Jul 24th 2020

    Full disclosure: I'm a BCM fan boy.
    This upper is amazing!

  • 5
    BCM® MK2 Standard 9" 300 BLACKOUT Upper Receiver Group w/ MCMR-8 Handguard

    Posted by Brett Rayl on Jul 18th 2020

    BCM is second to non in my book. This upper is everything I imagined and more! Absolutely love the changes that have been made and thank god someone has finally minimalized the forward assist that gets will almost never be used on even a semi well kept rifle. Thank you BCM for continuing to be innovative while keeping quality to the highest standard.

  • 5
    9" 300 BLK

    Posted by Daniel Crowe on Jul 18th 2020

    Cant beat BCM for the value! Best value and most reliable on the market!

  • 5
    MK2 Upper 9” MCMR-8

    Posted by Josh on Jul 6th 2020

    Received this upper last week. Still waiting on some other custom parts (trigger, charging handle, etc) for my 300 blk buildout but I can’t wait to shoot it! This upper is extremely durable and very lightweight. It fit perfectly with my Aero Precision M4E1 lower receiver. Very happy with this purchase.

  • 5

    Posted by Tony on Jun 29th 2020

    Fit and finish are unmatched, exceeds expectations.

  • 5
    300 Blackout

    Posted by Gary Miner on Jun 15th 2020

    The 300 blackout came as advertised. I have been admiring the quality and precision of the workmanship that has went in to making this weapon .

  • 5
    BCM 300blk Upper

    Posted by Jason on Jun 15th 2020

    I looked around for a long time at uppers. I almost bought a Larue until I found this one for a better price. This is my first BCM upper and I have to say, I am very impressed. The fit and finish is better than most and the tolerances are very tight as they should be.

    I really like the redesign of the upper and look forward to the added durability. After putting 500rds suppressed through this upper I can say that this will most likely be more capable in reguards to accuracy than most will be able to shoot. I don't say that lightly, I was a sniper in the Marine Corps and can usually identify rifle capabilities pretty quickly. Also no FTF's using sub ammo of many variations. I also noticed that I did not experience excessive gas to my face when suppressed, I am running a deadair wolfman if anyone is curious.

    Overall I am very impressed and will use BCM for other builds. I honestly believe that the quality exceeds the cost of this upper. This is certainly not the case for others that I have purchased from other manufacturers.

    Keep up the great work!!

  • 5

    Posted by Anonymous on Jun 8th 2020

    Excellent quality and rigidity. Probably best upper I’ve owned, nothing less expected from BCM!

  • 5
    BCM-mk2-urg 300 BOL-9 Mc Mt-8

    Posted by Jairo H. on Jun 1st 2020

    Amazing product the weight is phenomenal and the parts very sturdy! Very satisfied with these product.