CMMG | BANSHEE MK4 UPPER GROUP | 5.56×45 | 10.5

The CMMG Banshee Mk4 upper group is a factory-complete, ultra-compact upper built for 5.56 platforms. At 10.5 it is configured for maximal maneuverability in compact AR15 builds while coming complete with a bolt carrier group and ZEROED accessories. This upper is suited to ultra-compact range builds and close-quarters training or carbine-style competition stages. It is built on the Mk4 platform and features CMMG components throughout.

Product Specifications

• The platform is Mk4.
• The caliber is listed as 5.56mm 5.56x45mm.
• The operating system is Direct Impingement.
• The barrel length is 10.5.
• The barrel twist is 1:7.
• The barrel material is 4140CM SBN.
• The muzzle device is the CMMG ZEROED Linear Compensator.
• The muzzle thread is 1/2 x 28.
• The gas port location is Carbine.
• The gas block is 0.750 Non-Adjustable.
• The upper receiver is made from Billet 6061 T6 Aluminum.
• The hand guard is the CMMG EML9 M-LOK.
• The finish is Cerakote Standard.
• The charging handle is the CMMG ZEROED Ambi.
• The UPC is 810097504035.

This upper ships as a turnkey option for builders who want a compact 5.56 platform without sourcing multiple components. Its billet receiver and complete ZEROED accessories simplify assembly while the short barrel and dedicated compensator keep the package compact for specialized short-barrel or maneuverability-focused builds.