The Brownells BRN-180® SCNR 9” .300 Blackout Complete Upper Receiver Assembly is the compact, suppressor-focused configuration in the SCNR family. The 9” barrel is an excellent match for .300 Blackout, delivering strong ballistic performance from a short barrel while keeping the overall package exceptionally compact and maneuverable. This configuration takes advantage of the efficient short-barrel performance that makes .300 Blackout especially well suited to compact rifles without adding unnecessary overall length.
That compact footprint becomes even more valuable when a suppressor is added. Combined with the BRN-180’s self-contained, buffer-tube-free operating system and compatibility with Picatinny-mounted folding-stock configurations, the 9” upper can remain highly compact for transport, storage and use even with a full-size suppressor installed. The result is a configuration built around the strengths that make suppressed .300 Blackout especially effective in short, maneuverable platforms.
The 9” barrel uses a fast 1:6” twist rate selected to stabilize the long, heavy projectiles commonly used in suppressed .300 Blackout loads. That added rotational stability supports accuracy with heavy subsonic ammunition and helps those projectiles perform more consistently on target, supporting more predictable terminal performance. The 9” SCNR is therefore particularly well suited to shooters building around suppressed .300 Blackout performance without giving up the ability to run supersonic ammunition.
Its 3-position adjustable gas system is tuned around the 9” .300 Blackout configuration for Suppressed, Normal and Adverse operation. The gas system has been extensively tested and optimized for reliable suppressed operation with both traditional and flow-through suppressors. Underneath those cartridge-specific advantages is the proven AR-180-based short-stroke gas-piston operating system and self-contained, buffer-tube-free bolt-carrier assembly that define the BRN-180 platform.
The left-side charging handle stays stationary during firing, keeping it clear of the shooter and support hand as the action cycles. Its location also allows the support hand to operate the action while the firing hand remains in position.
The streamlined charging handle angles downward for easier access and improved clearance around mounted optics. The shape also provides a more natural grasp when charging the upper or manually locking the bolt to the rear.
A protective rubber gasket seals the charging-handle channel while allowing the handle to move freely. The sealed opening helps keep dirt, dust and debris from entering the receiver and reaching internal components.
The traditional hinged dust cover is replaced by a carrier-mounted ejection-port cover. It opens automatically as the bolt carrier cycles and closes when the action returns to battery. An AR-15-style shell deflector sits behind the ejection port to help manage ejected cases, while the automatic cover helps protect the receiver from external contaminants.
Select Suppressed, Normal or Adverse gas settings through the handguard without tools. The gas system is tuned around the 9” .300 Blackout configuration and has been extensively tested and optimized for reliable suppressed operation with both traditional and flow-through suppressors. The gas block and valve use a Chromium Tungsten Nitride finish to help reduce carbon fouling, while solid handguard material around the vent area helps deflect gas away from a forward support hand.
A retention system keeps the guide rods, recoil springs and bolt-carrier assembly securely contained when the upper is opened or removed from the lower receiver. Press the release when it is time to remove the assembly for controlled field stripping, cleaning and maintenance.
The BRN-180® SCNR uses upgraded flat-wire guide-rod springs to help drive the bolt carrier fully into battery as fouling builds. An anti-bounce bolt-carrier design helps prevent the carrier from rebounding after it closes, supporting reliable ignition and cycling. A full-length steel cam path reduces wear between the steel carrier and aluminum receiver during extended use, including suppressed shooting.
A strengthened handguard attachment interface provides a rigid, low-flex foundation for optics, lights, lasers, grips and other accessories. Ambidextrous QD sling sockets use hardened steel inserts for added durability and flexible sling placement. At the muzzle, an added barrel flange provides cleaner muzzle-device fitment without the special adapters required on earlier BRN-180 generations.
Warning: Do not cycle the action of you BRN-180 SCNR if the upper receiver is not installed on the lower receiver. Doing so could damage the recoil spring guide rod assembly.
SKU:
Barrel Length (in):
Length (in):
Weight (lbs):
Contour:
Gas Block (dia in):
Barrel Finish:
Twist:
430119682
13.90
23.25"
4.82 lbs.
Lightweight
0.75
Nitride
1-8"
430119681
10.5
18.5"
3.95 lbs.
Lightweight
0.75
Nitride
1-8"
430119680
9.00
17.5"
3.95 lbs.
Lightweight
0.75
Nitride
1-6"
WARNING!: BE SURE TO READ AND FULLY UNDERSTAND YOUR USER MANUAL BEFORE USE. FAILURE TO DO SO MAY RESULT IN DAMAGE TO THE FIREARM, SUPPRESSOR (IF INSTALLED), AND/OR PERSONAL INJURY INCLUDING DEATH. Brownell’s BRN-180 SCNR Uppers are designed and tested to operate reliably with knowledgeable use and proper care. The use of super-sonic, sub-sonic and standard ammunition loads with or without suppressors will require adjustment of the multi-position gas block system. Failure to adjust the system properly can result in damage to the firearm, suppressor (if installed), and/or personal injury including death. If there are any questions, please contact our Customer Service Department at 1-800-741-0015 available
Monday thru Friday 08:00 to 05:00 Central Time.
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