CMMG BANSHEE MK4 Upper | .300 BLK | 12.5

The CMMG BANSHEE Mk4 upper group is a complete AR-15 compatible assembly chambered for .300 BLK with a 12.5-length barrel. It ships with a bolt carrier group and ZEROED accessories including an ambidextrous charging handle, polymer dust cover, and CMMG ZEROED linear compensator. The billet 6061 T6 upper and CMMG EML11 M-LOK hand guard create a compact, modular platform for short-barrel AR builds. Well suited for range-focused compact setups and short-range field use.

Product Specifications

• The platform is Mk4.
• The caliber is .300 BLK.
• The operating system is Direct Impingement.
• The barrel length is 12.5.
• The barrel twist is 1:7.
• The barrel material is 4140CM SBN.
• The barrel contour is MR.
• The muzzle device is a CMMG ZEROED Linear Compensator.
• The muzzle thread is 5/8 x 24.
• The gas block is 0.750 Non-Adjustable.
• The upper receiver is Billet 6061 T6 Aluminum.
• The hand guard is a CMMG EML11 M-LOK.
• The finish is Cerakote Standard.
• The charging handle is CMMG ZEROED Ambi.
• The UPC is 810097502499.

The BANSHEE Mk4 upper group is a purpose-built component set for building a compact .300 BLK AR platform without sourcing parts separately. Its billet receiver, integrated M-LOK hand guard, and included ZEROED accessories make it straightforward to assemble a short-barrel recreational or field-oriented AR build while retaining modularity for common AR components.