The CMMG Banshee MK4 Upper Group (brand part number 30B8A6FAB) was designed from the start for the AR15 platform, built to use many of the AR’s most common components while running .300 Blackout. Built by CMMG with a 12.5-inch barrel, this Direct Impingement upper works with any standard AR15 lower group and ships complete with a bolt carrier group and CMMG’s ZEROED accessories, including a polymer dust cover, an ambidextrous charging handle, and a .308-pattern linear compensator, all finished in Cerakote.

Key Specifications

• Chambered in .300 Blackout on the Mk4 platform.
• Barrel length is 12.5 inches.
• Operating system is direct impingement.
• Twist rate is 1:7, matched to a wide range of .300 BLK bullet weights.
• Barrel material is 4140 chromoly steel with a salt bath nitride finish.

Frequently Asked Questions

Does this upper include a bolt carrier group? Yes, all CMMG Upper Groups ship complete with a bolt carrier group and CMMG’s ZEROED accessories.

What lower does this upper work with? It works with any standard AR15 lower group.

Buy the CMMG Banshee MK4 .300 Blackout Upper

Build a compact .300 Blackout AR with character on a proven Mk4 upper group. Order this AR-15 upper from our Lubbock, Texas gun shop, and we will get it to your door as soon as it’s ready to ship.