Description
MPN: 30B8A6F-AB
Features:
- Caliber: .300 Blackout
- Finish: Armor Black Cerakote
- Upper Receiver: CMMG Mk4 Upper Receiver - 6061-T6 Aluminum
- Handguard: 11-Inch CMMG EML11 Handguard
- M4 Feed Ramps: Yes
- Muzzle Device: CMMG .308 ZEROED Linear Compensator
- Barrel: 12.5" 1:7 Salt Bath Nitrided 4140 Chrome Moly Steel
- Muzzle Thread Pattern: 5/8"-24
- Gas Block: CMMG ZEROED Adjustable Gas Block
- Gas Tube: Pistol-Length Gas Tube
- Bolt Carrier Group: Mil-Spec M16 Bolt Carrier Group
- Charging Handle: CMMG ZEROED AR15 Ambi Charging Handle
- HP and MPI Tested
*This upper receiver assembly has a barrel that is shorter than 16". This upper is only for use on AR pistol lower receivers and NFA registered Short-Barreled Rifle (SBR) lower receivers. All NFA laws apply!
Specifications:
- Weight: ~3.62 lbs.
- Length: ~20.44"
Compatibility:
- AR-15 lower receiver
Includes:
- 1x CMMG Banshee 300 Blackout 12.5" MK4 Complete Upper
- 1x Mil-Spec M16 Bolt Carrier Group
- 1x CMMG ZEROED AR15 Ambi Charging Handle
Details:
The CMMG Banshee MK4 12.5" .300 Blackout Complete Upper is designed for shooters who want a compact platform that delivers meaningful performance without giving up control. The 12.5-inch barrel strikes a practical balance—short enough to stay maneuverable, yet long enough to maintain reliable dwell time and consistent performance with both subsonic and supersonic ammunition. Whether you’re building a defensive setup, a range-focused rifle, or a suppressor-ready configuration, this upper is built to handle it.
Adjustable Gas Block for Real-World Flexibility
One of the defining features of this upper is its adjustable gas block. The .300 Blackout platform is often used in multiple configurations—suppressed and unsuppressed, subs and supers—and a fixed gas system rarely does all of that perfectly. The adjustable setup allows you to fine-tune gas flow to match your ammunition and suppressor use, helping smooth out the recoil impulse and reduce unnecessary wear on internal components. Instead of compensating for excess gas elsewhere in the system, you can dial it in properly at the source.
MK4 Platform with Modern Modularity
Built on CMMG’s MK4 AR-15 platform, this complete upper is ready to pair with a compatible lower receiver. The free-float M-LOK handguard provides attachment points for lights, grips, and sling hardware without adding unnecessary bulk. A flat-top receiver keeps optic mounting straightforward, whether you’re running a red dot for close-range work or a low-power variable optic for extended capability.
A Purpose-Built .300 Blackout Upper
If you’re assembling a .300 Blackout rifle or pistol and want a factory-built upper that combines compact dimensions, adjustable gas control, and proven CMMG construction, the Banshee MK4 12.5" Complete Upper delivers a dependable, versatile foundation. It’s a platform designed to take full advantage of what .300 Blackout does best—flexibility, control, and practical performance.
